An atlas of_head_and_neck_images__part_ii

Preface

An atlas of head and neck images, part II

Guest Editors

Part I of An Atlas of Head and Neck Images reviewed imaging for the head and neck in

trauma, chest pathology, and ultrasonography for the head and neck. It was offered both as an

overview of technology and as a simple guide for the interpretation of images common to oralandmaxillofacial surgeons, plastic and reconstructive surgeons, otorhinolaryngologists, and head

and neck surgeons. It was also intended as a useful tool for radiologists, neurosurgeons, general

surgeons, and the medical and dental communities at large.

Part II of our series begins with an exhaustive compendium of panoramic images. These are

provided not only as a quick review of common and uncommon pathoses of the mandible or

maxilla, but also as a visual reference for how these lesions are most likely to appear on pano-

ramic radiographs. The next article focuses on computed tomography of the head and neck, pro-

viding representative images of the most common pathologic head and neck entities. An articleon nuclear imaging provides a synopsis of the most frequently encountered vascular lesions of

the head, face, and neck. Finally, an article on magnetic resonance imaging complements the

two issues by providing one more additional imaging modality in the practitioner’s diagnostic

armamentarium.

Although this atlas series does provide an overview of signs, symptoms, etiology, and path-

ophysiology of a vast array of head and neck problems, it is not meant to be a definitive treatise

on injury and pathology. It is intended merely to quickly point practicing surgeons in the right

direction when specific conditions and problems in head and neck surgery are encountered. It ishighly visual in design so that it may serve as a quick and ready reference.

Richard H. Haug, DDS

Division of Oral and Maxillofacial Surgery

University of Kentucky College of Dentistry

D-509 Chandler Medical Center

Lexington, KY 40536-0297, USA

E-mail address: [email protected]

Charles Lee, MD

Division of Diagnostic Radiology

University of Kentucky College of Medicine

Chandler Medical Center


E-mail address: [email protected]

Charles Lee, MDRichard H. Haug, DDS

1061-3315/03/$ - see front matter � 2003, Elsevier Science (USA). All rights reserved.

doi:10.1016/S1061-3315(02)00027-6

Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) vii

Panoramic radiograph in pathology

Dean K. White, DDS, MSD*, Chad C.Street, DMD, MD,William S.Jenkins, DMDAnthony R. Clark, DMD,

Jason E. Ford, DMD

Division of Oral and Maxillofacial Pathology, College of Dentistry, University of Kentucky, 800 Rose Street,


The panoramic radiograph is an excellent extraoral radiograph to reveal abnormalities and

pathologic conditions of the jaws and to show calcification of adjacent soft tissue. A single pan-

oramic radiograph provides a significant image of the maxillofacial skeleton and dentition andoften is used as a survey or screening film because of the area it covers. The panoramic radio-

graph does not provide fine radiographic detail, however, and often is followed by intraoral

radiographs that can provide sharper detail of an abnormal finding. Computed tomography

(CT) and magnetic resonance imaging (MRI) often are utilized to further delineate the extent

of a pathologic process found on panoramic radiograph.

DEVELOPMENTAL DEFECTS

Exostosis/torus

Frequency/incidence

The incidence of exostoses of the jaws is approximately 27% [1]. The prevalence and numberof exostoses increase with age, and exostoses are more common in men than women. Palatal

tori, however, are more common in women. Tori are large exostoses of the midline of the hard

palate and the lingual surface of the mandible.

Signs and symptoms

Exostoses and tori are localized outgrowths or nodules on cortical bone, which usually areasymptomatic [2]. They may interfere with normal speech if excessively large and may become

inflamed and painful if traumatized.

Etiology/pathophysiology

These outgrowths of bone are composed of dense cortical bone but may contain medullarybone. Several theories have been proposed concerning the development of exostoses that impli-

cate genetic and environmental factors, including masticatory stress [3].

Image of choice for diagnosis

Exostoses and tori may be depicted on panoramic and periapical radiographs depending onthe size and density of the structures. The diagnosis of exostosis primarily is a clinical diagnosis,

which may be confirmed by the radiograph.

Image hallmark

If an exostosis is of sufficient size and density, it may appear as a well-defined radiopacity on

the radiograph in the area of clinical change (Fig. 1).

* Corresponding author.

E-mail address: [email protected] (D.K. White).


PII: S 1 0 6 1 - 3 3 1 5 ( 0 2 ) 0 0 0 1 2 - 4

Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) 1–53

Management

No treatment usually is necessary; however, exostoses and tori are removed when a prosthesis

is placed on the involved mucosa, when they are chronically inflamed and painful, and when

they interfere with normal speech.

Condylar hyperplasia

Frequency/incidence

Condylar hyperplasia is a developmental abnormality that results in enlargement and occa-

sionally deformity of the condylar head. This is an extremely rare condition with an incidence of

less than 1% [4].

Signs and symptoms

The clinical features include asymmetry of the lower third of the face, deviation of the man-

dible and chin away from the affected side, and compensatory vertical growth of the maxilla on

the affected side. Patients may also have significant temporomandibular joint symptoms, such as

pain, joint noises, and diminished mouth opening. The mandibular midline also may be shifted,

creating an anterior lateral crossbite with class III molar and canine occlusion on the affected

side [5–7].

In addition, the height of the ramus will be increased on the affected side.


The cause of condylar hyperplasia is unknown but may result from circulatory abnormalities,

previous trauma, hormonal disturbances, abnormal joint loading, genetic alterations, and as

representing a cartilaginous exostosis [5–7].


The panoramic radiograph is the initial screening film of choice. Further enhanced images

include conventional CT and MRI.

Fig. 1. Radiograph showing exostosis/torus.

2 D.K. White et al / Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) 1–53

Image hallmarks

The condyle may appear relatively normal in shape but enlarged (Fig. 2). It also may exhibit

alteration in shape and be more radiopaque. The ramus and mandibular body on the affectedside may also be enlarged, resulting in a characteristic depression of the inferior border of the

mandible where the enlarged side joins with the contralateral normal side. In addition, the con-

dylar neck is classically elongated on the ipsilateral side [8,9].

Management

Treatment decisions are primarily based on the age of the patient [8]. Treatment consists of

a combination of orthodontics and orthognathic surgery to correct the skeletal deformity andany dental malocclusion. Successful treatment has been reported with high condylectomy [7].

Calcified stylohyoid ligament

Frequency/incidence

Approximately 2% to 18% of the general population present radiographic evidence of ossifi-

cation of the stylohyoid ligament [10]. There appears to be a slight predominance for women,and symptoms are more common in patients aged 40 and older.

Signs and symptoms

Most patients are asymptomatic; however, when symptoms occur, there is no correlation

between the extent of the calcification and symptoms present. Eagle syndrome is a term used

to describe the cluster of symptoms experienced. The symptoms include pain in the peritonsillar

region and base of the tongue area posterior to the angle of the mandible, dysphagia and otal-gia. Eagle syndrome previously was reported only in patients post-tonsillectomy. Now it is

applied to patients meeting the criteria of the previously described symptoms, with elongated,

calcified stylohyoid ligaments [10–12]. Some patients may exhibit syncope when they quickly

turn their heads because the rigid ligament compresses the carotid artery and cervical sympa-

thetic chain (carotid artery syndrome) [12]. There also have been reports of cervical spine disease

resulting in difficult intubations in patients with calcified stylohyoid ligaments [13].


The stylohyoid ligament is a fibrous sheath that persists as a part of the ceratohyal element of

the second branchial arch, extending from the base of the skull to the lesser horn of the hyoid

bone and passing between the internal and external carotid arteries [14]. For unknown reasons,

this ligamentous structure may undergo ossification, especially in the upper part of the ligament.


The panoramic radiograph is the image of choice for visualization. The ligament also may be

seen on a routine skull series and cervical spine radiographs.

Fig. 2. Condylar hyperplasia. Enlargement of the left mandibular condyle (arrow). (Courtesy of Dr. Gary Reinhart.)

3D.K. White et al / Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) 1–53

Image hallmarks

Calcified stylohyoid ligament presents as a radiopaque change along the course of the struc-

ture in which the calcification may vary in density and length (Fig. 3).

Management

Treatment consists of surgical removal of the affected ligament as close to the cranial base as

possible in patients with significant symptoms [11]. This can be accomplished through either an

intraoral or extraoral approach, although the extraoral approach is preferred because of better

access and visualization.

Nasopalatine duct cyst

Frequency/Incidence

The nasopalatine duct cyst is the most common nonodontogenic cyst of the jaws with a pre-

valence of approximately 1% [15,16]. It is most frequently found in patients between the ages of

40 and 60 years, with a slight male predilection [17].

Signs and symptoms

Most patients are asymptomatic; however, pain, swelling, drainage, and movement of teeth

may be noted. A large cyst may present with palatal swelling in which the cortical plate has beenperforated and drainage of fluid or pus ensues.


The cause of the cyst is unknown, but some authors have attributed its development to

trauma, infection, and spontaneous proliferation of residual embryonal epithelium as possible

causes [15–18].


The panoramic radiograph is the initial screening film of choice, followed by periapical radio-

graphs for definitive visualization.

Image hallmarks

The classic presentation is a symmetrical, ovoid or heart-shaped radiolucency between the

roots or at the apices of vital maxillary central incisors (Fig. 4) [19].

Management

Thorough surgical curettage is the treatment of choice for symptomatic lesions or lesions

measuring more than 6 mm in diameter. Recurrence after surgical removal is reported to

Fig. 3. Calcified stylohyoid ligament.


be approximately 2% [19]. Several other cystic lesions may mimic a nasopalatine duct cyst.

Differential diagnosis includes an apical periodontal cyst, lateral periodontal cyst, and odonto-

genic keratocyst [20].

INFLAMMATORY DISEASES

Submandibular salivary gland cortical defect

Frequency/incidence

In 1942, Stafne first described 34 cases of this radiographic abnormality just anterior to the

angle of the mandible [21]. The prevalence rate has been reported to be approximately 0.05%,

with a slight male predominance [22].

Fig. 4. Nasopalatine duct cyst.


Signs and symptoms

This defect usually is asymptomatic and diagnosed on routine panoramic radiograph. When

symptoms occur, they consist of pain and swelling in the area of the submandibular gland.

There is no cortical expansion.


The cause of this cortical defect is unknown; however, various causes have been proposed, in-

cluding stress alteration, pressure atrophy from an inflamed gland, and a congenital defect [22].

The contents of the defect contain submandibular salivary gland elements, fat, and connective

tissue [23].


The panoramic radiograph is the initial screening film of choice. A lateral jaw film also can

detect the defect, and the diagnosis can be confirmed with CT, MRI, and a sialogram of the sub-

mandibular gland that shows salivary gland contents in the cortical depression or defect.

Image hallmarks

The classic presentation is a well-defined radiolucency near the angle of the mandible below

the inferior alveolar canal (Fig. 5). Most of these defects exhibit a hyperostotic border, and mostcases are unilateral. A similar lingual cortical defect can be associated with the sublingual gland,

although it is quite rare [24].

Management

There is no treatment for the cortical defect; however, a symptomatic submandibular gland

may require removal.

Periapical inflammatory disease

Frequency/incidence

Inflammatory disease of pulp with periapical bone involvement is common, with incidence

rates of 40% to 70% [25,26]. The most common location for periapical involvement is the max-

illary anterior region, followed by posterior maxilla, the posterior mandible, and the anterior

mandible [27].

Signs and symptoms

Patients with periapical inflammatory disease may be asymptomatic or present with pain,

swelling, drainage, and possibly fever and regional lymphadenopathy. The associated teeth alsomay be painful and tender to palpation and percussion. The involved teeth are nonvital.


Inflammatory periapical bone disease is initiated by the presence of micro-organisms in the

apical portion of the root canal of the involved tooth [25]. The infection and resultant inflam-

Fig. 5. Submandibular salivary gland defect.


matory response may spread to periapical bone, producing a variety of pathologic conditions,

including inflamed granulation tissue (periapical granuloma, chronic apical periodontitis),

abscess, and apical periodontal cyst (radicular cyst). The development of inflamed granulation

tissue or abscess depends on the virulence of the involved organisms and extent of the infection.

Periapical granulation tissue may continue to destroy bone and ultimately destroy cortical bone.

Fistula formation may occur. An abscess may perforate through cortical plates and create a softtissue space infection, which may create significant morbidity. Activation of residual odonto-

genic epithelium in the periodontal membrane may result in cyst formation. The cyst may ex-

pand and destroy a significant amount of bone. The cyst may be asymptomatic, or the

patient may complain of pain. In a review of 256 periapical lesions, Nair et al found that the

majority (55%) were granulomas and the remaining lesions (45%) were periapical cysts or ab-

scesses [25].


The panoramic radiograph is the initial screening film of choice, followed by periapical radio-

graphs for further delineation of the lesion.

Image hallmarks

The classic presentation is a radiolucency at the apex of a nonvital tooth (Fig. 6). The size and

extent of the lesion varies considerably, with extension laterally and inferiorly from the apex.

A periapical abscess may show only minimal widening of the periodontal membrane of the

involved tooth.

Management

Treatment for periapical inflammatory disease involves either extraction of the involved

tooth or root canal therapy with the appropriate use of antibiotics if the clinical situation war-

rants it. In a follow-up study after root canal treatment, approximately 90% of the lesions

resolved and were not detectable on radiographs [28]. The treatment for unresolved lesions

is surgical removal of the involved tissue and submission of the tissue for microscopic

examination. The distinction between periapical granuloma and apical periodontal cyst can onlybe made by microscopic examination [29].

Fig. 6. Periapical inflammatory disease.


Periodontal disease

Frequency/incidence

Periodontal disease is the leading cause of tooth loss in patients over the age of 35 years.

There is an increased prevalence associated with increased age, diabetes, smoking, and limited

oral hygiene [30]. To some degree, periodontal disease affects most individuals at some pointin their lifetime. Although periodontitis typically is a disease of adulthood, aggressive forms,

termed early-onset periodontitis, may occur in children [31].

Signs and symptoms

The typical sign of periodontal disease is erythematous and edematous gingiva that bleeds

with tissue manipulation. The normal stippling is not present and the gingiva also may be

blunted or apically positioned, depending on the degree of tissue involvement [32]. Patients

may report bleeding with brushing and gingival pain, although these are not consistent symp-toms.


Periodontal disease primarily is caused by bacteria that colonize the gingival crevice. The re-

sultant bacterial products and inflammation ultimately cause destruction of supporting alveolar

bone, which leads to loss of bone support for the teeth. Gingival inflammation and periodontal

bone loss may be localized to several teeth or generalized. Tissue pockets of more than 4 mm are

indicative of an active disease process.


The panoramic radiograph is an excellent initial screening tool and is followed by periapical

radiographs, which better define the amount of alveolar bone loss.

Image hallmarks

Gingival inflammation usually does not show alveolar bone loss. When the inflammatory

response involves alveolar bone, gradual destruction of the interdental bone takes place. Theamount of loss of bone that supports the teeth indicates the severity of the disease process

(Fig. 7).

Management

Treatment depends on the severity of the symptoms and tissue destruction. It consists of a

combination of oral hygiene procedures performed by the patient, mechanical debridement, sur-

gical removal of diseased tissue, and topical antimicrobial agents.

Fig. 7. Periodontal disease.


Osteomyelitis

Frequency/incidence

Osteomyelitis of the jaws was once a frequently encountered disease and was difficult to treat.Now it is much less common because of the improvement in dental and medical health care and

the use of antibiotics [33]. Osteomyelitis is more common in the mandible because of its relative

avascularity when compared with the maxilla.

Signs and symptoms

Patients often present with fever, malaise, edema of the overlying soft tissue, lymphadenop-

athy, purulent discharge, pain, and leukocytosis [34].


Osteomyelitis is an infectious process within the marrow spaces of bone. In the face, the

angle and body of the mandible is the most commonly infected site. Most cases are the result

of a bacterial dental infection. Infected mandibular fractures are the second most common cause

of osteomyelitis [35]. Hematogenous spread also is responsible for cases of facial osteomyelitis.

The cases may be acute or chronic and suppurative or nonsuppurative in nature. Diagnosis is

based on clinical, histopathologic, and laboratory studies.


The panoramic radiograph serves as an initial screening tool. In many cases, CT bone scinto-

grams and MRI are superior to conventional radiographs in delineating the extent of the infec-

tious process. Bone scintography studies with technetium 99 are abnormal in 90% to 95% of

patients with osteomyelitis [34].

Image hallmarks

In the early stages, conventional radiographic images may fail to show any abnormalities;however, areas of ill-defined radiolucencies with or without radiopaque sequestrum and reactive

bone soon develop. The radiographic changes may exhibit a mottled or ‘‘moth-eaten’’ pattern

and mimic malignancy (Fig. 8). The diagnosis of osteomyelitis is based on clinical and radio-

graphic findings.

Fig. 8. Osteomyelitis. (Courtesy of Dr. Jason Ford, Lexington, KY.)


Management

Treatment consists of prompt aggressive surgical debridement of all infected bone down to

healthy bleeding tissue, followed by long-term intravenous or oral antibiotics for 6 to 12 weeks

with high-dose aqueous penicillin G (12–20 million U/day) or clindamycin (2700 mg/day) if thepatient is allergic to penicillin [36]. The patient must be closely followed clinically and radio-

graphically for resolution of the infection. Bony defects that result from the infection may

require further surgical procedures.

Proliferative periostitis (periostitis ossificans)

Frequency/incidence

Proliferative periostitis is a relatively rare, specific type of chronic osteomyelitis that occurs

almost exclusively in children and young adults [37]. The average age of onset is 11 years with

a male-to-female ratio of 1.4 to 1 [38].

Signs and symptoms

Patients most commonly present with symptoms related to their primary infection and a

painless swelling of bone of the affected area. The most common location is the posterior bodyof the mandible with an associated carious molar or premolar. The swelling may be of insidious

onset with only minimal pain over the involved area [39].


In most cases, the infected focus resulting in the periosteal hyperplasia represents a carious

tooth, periodontal disease, or an infected extraction site. There have been reports of prolifera-

tive periostitis resulting from an infected dentigerous cyst [40].


Panoramic and lateral oblique radiographs are appropriate films to establish the diagnosis. Ifthese images do not show the characteristic changes, occlusal and posteroanterior radiographs

may be helpful.

Fig. 9. Proliferative periostitis (periostitis ossificans). (Courtesy of Dr. Dean White, Lexington, KY.)


Image hallmarks

The classic radiographic appearance shows reduplication of cortical bone with a lamellar or

layering effect (‘‘onionskin’’ appearance) stimulated by the underlying inflammatory process

(Fig. 9) [41].

Management

Treatment involves elimination of the source of infection. The cortical enlargement usually

undergoes resolutionwithin 6 to 12months. The presence of proliferative periostitis in the absence

of an inflammatory process requires biopsy of the involved area because processes such as Ewing

sarcoma, Langerhans cell histiocytosis, and metastatic disease can induce this reaction.

Antral pseudocyst

Frequency/incidence

The antral pseudocyst is a relatively common finding on routine panoramic radiographs [42].

Reports indicate that 1.5% to 10%of the population have these on routine radiographic evaluation

[43].

Signs and symptoms

Patients are usually asymptomatic unless a localized infection is present [44]. These latter pa-

tients exhibit symptoms ofmaxillary sinusitis including fever, nasal discharge, headache, and pain.


The antral pseudocyst represents an accumulation of fluid between antral mucosa and the

floor of the sinus. The cause is unknown but some cases may represent the extension of an inflam-

matory exudate from an infected maxillary tooth. The terms sinus mucocele and retention cyst

have been used for this entity; however, there is no accumulation of mucous or true cyst lining

in these lesions, and they should not be confused with the other, more aggressive lesions.

Fig. 10. Antral pseudocyst. (Courtesy of Dr. Dan Trinler, Lexington, KY.)



The panoramic radiograph is the diagnostic film of choice. A water’s view image and CT may

be useful if the diagnosis is unclear on panoramic radiograph.

Image hallmarks

The classic radiographic presentation is a ‘‘domed-shaped,’’ finely radiopaque lesion with its

base on the antral floor (Fig. 10). In rare instances, the entire sinus may be involved [45]; however,other space-occupying lesions of the sinus must be ruled out when it appears in this fashion.

Management

The lesion often regresses on its own and no treatment is necessary in most cases. If symptomsare present, either transantral or endoscopic techniques may be used for removal of the lesion [42].

Sialolith

Frequency/incidence

Salivary calculi (sialoliths) are a common cause of salivary gland dysfunction and may

occur in any of the salivary glands and at almost any age. They occur most commonly in the

submandibular gland duct (83%) and involve the parotid gland duct in 10% of cases. Minor

salivary gland duct and sublingual gland involvement represents the remaining 7% of cases

[46]. Occasionally, the salivary gland itself may be involved. The incidence of sialolithiasis

is approximately 1% in the general population [47].

Signs and symptoms

Some calculi remain asymptomatic; however, most calculi obstruct salivary flow to the point

that the involved gland eventually becomes enlarged and painful. The gland often becomes tense

and painful during or after ameal, which has stimulated the gland to produce and secrete saliva. A

palpable mass may be present depending on the location of the stone within the duct, and at-

tempts to express saliva from the involved ductmay produceminimal or no flow. These symptomsare primarily related to the submandibular and parotid gland systems. Minor gland sialolithiasis

usually manifests as a small nodular mass with possible localized tenderness. If the involved gland

has become secondarily infected, purulent drainage may be seen at the meatus of the duct.


The mechanism behind the development of salivary calculi is not well understood but has

been attributed to mucous stasis within a duct followed by the deposition of calcium salts in

Fig. 11. Sialolith. (Courtesy of Dr. Denise Clarke, Port Angeles, WA.)


a nidus, leading to the development of a calcified mass. In most cases, the sialolith develops

within the duct of the affected gland. Approximately 90% of submandibular stones are situated

in the distal portion of the Wharton duct or at the hilum [48].


The panoramic radiograph is an excellent screening film to detect submandibular and parotid

calculi. This image may be coupled with an occlusal radiograph to determine the location of the

sialolith in the involved duct.

Image hallmarks

Sialoliths appear as radiopaque, ovoid to linear structures often superimposed on normal

radiographic anatomy (Fig. 11). They rarely develop in the gland itself.

Management

Treatment usually involves surgical removal of the sialolith from the duct; however, other mo-

dalities of treatment include laser therapy, extracorporeal electromagnetic shock-wave lithotripsy

and catheter retrieval under fluoroscopy [49]. If chronic sialadenitis is present, the entire gland usu-

ally requires removal. Appropriate antibiotic therapy is indicated if purulent drainage is present.

LOCALIZED METABOLIC DISORDERS

Idiopathic osteosclerosis

Frequency/incidence

The incidence of osteosclerosis of the jaws is 4% to 31% [50]. Approximately 90% of osteo-

sclerosis cases occur in the posterior mandible, with an age predilection between 20 to 40 years.

Osteosclerosis shows equal sex distribution [50–52].

Fig. 12. Radiograph showing osteosclerosis.


Signs and symptoms

Osteosclerosis is an asymptomatic, localized area of increased density of bone without expan-

sion, which is discovered during routine radiographic examination.


The cause of idiopathic osteosclerosis is unknown. It is not associated with inflammatory and

neoplastic processes [50–52]. It is distinguished from condensing osteitis, which has an inflam-

matory origin.


Osteosclerosis is seen on panoramic and periapical radiographs.

Image hallmarks

Osteosclerosis usually is seen as a single, well-defined, homogeneous radiopacity that lacks a

radiolucent rim (Fig. 12) [50,52,53]. It can be circular to ovoid to linear in shape, and the size

ranges from several millimeters to actual diffuse areas of involvement. It typically is seenbetween teeth, at the apices of teeth, and below tooth-bearing areas. Root resorption occurs

in approximately 10% of cases [51].

Management

Once the diagnosis of idiopathic osteosclerosis is made, no treatment is required. Care should

be taken to rule out soft tissue calcification, such as a sialolith, which is superimposed on the

image, and an exostosis.

Osseous dysplasia (cemeto-osseous dysplasia)

Frequency/incidence

Osseous dysplasia represents a reactive process of the jaws, which is subdivided into three,

sometimes overlapping, categories [54–56]. Periapical cemental dysplasia overwhelmingly is seen

in African American women aged 20 to 40 years and involves the periapical region of the ante-rior mandibular teeth [54,56,57]. Focal osseous dysplasia typically is recognized in women in

their 20s and 40s and is found in the posterior mandibular region in tooth-bearing areas [56–

58]. Florid osseous dysplasia represents a process that usually involves the tooth-bearing areas

of multiple quadrants of the jaws and primarily is seen in middle-aged to elderly African Amer-

ican women [56,59].

Signs and symptoms

Periapical cemental dysplasia and focal osseous dysplasia generally are asymptomatic

[54,57,60]. Long-term lesions may exhibit mild cortical expansion. Florid osseous dysplasia usu-

ally is asymptomatic but may show cortical expansion. In addition, some cases of florid osseous

dysplasia will become secondarily inflamed and exhibit fistula formation, loose teeth, and pain.


The cause of osseous dysplasia is unknown [54,57]; however, it is theorized that it represents a

reactive process in which normal bone is replaced by a poorly cellularized bonelike material and

cellular fibrous connective tissue, which originate from periodontal membrane [54,57].


This process is often identified first on periapical radiographs; however, the panoramic radio-

graph is used to show the extent of the abnormality.

Image hallmarks

The radiographic changes depend on the subdivision of the process and the degree of miner-

alization of the proliferation [57]. Periapical cemental dysplasia involves from one to all of the


mandibular anterior teeth. Occasionally, it may also include other teeth. The initial changes are

well-defined radiolucencies at the apices of the involved teeth. The area of bone remodeling may

extend inferiorly and between teeth, and there usually is a progressive mineralization of thelesions. Thus, the changes range from radiolucent to radiolucent/radiopaque to radiopaque with

a radiolucent rim in the final stage. Focal osseous dysplasia represents a solitary lesion associ-

ated with the apex or lateral surface of the root of the involved tooth, and it will demonstrate the

same maturation pattern [56,57]. The florid variant exhibits the same maturation pattern as the

former two categories but will involve multiple teeth and usually multiple quadrants of the jaws

(Fig. 13) [55,56]. The alterations may extend beyond tooth-bearing areas and persistent radio-

lucencies may be present that represent idiopathic bone cavities [55].

Management

Once the diagnosis of osseous dysplasia is made, the patient can be observed. Florid osseous

dysplasia may require antibiotic therapy and surgical debridement if the process becomes secon-darily infected and undergoes sequestration. Patients with this process must practice sound

oral hygiene to help prevent these complications. Focal osseous dysplasia can mimic central os-

sifying fibroma of bone radiographically, and these two conditions may not even be separated

by microscopic examination. Radiographic changes that support focal osseous dysplasia over

ossifying fibroma include contact of the lesion with the apex and/or lateral aspect of the root

and mineralization of the lesion without an increase in the dimensions of the lesion. If the

two cannot be separated on a radiographic basis, biopsy usually is performed. The ossifying

fibroma usually is a solid structure, whereas focal osseous dysplasia usually is friable andremoved in pieces [54].

Simple bone cyst (idiopathic bone cavity, traumatic bone cyst)

Frequency/incidence

Simple bone cysts primarily occur in the mandible, with a predilection for the anterior man-

dible between the mental foramina [61,62]. It usually affects individuals in their teens and 20swith near equal sex distribution [62–65].

Fig. 13. Florid osseous dysplasia.


Signs and symptoms

Simple bone cysts usually are asymptomatic [64], but expansion may occur. Some patients

give a history of previous trauma to the area and may complain of mild pain and tenderness

in the area [64].


It is theorized that simple bone cysts occur secondarily to intraosseous hemorrhage in which

the normal repair mechanism is disrupted, resulting in the defect [61]. The source of hemorrhage

may be trauma, focal degeneration of connective tissue, or idiopathic [61,62,64].


Simple bone cysts often are noted on routine panoramic radiographs, the film most utilized to

identify odontogenic cysts and neoplasms of the jaws.

Image hallmarks

Simple bone cysts often appear aswell-defined radiolucencies of the anterior andmidbodyof the

mandible (Fig. 14) [61,62,64]. The border adjacent to teeth often extends between their roots, pro-

ducing a scalloped border [61,63]. The radiographic image is not diagnostic for simple bone cyst

alone,andotherodontogenic lesionsandneoplasmsmayexhibitasimilarradiographicappearance.

Management

Management includes exploration and curettage of the bony walls to induce clot formation.

Any soft tissue obtained during the procedure is examined microscopically to rule out a true

odontogenic cyst [61,65]. Follow-up radiographic examinations are needed to ensure that bony

fill takes place.

SYSTEMIC METABOLIC DISORDERS

Osteopetrosis

Frequency/incidence

Osteopetrosis is an extremely rare disorder related to a defect in normal bone remodeling. It

is believed to occur in only 0.005% of the population [66,67]. It has three hereditary forms,

which are variable in severity [68].

Fig. 14. Idiopathic bone cavity.


Signs and symptoms

Patients with the autosomal-recessive infantile form of the disease exhibit anemia and hepa-tosplenomegaly. They are susceptible to infections because of the granulocytopenia and exhibit

enlargement of the jaws. A prominent sign is hypertrophy of the mandible, especially an in-

creased width at the gonial angles [68]. Osteomyelitis is a common complication of tooth extrac-

tion. Symptoms related to cranial nerve compression, such as blindness, facial paralysis and

otologic disorders may develop [69,70]; and pathologic fractures are common. Patients with

the autosomal-dominant adult form may exhibit few signs and symptoms.


Osteopetrosis represents a group of hereditary disorders characterized by a defect in osteo-

clastic activity, which results in increased bone formation at the expense of normal marrow

spaces [66,68]. The affected bone exhibits a decrease in vascularity and reduction or elimination

of hematopoietic marrow. The bones become brittle and are susceptible to fracture and infection[66,68]. The severe type affects children who rarely survive past 2 years of age, whereas the milder

forms primarily affect the skeleton and have a better prognosis [66,68].


The jaw changes are best demonstrated on panoramic radiograph. Other conventional facial

radiographs may also be useful in evaluating the extent of the disorder throughout the cranio-

maxillofacial skeleton.

Image hallmarks

Radiographic images of the process show loss of normal medullary trabecular pattern with a

generalized radiopacity of the affected bone resulting from increased bone density (Fig. 15). Thedistinction between cortical and medullary bone becomes nonexistent as the medullary spaces

are obliterated [66,68,71].

Management

Patients with osteopetrosis are highly susceptible to the development of osteomyelitis. Pre-

vention plays an important role in managing a patient with this disease. Emphasis is placed

on excellent oral hygiene and routine dental prophylaxis. Endodontic therapy is encouraged

over dental extraction to avoid excessive trauma to bone. If debridement is necessary, conserva-

tive bone removal is indicated, with minimal periosteal stripping after limited incisional access

[66,69]. Although therapeutic levels of antibiotics are difficult to achieve in these patients, they

are recommended [66].

Fig. 15. Osteopetrosis. (Courtesy of Dr. Dan Sarasin.)


Cleidocranial dysplasia

Frequency/incidence

Cleidocranial dysplasia is a rare hereditary disorder that affects the cranial bones and forma-tion of the clavicles [72,73]. It exhibits equal sex distribution.

Signs and symptoms

Affected individuals are usually short in stature and exhibit a spectrum of hypermobility of

the shoulders, which results in a characteristic appearance of a long neck with a narrow, pigeon-

shaped chest [73]. These patients also may be brachycephalic and exhibit ocular hypertelorism

and altered tooth eruption [72,73].


Cleidocranial dysplasia is a disorder of bone formation and ossification in which the cause is

unknown.Most cases are autosomal dominant; however, 40%of cases representmutations [72,73].


The characteristic dental abnormalities are demonstrated on the panoramic radiograph. The

anteroposterior (A-P) chest radiograph will show the degree to which the clavicles are affected.

Image hallmarks

The characteristic findings on panoramic radiograph are retained deciduous teeth, multiple

impacted teeth, and supernumerary teeth, which may be impacted (Fig. 16). A nasoalveolar cleft

also may be observed. A-P chest films may show the degree of malformation of the clavicles.

Management

Treatment of this disorder is challenging and complex, requiring a multidisciplinary ap-

proach. The basic principles include removing any barriers to the eruption of permanent teeth

[74–76]. This requires timely removal of deciduous teeth and bone with maintenance of space for

future eruption [74,75]. Success is dependent on the formation of the teeth, which may be dam-

Fig. 16. Cleidocranial dysplasia.


aged during surgical exposure, root development, and retention. These patients often require

orthognathic surgery to correct skeletal malformation resulting from hypoplastic maxilla and

hyperplastic mandible. Alternatives for tooth replacement if the permanent teeth are not

positioned and retained include tooth transplantation, dental implants, and dental prostheses

[74–76].

Paget disease

Frequency/incidence

Paget disease is a rare disorder of bone metabolism, which results in the alteration of normal

bone deposition and resorption [77]. The disorder predominantly affects individuals in their 40s

and 50s, with an increased prevalence in men [78–80].

Signs and symptoms

The disease is associated with progressive enlargement of the affected bone. Enlargement ofthe jaws results in changes in occlusion, spacing of teeth, and facial deformity [81]. It may also

cause pain in the affected bone, and multiple bones may be affected. Patients may exhibit neuro-

logic complications, such as visual disturbances and hearing loss, when there is craniofacial

bone involvement.


The cause of the alteration in bone remodeling is unknown [81]. Inflammation and endocrine

and genetic factors have been considered but not substantiated.


The panoramic radiograph is an excellent imaging method to reveal involvement of the jaws

with Paget disease.

Image hallmarks

The characteristic changes of the jaws in Paget disease are seen as areas of radiopacity sur-

rounded by areas of radiolucency (Fig. 17). The areas tend to coalesce and become more radio-

paque. They often exhibit a poorly defined hazy periphery, which is described as a ‘‘cotton

wool’’ appearance. The teeth may exhibit hypercementosis, and there is an increase in interden-

tal spacing [81]. Florid osseous dysplasia may appear in a similar fashion.

Fig. 17. Paget disease. (Courtesy of Dr. Mark McIlwain, Sheffield, AL.)


Management

Medical treatment consists of the alleviation of bone pain and the use of biphosphates to re-

duce progression of the disease by inhibiting osteoclastic activity [77,82]. In patients with facial

disfigurement, recontouring procedures may be performed [77,83]. Patients with advanced in-volvement of the jaws are susceptible to the development of osteomyelitis, giant cell tumor,

and sarcomas [83].

Cherubism

Frequency/incidence

Cherubism is a rare familial disorder that affects children between the ages of 14 months to 20years, with an increased prevalence in boys [84–86]. Isolated cases have been reported, indicating

the possibility of a spontaneous mutation [85,86].

Signs and symptoms

Cherubism is characterized by asymptomatic, bilateral expansion of the mandible, resulting

in the classic picture of fullness of the cheeks. Involvement of the maxilla results in increasedexposure of sclera, giving the appearance of an ‘‘upward gaze’’ to the eyes [84,86,87].


Most cases (80%) are autosomal dominant, affecting 100% of boys and 50% to 70% of

girls [84–86]. The remaining 20% of cases represent spontaneous mutations [84,85,88]. The

enlargement of the jaws is secondary to space-occupying lesions, which microscopically resemble

central giant cell granuloma.


The maxillofacial lesions associated with cherubism are best visualized by panoramic radio-graph.

Image hallmarks

The disorder is characterized by diffuse multilocular radiolucencies of the posterior mandible

and maxilla, with the mandible being involved more frequently than the maxilla (Fig. 18)[84,87,89]. These lesions may alter tooth-eruption patterns, formation of teeth, and displace

the inferior alveolar canal [85].

Fig. 18. Cherubism. (Courtesy of Dr. Denver Tackett, McDowell, KY.)


Management

Cherubism is a self-limiting disorder after the second decade of life. Excess deformity may

require recontouring but this is best postponed as long as possible because postsurgical regrowth

has been reported [84,90].

Fibrous dysplasia of bone

Frequency/incidence

Fibrous dysplasia of bone is a rare proliferative condition that affects the craniofacial skele-

ton and other bones of the body. There are two main patterns: monostotic, which represents

single-bone involvement, and polyostotic, which involves multiple bones. The skull and the jaws

represent the most commonly affected bones; however, the ribs and long bones also are involved

[56,91]. This condition typically develops in the first two decades of life; the monostotic form is

more common [56]. Fibrous dysplasia of bone is a component of McCune-Albright syndrome in

which the affected individual exhibits polyostotic fibrous dysplasia, endocrine abnormalities,

and cafe-au-lait skin pigmentation [56]. Ninety-five percent of individuals with McCune-Albright syndrome are female [56,91].

Signs and symptoms

Fibrous dysplasia of bone is an asymptomatic process that is characterized by expansion ofthe affected bone [56,92].


This disorder is believed to result from a sporadic mutation in the GNAS1 gene postzygo-

tically in a somatic cell [93]. The resulting clinical manifestations, whether McCune-Albright

syndrome or fibrous dysplasia, depend on the size of the embryonic cell mass when the mutation

occurs and where in the cell mass it develops. The earlier the mutation occurs within the embry-

onic tissue, the more likely the chances of the multisystem disorder developing.


The changes of fibrous dysplasia of the jaws are best depicted on panoramic radiograph. Lat-

eral skull and occlusal and periapical radiographs also are of help in demonstrating the charac-

teristic findings. CT is helpful in determining the extent of the process, especially when multiple

bones of the craniofacial complex are involved.

Fig. 19. Fibrous dysplasia of bone. (Courtesy of Dr. Richard Lee, Findlay, OH.)


Image hallmarks

The most characteristic change of fibrous dysplasia of the jaws is a finely radiopaque lesion

that blends with normal surrounding bone (Fig. 19). On fine-grain films, such as periapical ra-

diographs, the lesion exhibits a finely trabecular pattern, which has been termed ‘‘ground glass’’in appearance [56,92]. Some cases, however, exhibit a multilocular or mottled appearance.

Management

The treatment of fibrous dysplasia of the jaws is variable. Most cases tend to stabilize as

patients reach skeletal maturity [56], and mild cases may not require treatment. Patients with

significant cosmetic and/or functional deformities may require one or more surgical reduc-

tion procedures. In some patients, there may be continued enlargement of the affected bone

in adulthood. Regrowth of the lesion after recontouring is variable, with 25% to 50% of patients

exhibiting some postoperative expansion [56,94].

Gardner syndrome

Frequency/incidence

Gardner syndrome is a rare adenomatous polyposis syndrome that is characterized by familial

polyposis, desmoid tumors, epidermoidcysts, anddentaland skeletalabnormalities [95,96].Themean

age of diagnosis is 25 years; however, onset of symptoms may range from 2 to 70 years of age [95].

Gardner syndrome has been reported to occur in between 1 to 8300 and 1 to 16,000 births [95,97].

Signs and symptoms

The extracolonic signs and symptoms are most often recognized first. These include multipleepidermoid cysts, impacted teeth, exophytic hard tissue masses of the mandible, and retinal pig-

mented lesions [96].


Gardner syndrome is an autosomal-dominant disorder with close to 100% penetrance

[95,96,98]. The expression of the syndrome is variable. Nearly one third of cases occur sponta-

neously [95,96]. A gene on chromosome 5 has been identified as being associated with the devel-

opment of the disorder [99].

Fig. 20. Gardner syndrome. (Courtesy of Dr. Edyee Sturgill, Bowling Green, KY.)



The dental and jaw changes associated with the syndrome are best identified on a panoramic

radiograph.

Image hallmarks

The changes seen on radiographs consist of multiple impacted supernumerary and regular

teeth, osteosclerotic areas, and exophytic sclerotic masses of cortical bone, usually seen at the

angles of the mandible and termed osteomas (Fig. 20).

Management

Gardner syndrome is a serious condition that requires early intervention because untreated

patients will develop colorectal adenocarcinoma [95,96]. In women, there also is an increased

risk of developing thyroid carcinoma [96]. The impacted teeth may have to be removed because

of development of odontogenic cysts, and the exophytic osteomas may be removed for cosmeticand functional problems.

Hyperparathyroidism

Frequency/incidence

Hyperparathyroidism ranks third among the incidence of endocrine disorders behind dia-

betes mellitus and hyperthyroidism. It occurs in 30 of every 100,000 patients [100,101]. This

disorder may occur at any age but it predominantly affects those in their 40s and 50s, with

a female-to-male ratio of 3 to 1 [100,101].

Signs and symptoms

Hyperparathyroidism often is asymptomatic [100]; however, some patients will complain of

or exhibit a variety of symptoms including the following: mental depression, confusion, leth-

argy, muscle weakness, nausea and vomiting, peptic ulceration, renal calculi, anorexia, and skel-

etal demineralization [102,103]. The signs and symptoms may be vague and nonspecific, and the

disease may elude diagnosis for some time.


Hyperparathyroidism classically is divided into primary and secondary forms. The most com-

mon cause of the primary form is a parathyroid adenoma that secretes parathyroid hormone.

The excess parathormone results in a derangement of calcium, phosphate, and bone metabol-

ism. This process has been linked to rearrangements of segments of chromosome 11, thus allow-

ing for overexpression of a regulatory protein [100]. Inactivation of tumor suppressor genes andmutations of calcium-sensing receptor genes also have been postulated [100]. The secondary

form is caused by gland hyperplasia in response to low-serum calcium levels resulting from renal

failure or intestinal malabsorption. This disorder may result in alterations of bone because of

the increased levels of parathormone, which stimulates increased bone resorption [100].


Panoramic and periapical radiographs are the ideal imaging methods to evaluate jaw changes

that may occur with the disorder.

Image hallmarks

In primary hyperparathyroidism, the jaw changes may occur as unilocular or multilocular ra-

diolucencies referred to as ‘‘brown tumors’’ [100]. Microscopically, they are identical to central

giant cell granuloma. In addition, the changes may consist of a generalized alteration of medul-

lary bone that exhibits a ‘‘ground glass’’ appearance; however, this change is more commonly

seen in secondary hyperparathyroidism (Fig. 21). This change usually is accompanied by a lossof lamina dura. Distinct lytic lesions are less common in secondary hyperparathyroidism.


Management

Primary hyperparathyroidism is treated with parathyroidectomy with a 90% success rate

[100]. Those patients refractory to or not surgical candidates are managed medically with oral-

phosphate supplements, estrogen therapy, and calmodulin to decrease serum calcium [100]. The

secondary form is treated by correcting the underlying medical condition [100].

DEVELOPMENTAL ODONTOGENIC CYSTS

Dentigerous cyst

Frequency/incidence

Dentigerous cysts are the second most common odontogenic cyst and account for 24% oftrue jaw cysts [104]. The frequency of dentigerous cysts is 1.44 per 100 unerupted teeth [105].

The mandibular third molars are the most commonly involved teeth.

Signs and symptoms

Most patients with dentigerous cysts are asymptomatic. Large cysts may cause expansion of

bone in the involved area.


The dentigerous cyst represents a pathologic cystic cavity lined by follicular epithelium that

develops around the crown of an impacted tooth [106]. It is capable of significant enlargement

and destruction of bone. The cause of its development is unknown.


The panoramic radiograph is an ideal imaging method to detect dentigerous cysts. The cysts

also may be detected with periapical radiographs.

Image hallmarks

The radiographic presentation of the dentigerous cyst is a well-circumscribed, unilocular ra-

diolucency around the crown of an impacted tooth (Fig. 22). The cyst measures from 3 to 5 mm

to many centimeters [107]. It typically affects permanent impacted teeth; but in rare incidences,

Fig. 21. Hyperparathyroidism.


deciduous teeth may be involved. The cyst is usually an isolated lesion, but several teeth may beaffected. Multiple dentigerous cysts may occur without the characteristic features of the nevoid

basal cell carcinoma syndrome [108].

Management

The treatment of dentigerous cysts is complete enucleation of the cyst and removal of the in-

volved impacted tooth. The cystic tissue is submitted for microscopic examination to rule out

other aggressive odontogenic lesions.

Odontogenic keratocyst

Frequency/incidence

Odontogenic keratocysts make up approximately 12% of odontogenic cysts [109]. The man-

dible is involved in 65% of the cases, and the molar region is the most common location [109].

There is an equal sex distribution. A significant recurrence rate has been reported [110,111], andit has been reported that 8.8% to 12% of patients with odontogenic keratocysts have the nevoid

basal cell carcinoma syndrome [110].

Signs and symptoms

Most patients with odontogenic keratocysts are asymptomatic; however, some may exhibit

pain and swelling of the involved area of the jaw.


Odontogenic keratocysts most likely develop from remnants of dental lamina. The cause is

unknown.


The panoramic radiograph is an excellent imaging method to demonstrate the odontogenic

keratocyst, especially in the posterior regions of the jaws. Periapical radiographs also are ableto detect the cyst when it develops in tooth-bearing areas.

Image hallmarks

Odontogenic keratocysts typically present as unilocular radiolucencies; however, they also

may be multilocular, especially large keratocysts (Fig. 23). Keratocysts are often associated

Fig. 22. Dentigerous cyst.


with impacted teeth and resemble dentigerous cysts radiographically. They also can develop inbetween teeth (lateral periodontal cyst position) and in place of a tooth. In addition, keratocysts

may mimic nasopalatine duct cysts [109] and apical periodontal cysts. In some cases, a curved

scalloped border may be present [112].

Management

Treatment of odontogenic keratocysts is complete removal, ranging from enucleation and

curettage to en bloc resection. The treatment depends on many factors, including position

and extent of the lesion and patient cooperation. No single treatment is applied to all patients.

Recurrent lesions often require more aggressive therapy [113].

Nevoid basal cell carcinoma syndrome

Frequency/incidence

The incidence of the syndrome is 1 in 57,000 to 1 in 164,000 births [114].

Signs and symptoms

Up to 75% of patients have odontogenic keratocysts of the jaws, and these often develop

before the age of 20 [114]. These cysts are situated around the crowns of unerupted teeth and

between teeth. The basal cell carcinomas usually develop during or after puberty; and by the

age of 40, up to 97% of affected persons exhibit these changes. Most patients have palmar

and/or plantar pits. Other potential abnormalities include frontal bossing, hypertelorism, stra-

bismus, palate abnormalities, calcified falx cerebri, and macrocephaly [115].


The nevoid basal cell carcinoma syndrome is an autosomal dominant disorder, and an abnor-

mality of chromosome 9 has been identified in those patients who have the syndrome [116]. Itsexpression is thought to be caused by a modification of a tumor suppression gene.


The panoramic radiograph is the image of choice to identify the cystic lesions of the jaws.

Fig. 23. Odontogenic keratocyst.


Image hallmarks

The jaw changes represent single or multiple unilocular radiolucencies, usually situated

around the crowns of unerupted teeth and between the roots of teeth (Fig. 24).

Management

The radiolucent lesions microscopically represent odontogenic keratocysts, and treatment isthe same for those in the non-syndrome patient.

Lateral periodontal cyst

Frequency/incidence

Lateral periodontal cysts are relatively rare, comprising approximately 8% of cysts of the

jaws [117]. The lesion typically is seen in adults and most commonly in the sixth decade of life.

There is no sex predilection [118,119].

Signs and symptoms

The lateral periodontal cyst is asymptomatic and usually discovered on routine radiographs.


Lateral periodontal cysts develop from rests of dental lamina found in the periodontal mem-

brane and interradicular bone. The cause is unknown. The cysts are not associated with an in-flammatory process.


Lateral periodontal cysts are identified on panoramic and periapical radiographs.

Image hallmarks

The lesion typically is viewed as a small, well-circumscribed radiolucency between the rootsof vital teeth (Fig. 25). It may have a sclerotic border [120]. Most lesions occur in the mandib-

ular canine-premolar area and the maxillary incisor to first premolar region [121]. The odonto-

genic keratocyst may give a similar radiographic appearance.

Management

Lateral periodontal cysts are treated by enucleation. Recurrence is rare [122].

Fig. 24. Nevoid basal cell carcinoma syndrome. (From Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and

maxillofacial pathology. 2nd edition. Philadelphia: WB Saunders; 2002.)


Calcifying odontogenic cyst

Frequency/incidence

Calcifying odontogenic cysts are rare and represent 1% to 2% of all odontogenic lesions [123].

They are found in patients of a broad age range, and there is equal sex distribution. The man-

dible and maxilla are almost equally affected, and 65% of cysts occur in the anterior regions ofthe jaws [124].

Signs and symptoms

Most calcifying odontogenic cysts are asymptomatic but enlargement of bone may occur.

The cysts also may develop primarily in the gingiva with no bone involvement.


The cause of calcifying odontogenic cysts is unknown. The cysts most likely develop from

dental lamina.


Calcifying odontogenic cysts are detected on panoramic and periapical radiographs.

Image hallmarks

The radiographic appearance of calcifying odontogenic cysts is variable (Fig. 26). They may

be unilocular or multilocular. The cysts are usually well-outlined and may contain areas of

calcification [125]. They may also develop in association with odontomas, and they are often

associated with impacted or unerupted teeth and found in between teeth.

Fig. 25. Lateral periodontal cyst.


Management

Treatment of calcifying odontogenic cysts is enucleation but they may require more

aggressive therapy depending on the extent of the lesion and the microscopic findings

[126].

ODONTOGENIC NEOPLASMS

Ameloblastoma

Frequency/incidence

Ameloblastomas represent 1% of all oral tumors, and 80% to 85% occur in the mandible.

There is no sex predilection [127]. The average age at diagnosis is 33 years [128].

Signs and symptoms

Ameloblastomas are infiltrating, locally aggressive neoplasms that can destroy bone, per-

forate cortical plates, and cause considerable expansion. They are generally considered to beslowly growing, and there usually is no associated pain [127]. In rare instances, the ameloblas-

toma has metastasized; and in 75% to 80% of cases, the lungs represented the metastatic focus

[129]. Ameloblastomas also may develop outside of bone on the gingiva.

Fig. 26. Calcifying odontogenic cyst. (From Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial

pathology. 2nd edition. Philadelphia: WB Saunders; 2002.)



Ameloblastomas arise from odontogenic epithelium, principally dental lamina, and possibly

dentigerous cyst lining. Peripheral ameloblastomas also may develop from the basal cell layer of

gingival surface epithelium. The cause is unknown.


The image of choice for the detection of ameloblastomas is the panoramic radiograph. The

periapical radiograph may also be used to detect ameloblastomas and other jaw proliferations.CT also is used to determine the extent of the lesion.

Image hallmarks

Ameloblastomas have a variable radiographic appearance. The classic description is that of a

multilocular, well-defined radiolucency of the posterior mandible in the molar-ramus region

(Fig. 27) [130]. Ameloblastomas also may be unilocular, and they occur in the anterior mandible

and maxilla. They may be associated with impacted teeth and may occur in between teeth.

Management

Complete surgical excision is the treatment for ameloblastomas. Reported treatment ranges

from curettage to radical resection depending on the type of ameloblastoma, its location,

and the extent of the lesion. More radical treatment may lower the recurrence rate [131], which

varies greatly in published reports [127]. Fifty percent of all recurrences occur within 5 years of

surgery [127].

Calcifying epithelial odontogenic tumor

Frequency/incidence

Calcifying epithelial odontogenic tumors are rare, representing 1% of all odontogenic tumors

[132]. Most of the tumors occur in men and women from the ages of 20 to 40 years. There is

equal sex distribution [133]. The tumors occur twice as often in the mandible than the maxilla.Many of the reported cases have developed in association with impacted teeth.

Fig. 27. Cropped radiograph of an ameloblastoma. (Courtesy of Dr. Arthur Gonty, Lexington, KY.)


Signs and symptoms

Most cases of calcifying epithelial odontogenic tumors are asymptomatic. They may causecortical expansion, and may develop in the gingiva as an asymptomatic swelling.


The origin of calcifying epithelial odontogenic tumors is believed to be reduced enamel epi-

thelium or stratum intermedium [134]. The cause is unknown.


The image of choice for the evaluation of jaw cysts and neoplasms is the panoramic radio-

graph. CT is helpful to determine the extent of the lesion.

Image hallmarks

The radiographic appearance of a calcifying epithelial odontogenic tumor is variable. It may

be unilocular or multilocular and associated with an impacted tooth (Fig. 28). The tumor’s out-line ranges from well circumscribed to irregular, and it may exhibit areas of radiopacity.

Management

The treatment of calcifying epithelial odontogenic tumors is surgical excision. Maxillary

lesions may require more aggressive therapy if vital structures are involved [134]. Recurrences

may develop up to several decades after initial therapy [134].

Adenomatoid odontogenic tumor

Frequency/incidence

Adenomatoid odontogenic tumors are the fifth most common odontogenic tumors, with an

incidence of between 2.2% and 7.1% [135]. They occur most commonly in the second decade of

life, primarily in women [136]. The tumors are most often seen in the anterior regions of the

jaws, usually the maxilla.

Signs and symptoms

Most cases of adenomatoid odontogenic tumor are asymptomatic. The tumors may cause

cortical expansion. They are often discovered on routine radiographic examination or when a

patient is being evaluated for a delay in eruption of a permanent anterior tooth.

Fig. 28. Calcifying epithelial odontogenic tumor. (Courtesy of Dr. Samuel McKenna.)



The tumors most likely arise from dental lamina. The cause is unknown. The tumors have

been described as occurring with other odontogenic neoplasms [137].


The panoramic and periapical radiographs are the images used to detect this tumor.

Image hallmarks

Adenomatoid odontogenic tumors present as well-defined, unilocular radiolucencies (Fig. 29).Most cases are associated with the crown of an unerupted tooth, usually a maxillary cuspid.

They also occur between the roots of anterior teeth. The radiolucency may show a flocculent

pattern of discrete, noncoalescing radiopacities [138].

Management

Treatment of adenomatoid odontogenic tumors is surgical enucleation. The lesion usually is

well encapsulated, and recurrence, even after conservative therapy, is rare to nonexistent [135].

Odontogenic myxoma

Frequency/incidence

Odontogenic myxomas are rare, accounting for 3.1% to 11.8% of all odontogenic tumors

[139]. They involve the mandible more than the maxilla and are most common in men and

women in their teens and 20s. There is a slight female predilection [140].

Signs and symptoms

Most cases of odontogenic myxoma are asymptomatic; however, enlargement of the involved

bone may be present.


Odontogenic myxomas are benign but potentially locally aggressive neoplasms of odonto-

genic ectomesenchyme. Their cause is unknown.


Odontogenic myxomas are best visualized on the panoramic radiograph. Small myxomas

situated between teeth also may be seen on periapical radiographs. CT is helpful in determining

the extent of the lesion.

Fig. 29. Adenomatoid odontogenic tumor. (Courtesy of Dr. William Dobbin, Manchester, NH.)


Image hallmarks

The radiographic appearance of odontogenic myxomas is variable. The classic description is

a circumscribed, multilocular (‘‘soap bubble’’) radiolucency of the body and posterior mandible

(Fig. 30) [141]. They can be unilocular, especially when they occur between teeth, and they may

be associated with the crown of an unerupted tooth.

Management

The treatment of odontogenic myxomas varies from curettage to en bloc resection, depending

on the location and extent of the lesion. Recurrence rates range from 10% to 33% [140].

Odontoma

Frequency/incidence

Odontomas are the most common odontogenic proliferations. Their frequency has been

reported to be 46% to 74% of all odontogenic tumors [139,142]. Most odontomas, however,

represent hamartomas rather than true neoplasms. They usually are found in the first to third

decades of life, and there is an equal sex distribution.

Signs and symptoms

Odontomas usually are asymptomatic; they are found on routine dental radiographs and

when a patient is being evaluated for a delay in eruption of a permanent tooth [143]. In rare

instances, multiple odontomas have been described in systemic abnormalities, such as cleidoc-

ranial dysostosis and Gardner syndrome [144].


Most odontomas represent developmental anomalies and not true neoplasms [145]. The

cause is unknown.


Odontomas are seen on both panoramic and periapical radiographs.

Image hallmarks

Odontomas exhibit a varying radiographic appearance. Compound odontomas are charac-

terized by the formation of tooth-like structures. There may be a peripheral area of radio-

lucency. Complex odontomas are radiopaque and represent a haphazard arrangement of dental

hard and soft tissue (Fig. 31). A radiolucent rim also may be present. Odontomas usually areseen adjacent to the crown of an unerupted tooth and between the roots of teeth [146].

Fig. 30. Odontogenic myxoma. (From Fonseca RJ. Oral and maxillofacial surgery. 1st edition. Philadelphia: WB

Saunders; 2000.)


Management

Treatment of odontomas is conservative surgical removal (enucleation). Recurrences are rare

to nonexistent [147].

Ameloblastic fibroma

Frequency/incidence

Ameloblastic fibromas are rare odontogenic neoplasms, representing 2.5% of all odontogenic

tumors [148]. The average age at the time of diagnosis is 15 years. More than 80% of cases occur

in mandible in the premolar-molar region.

Fig. 31. Odontoma.

Fig. 32. Ameloblastic fibroma. (Courtesy of Dr. Douglas Damm, Lexington, KY.)


Signs and symptoms

Most ameloblastic fibromas are asymptomatic. They may cause expansion of the involved

bone. They are often discovered when a patient is being evaluated for a delay in eruption of

a permanent tooth.


Ameloblastic fibromas are benign, encapsulated odontogenic neoplasms of both odontogenic

epithelium and mesenchyme. Their cause is unknown.


The image of choice for detection is the panoramic radiograph. Periapical radiographs mayalso be used to detect the lesion.

Image hallmarks

The ameloblastic fibroma is usually seen as a unilocular radiolucency associated with thecrown of an unerupted posterior mandibular tooth (Fig. 32) [149]. It often exhibits a sclerotic

border and, at times, may be compartmentalized.

Management

Treatment is enucleation and curettage. Recurrences occasionally have been described and

follow-up is important [150].

Ameloblastic fibro-odontoma

Frequency/incidence

The incidence of ameloblastic fibro-odontomas ranges from 1.7% to 3.1% of all odontogenic

neoplasms [134,151]. They occur most commonly in the posterior regions of the jaws in the first

two decades of life. Eighty-three percent are associated with unerupted teeth [151].

Signs and symptoms

Most ameloblastic fibro-odontomas are asymptomatic. They may be associated with enlarge-

ment of the involved bone, and they often are detected when the patient is evaluated for an un-

erupted tooth.

Fig. 33. Ameloblastic fibro-odontoma. (Courtesy of Dr. Samuel McKenna.)



Ameloblastic fibro-odontomas are neoplasms of odontogenic epithelium and mesenchyme.

They have the capacity to form dental hard tissue [152]. The cause is unknown.


The panoramic radiograph is the image of choice for the detection and evaluation of amelo-

blastic fibro-odontomas.

Image hallmarks

Ameloblastic fibro-odontomas typically appear as mixed radiolucent-radiopaque lesions as-sociated with the crown of one or more unerupted posterior teeth (Fig. 33). They are more com-

mon in the mandible. The affected teeth may be displaced away from the normal tooth-bearing

area [153]. The radiopaque material has the radiodensity of tooth structure.

Management

Treatment is by conservative surgical enucleation or curettage with removal of the associatedunerupted teeth. Maintenance of the teeth may lead to recurrence [151,153].

NONODONTOGENIC NEOPLASMS

Central giant cell granuloma

Frequency/incidence

More than 60% of all central giant cell granulomas occur before the age of 30 years. Twothirds of all cases develop in women, and the mandible is affected approximately 70% of the

time. The lesion affects the anterior portions of the jaws more frequently than the posterior seg-

ments, and it is not uncommon for the lesion to cross the midline of the mandible [154].

Fig. 34. Central giant cell granuloma.


Signs and symptoms

Most central giant cell granulomas are asymptomatic. They may cause expansion and perfo-

ration of bone, and a minority of cases may be associated with pain and paresthesia [155].


The cause of central giant cell granuloma is unknown. There is no consensus that this process

represents a true neoplasm; however, the lesion may exhibit aggressive growth and destroy sig-

nificant bone. The microscopic features are the same as seen in the brown tumor of hyperpar-

athyroidism [154].


The image of choice is the panoramic radiograph. Periapical radiographs may also be used to

detect these lesions, especially those that develop in tooth-bearing areas of the jaws.

Image hallmarks

Most central giant cell granulomas appear as well-defined multilocular radiolucencies (60%)

of the anterior mandible below the apices of involved teeth (Fig. 34). Root resorption and tooth

displacement may occur. The granulomas also may appear unilocular (39%) [154]. They may

develop between teeth and be associated with unerupted teeth.

Management

The usual treatment of central giant cell granuloma is aggressive curettage; the recurrence

rate with this treatment ranges from 15% to 20%. More aggressive lesions may be treated by

resection. Nonsurgical management has been considered recently and has included intralesional

injection of corticosteroids and the systemic use of calcitonin [156].

Ossifying fibroma

Frequency incidence

Ossifying fibromas are most common during the third and fourth decades of life, primarily in

women. Most cases develop in the mandible, but 20% develop in the maxilla [57,157].

Signs and symptoms

Most ossifying fibromas are asymptomatic. Some will exhibit enlargement of the involved

bone [57].

Fig. 35. Ossifying fibroma. (Courtesy of Dr. John Cramer, Corbin, KY.)



Central ossifying fibromas represent true primary neoplasms of bone. The cause is un-

known.


The panoramic radiograph is the image of choice for detecting the lesion. Periapical radio-

graphs may also be used to identify ossifying fibroma.

Image hallmarks

Ossifying fibromas may be either unilocular or multilocular (Fig. 35). They usually are well

defined and may have a sclerotic border. Depending on the degree of mineralization of the

tumor’s connective tissue, the fibromas may appear radiolucent or radiolucent/radiopaque.Displacement of the roots of teeth also may be seen [157,158].

Management

Conservative surgical treatment is the treatment of choice for most ossifying fibromas. Ag-

gressive tumors may need more aggressive therapy. The tumor usually is separated from sur-

rounding normal bone and typically can be removed in a single piece. This is in contrast to

focal osseous dysplasia, a reactive process with a similar radiographic picture, which blends with

surrounding normal bone and is removed in small fragments [57].

Osteoblastoma/cementoblastoma

Frequency/incidence

Osteoblastomas and cemetoblastomas are believed to represent the same neoplastic process.The main difference is that cementoblastomas are attached to the root of an involved tooth and

originate from progenitor cells in the periodontal membrane rather than medullary bone as in

osteoblastomas. Both are rare neoplasms of the jaws. Approximately 70% of osteoblastomas

have been reported to occur in the mandible [159]. They show a mean age of occurrence of

20 years, with a range of 5 to 59 years [159]. Cementoblastomas typically occur before the

age of 30 years, with a range of 6 to 75 years [159]. More than 90% of cases occur in the

molar-premolar region of the jaws, and the mandible is more commonly affected [159].

Signs and symptoms

Most osteoblastomas and cementoblastomas exhibit enlargement of the involved bone at the

time of discovery. Most patients will complain of spontaneous pain. Displacement of teeth may

occur [160,161].


The lesions represent true neoplasms of osteoblasts and cementoblasts. The cause is unknown.


The panoramic radiograph is the image of choice for detection. Periapical radiographs are

helpful in determining whether attachment to an involved tooth may exist, and CT is useful

to determine the extent of the lesion.

Image hallmarks

The osteoblastoma usually appears as a well-circumscribed lesion that exhibits radiolucent

and radiopaque areas (Fig. 36). In some cases, it will not be well delineated from surrounding

bone. It is not continuous with the root surface of involved teeth. The cementoblastoma has a

distinct radiographic appearance. It typically is well defined from surrounding bone, and it ap-pears attached to the root of a tooth. The cementoblastoma usually is a mixed radiolucent/

radiopaque lesion or one that is mostly radiopaque. The periodontal membrane space of the

involved tooth characteristically is continuous with a radiolucent rim that surrounds the lesion

[159,161,162].


Management

Osteoblastomas of the jaws are treated by complete surgical removal, often by curettage. Re-

currence is uncommon. Cementoblastomas are treated by the surgical removal of the affected

tooth and tumor mass. Removal of the mass and only the root portion of the tooth that isinvolved also has been utilized [161,162]. Follow-up information on this technique is not well

established.

Osteosarcoma

Frequency/incidence

Osteosarcomas of all bones in the skeleton affect only 1 in 100,000 persons each year. Osteo-

sarcomas of the jaws account for approximately 5% of all osteosarcomas. Lesions generally oc-

cur in the third decade of the life in the jaws, but osteosarcomas of long bones usually occur in

the second decade of life. Men have a slightly increased incidence, and the mandible and maxilla

are equally affected [163,164].

Signs and symptoms

Cortical expansion and pain are the most common symptoms of an osteosarcoma. Depend-

ing on the location within the jaws, paresthesia and tooth mobility may be present [165,166].


An osteosarcoma is a malignancy of bone-forming cells. The cause is unknown, but there is

an increased incidence in the growth plates of long bones. There also is an association of the

disease with other pathologic processes that involve increased bone remodeling and growthand previous radiation therapy [163,164].


The panoramic radiograph is the image of choice for visualizing the disease. CT is helpful in

determining the extent of the process.

Fig. 36. Osteoblastoma/cementoblastoma. (Courtesy of Dr. Robert Hastings, Campbellsville, KY.)


Image hallmarks

The lesion of osteosarcoma may be radiolucent, mixed radiolucent/radiopaque, or radiopaque

(Fig. 37). It may exhibit a mottled appearance, and the borders are commonly ill defined. The

peripheral borders may exhibit a radiating growth pattern of tumor bone referred to as a ‘‘sun-

burst’’ pattern, which is present in approximately 25% of the cases. Those lesions that arise intooth-bearing areas may involve periodontal membrane and produce a widened space. This is

not an exclusive feature of osteosarcoma because it may be seen with other malignancies

[163,166].

Management

Surgical resection is the treatment of choice for osteosarcomas. Pre- and postoperative che-motherapy and postoperative radiation also are utilized. The survival rate does not appear to

increase with the use of adjunctive chemotherapy as in long bones [163,165,166]. Up to 18%

of the patients will exhibit metastasis, usually to lung. Uncontrolled local recurrence is the main

cause of death in patients with osteoscarcoma of the jaws. Mardinger et al [163] reported a

3-year survival rate of 72% for their patients.

Chondrosarcoma

Frequency/incidence

Chondrosarcomas are rare, malignant neoplasms. They are reported to account for less than

3% of all head and neck tumors. They occur most often in the third to sixth decades of life. Men

show a very slight predilection. There is equal distribution in the mandible and maxilla [167].

Signs and symptoms

The most common symptom of chondrosarcoma of the orofacial structures is a painless swel-

ling or mass. Other symptoms include pain, loose teeth, epistaxis, nasal obstruction, and visualor ocular changes [168].


Chondrosarcoma is a malignancy of cartilage-forming cells. The cause is unknown.

Fig. 37. Osteosarcoma. (Courtesy of Dr. Joseph Finelli, Syracuse, NY.)



The panoramic radiograph is the image of choice for detection. CT scan is used to evaluate

the extent of the tumor.

Image hallmarks

Chondrosarcomas typically appear as ill-defined lesions that may be radiolucent or mixed

radiolucent/radiopaque (Fig. 38). They may also induce widening of the periodontal membrane

space [169].

Management

Surgical resection is the treatment of choice for chondrosarcomas. Chemotherapy and radi-

ation therapy normally are not effective against these neoplasms. The prognosis of chondrosar-

coma of the jaws is poor [167,169].

Ewing sarcoma

Frequency/incidence

Ewing sarcomas are rare, malignant neoplasms that predominantly occur in the first two dec-

ades of life. About two thirds of all reported Ewing sarcomas occur in the lower skeleton. Less

than 1% of cases occur in the facial skeleton. The mandible is more commonly involved than the

maxilla. Sixty-five percent of the tumors occur in males [170].

Signs and symptoms

The most common symptoms are pain and swelling in the affected area. Loosening of teeth

also may occur [170].


Ewing sarcoma is a malignancy of primitive cells, thought to be derived from neuroectoderm

[170]. The cause is unknown.

Fig. 38. Chondrosarcoma. (Courtesy of Dr. Robert Morris, Lexington, KY.)



The image of choice for the identification of Ewing sarcoma is the panoramic radiograph. CT

is helpful to determine the extent of the neoplasm.

Image hallmarks

The typical radiographic pattern is that of an ill-defined radiolucency (Fig. 39). The tumor

may stimulate replication of cortical bone identical to that seen in proliferative periostitis

[171,172].

Management

Management of Ewing sarcoma consists of surgical resection and the use of radiation therapy

and multiple chemotherapeutic agents. With the use of multiple modalities for treatment, the

estimated 5-year survival rate for the tumor at a major treatment institution is 83% [170].

Metastatic neoplasms of the jaws

Frequency/incidence

Metastasis to the jaws is not rare. The most common location is the molar region of the man-

dible [173]. The most common primary sites in women are breast, adrenal gland, colorectal sys-tem, genital organs, and thyroid gland. Breast is the most common organ, representing 30% of

cases [174]. The most common primary sites in men are lung, prostate, kidney, bone, and adre-

nal gland [173]. 30% of cases of jaw metastases represent the initial sign of the cancer. The male-

to-female ratio is 1 to 2 [174].

Signs and symptoms

Signs and symptoms range from mild soreness and pain to facial deformity and numb chinsyndrome [174]. Loose teeth also are a sign.


Metastatic cancer to the oral cavity is believed to result from hematogenous spread from the

primary site.


The panoramic radiograph and periapical films are the images of choice for detecting meta-

stasis to the jaws.

Fig. 39. Ewing sarcoma. (From Fonseca RJ. Oral and maxillofacial surgery. 1st edition. Philadelphia: WB Saunders;

2000.)


Image hallmarks

The typical radiographic presentation of jaw metastasis is that of a radiolucency that is either

poorly defined or well outlined (Fig. 40). Certain cancers, such as breast and prostate, may in-

duce new bone formation and create a mixed radiolucent/radiopaque lesion [175].

Management

Metastasis to the jaws indicates that the therapy for the primary cancer has failed to control

the disease. Treatment consists of modalities used for disseminated primary disease. Generally,

patients diagnosed with metastatic disease of the jaws do not survive more than 1 year [173].

HEMATOLOGIC/LYMPHORETICULAR DISEASES

Neutropenia

Frequency/incidence

Neutropenia is a rare, pathologic reduction of neutrophils that is subdivided into congenital(hereditary) and acquired forms. The congenital form commonly manifests in infants and ado-

lescents. The acquired form more commonly occurs in later life [176].

Signs and symptoms

Patients with neutropenia exhibit an increased incidence of bacterial infections. They exhibit

fever, malaise, weakness, and symptoms of an infection at a specific anatomic site. In the oral cav-

ity, patients typically develop aphthous-like ulcers, gingivitis, and periodontal bone loss [176,177].


Neutropenia is defined as a circulating neutrophil count below 1500 mm3. Primary or con-

genital neutropenia usually is the result of a genetic abnormality. Acquired neutropenia may

Fig. 40. Metastatic neoplasms.


result from a variety of causes, including chemical and drug exposure, radiation, and bacterialand viral infections. Because the neutrophil is the primary defense against bacterial infections,

the patient experiences an increased incidence of infections from these agents [176,177]. The

most common organisms are gram-negative bacteria and Staphylococcus aureus.


The image of choice for detection of the radiographic changes are panoramic and periapical

radiographs.

Image hallmarks

The oral radiographic changes of neutropenia are areas of significant periodontal bone loss

(Fig. 41) [177].

Management

The infections that result from neutropenia are treated with appropriate antibiotics. Human

granulocyte colony-stimulating factor has shown promise, and patients are encouraged to main-

tain meticulous oral hygiene to decrease the effects of periodontal bacterial flora [176,177].

Langerhans cell histiocytosis

Frequency/incidence

This is an uncommon disorder of Langerhans histiocytes in which 10% to 20% of all cases

affect the jaws. The mean age of diagnosis of the process in the jaws is reported as 18 years.

The mandible is more often affected than the maxilla, and it is more common in men [178].

Signs and symptoms

Bone lesions are the most common presenting symptoms of Langerhans cell disease [178]. Pa-

tients may present with lymphadenopathy. Infants may exhibit a skin rash and necrotizing areas

of the gingiva and alveolar ridge. Older children and adults also may exhibit changes, including

pain, gingival swelling, tooth mobility, parasthesia, and facial swelling [178,179].

Fig. 41. Neutropenia. (Courtesy of Dr. John Cramer, Corbin, KY.)



Langerhans cell histiocytosis represents a symptom complex characterized by the pathologic

accumulation of histiocytic cells that normally populate epidermis, mucosa, lymph nodes, and

bone marrow and are involved with the presentation of antigens to T lymphocytes. The cause is

unknown. The process is subdivided into three categories but overlap of symptoms exists[180,181]. The categories include acute disseminated, chronic multifocal, and a process that

affects one or multiple bones without soft tissue involvement (eosinophilic granuloma of bone).

The acute disseminated form affects soft tissue, lymph nodes, and visceral organs and

generally does not affect bone. The chronic multifocal form exhibits bone, skin, and visceral

involvement.


The images of choice to detect the jaw lesions of Langerhans cell histiocytosis are panoramic

and periapical radiographs.

Image hallmarks

The jaw lesions of Langerhans cell histiocytosis are characterized by a radiolucency that often

is present in interradicular or periapical bone (Fig. 42). The histiocytosis often mimics an inflam-

matory process [178] and may be poorly defined. Involved teeth may totally lack alveolar bone

support and appear ‘‘floating in soft tissue.’’ Multiple lesions may be present.

Management

Once the microscopic diagnosis of Langerhans cell histiocytosis is established, the patient

must be evaluated for multifocal involvement. Localized jaw lesions usually are treated by cur-

ettage. Low-dose radiation may be used for less accessible bone lesions [178]. The other forms

require systemic therapy, including chemotherapy. Eosinophilic granuloma of the jaws has a

Fig. 42. Langerhans cell histiocytosis. (Courtesy of Dr. James White, Cinncinnati, OH.)


good prognosis, with a reported recurrence rate of 1.6% to 25% [178,179]. Death is rare in the

chronic disseminated form; the acute disseminated form has a poor prognosis [180,181].

Non-Hodgkin lymphoma

Frequency/incidence

Approximately 24% of non-Hodgkin lymphomas develop in extranodal sites. Primary intra-

osseous lymphoma accounts for 5% of extranodal lymphomas, and jaw involvement is rare.

When the oral cavity is involved, the jaws are affected approximately 30% of the time [182,

183,184].

Signs and symptoms

Lymphomas of the head and neck and oral cavity primarily manifest as a soft tissue swelling.

Those that involve the bone of the jaws often are associated with swelling of the involved area,

pain, tooth mobility, and cervical lymphadenopathy [184,185].


Most lymphomas of the jaws are B-cell lymphomas. The cause is unknown. The developmentof lymphomas has been associated with the Epstein-Barr virus and human T-cell lymphoma

virus 1 [186].


Panoramic and periapical radiographs are utilized to detect the change of the jaws associated

with lymphoma. CT, MRI, and bone scintography also are helpful in evaluating the extent of

involvement of the process.

Image hallmarks

Non-Hodgkin lymphoma of the jaws appears as single or multiple areas of ill-defined bone

destruction, which may exhibit areas of reactive bone formation (Fig. 43) [185–187]. These areas

may affect alveolar bone and mimic inflammation.

Management

Oral lymphoma is treated by radiation and/or chemotherapy in association with other site

involvement. The survival time for patients with oral lymphoma is 11 to 38 months [185].

Fig. 43. Non-Hodgkin lymphoma. (Courtesy of Dr. William Schiro, Lansing, MI.)


Multiple myeloma

Frequency/incidence

Multiple myeloma is a malignancy of plasma cells with variable systemic presentations. It is a

rare disorder that is usually seen after the age of 40 years, with a mean age of occurrence of 60years [188,189,190].

Signs and symptoms

Multiple myeloma may be asymptomatic [191] or associated with the signs and symptoms of

anemia, leukopenia, thrombocytopenia, hypercalcemia, and renal disease [188,192]. Oral in-

volvement may be associated with jaw and tooth pain, tooth mobility, paresthesia, soft tissue

swelling, and pathologic fracture [188,192].


The cause of this plasma cell cancer is unknown.


The panoramic radiograph is the choice for detecting multiple lesions of myeloma. Periapical

radiographs may also detect the changes in alveolar bone.

Image hallmarks

Multiple myeloma exhibits a varied radiographic appearance. The lesions are radiolucent and

may exhibit a well-defined or poorly defined border (Fig. 44). They may be unilocular or multi-

locular, and there may be multiple areas of bone destruction. The lesion may lack any reactive

or defined border, which gives the lesion a ‘‘punched out’’ appearance [192].

Management

Isolated lesions (plasmacytoma) are treated by radiation therapy [190,191]. Disseminated dis-

ease is treated by chemotherapy [190].

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Neuroimaging of neck pathology

Charles Lee, MDa,*, Tirbod Fattahi, DDS, MDb,Gregory Caldwell, DMD, MDc

aDepartment of Diagnostic Radiology, University of Kentucky Chandler Medical Center, 800 Rose Street,

Lexington, KY 40536-0293, USAbPrivate Practice, Maxillofacial and Facial Esthetic Surgery, 280 East Town Street, Suite C,

Columbus, OH 43215, USAcDivision of Oral and Maxillofacial Surgery, College of Dentistry, University of Kentucky, 800 Rose Street,

Room D-508, Lexington, KY 40536-0297, USA

Computed tomography (CT) scanning in the head and neck region has become an integral

part of the preoperative evaluation of tumor in defining the full extent of anatomic involvement,

and the relation of the tumor to vital vascular and neurologic structures. CT utilizes the same

ionizing X rays as plain-film radiography, except the X-ray beam is a thin, collimated linear

beam, single but more often multiple; in plain films, a single beam is used, which dispersesoutward. In CT, the beam attenuated by the object being studied then is detected by a crystal

detector and converted to electric energy. In plain film, the attenuated beam then strikes a

photoemulsion silver-based film, causing a photochemical reaction, which can then be processed

into a photograph. Thus, the CT scan is not a real image of a real object, whereas the plain-film

radiograph is. Basically, the object being studied casts a shadow (absorbs the X ray so that it does

not penetrate to the film) of a real object. In CT, the final picture is a reconstructed computer

simulation. Nevertheless, the simulation does accurately reflect the real anatomy.

Unlike plain film, CT scanning takes thousands of small images and actual X-ray beam ex-posures compared with the one shot in plain film. Because the beam is so thin, however, the

overall tissue absorption is about equal to, and sometimes less than, the amount of radiation

exposure encountered in plain-film radiography. To generate a picture utilizing a matrix, there

must be a way to spatially encode the thin X-ray beams of CT. This is accomplished in part by

the rotating ring, with single, multiple, and radial beams, by incrementing in 1� intervals the

X-ray tube and the crystal detectors around the object being studied, and taking pictures at each

incremental rotation. In MR imaging, the spatial encoding is accomplished by applying small,

linear, magnetic gradients, and thus frequency encoding, in the X direction, and phase encodingin the Y direction. The current CT technology then utilizes continual scanning but incrementing

in a helical or spiral fashion to reduce further the CT scanning times, as opposed to the earlier

scan utilizing one slice, stop, move table, and repeat. The latest technology places the crystal

detectors in arrays or banks, rather than the linear-or circular-oriented single row of detectors.

None of the new technologies increases anatomic resolution but instead reduces scanning times,

which benefits CT angiography or cinefluoroscopic CT.

The electric signal is then analyzed by Fourier transformation, which further adds informa-

tion about spatial encoding. The spatially encoded electric signal, by means of back projection,can then be used to determine how bright or dark each pixel of the picture matrix should be.

Resolution as high as a 1024 · 1024 matrix can then be created for temporal bone imaging.

More often, a 512 · 512 matrix is used for most CT scanning of the head and neck.

To generate a gray-scale image, a zero point needs to be established. CT intensity readings

are assigned Hounsfield units (HUs), with the zero value representing water and cerebrospinal


E-mail address: [email protected] (C. Lee).


PII: S 1 0 6 1 - 3 3 1 5 ( 0 2 ) 0 0 0 0 7 - 0


fluid (CSF) because the original CT scanners only studied the head. Higher HUs indicate a

denser material, which attenuates the CT beams, such as bone with a þ1000 HU, and blood (30–

100 HU) and muscle appear bright or white. Negative HUs include air with a �1000 HU and

fat (<�100 HU), which appear to be dark or black. There are no exact HUs for each type of tis-sue because very small volumes of the tissue being analyzed may not be accurately measured due

to the partial volume averaging of an adjacent tissue type. In addition, the HUs of water, using the

same CT machine, vary each week, which is why they are routinely calibrated with a phantom

disc of reference density.

The main advantage of CT in head and neck imaging is the ability to capture entire slices in

less than a second, which is advantageous in the uncooperative, moving patient. MR imaging

requires at least a 3- to 4-minute scanning time without motion. The rapid MR scanning tech-

niques do not provide the same high spatial resolution of the conventional MR pulse sequences.Rather, the fast MR techniques are better for MR angiography or cinescopic imaging, such as

joint motion or cardiac imaging.

The other advantage with CT compared with MR imaging is in determining whether there is

bone destruction. Bone destruction can be implied on MR imaging by abnormal signal where

bone should be. However, the CT often shows far more bony destruction than what was pre-

dicted by MR imaging. Yet the two may actually be complementary. Because patients tolerate

CT better than MR imaging, and CT does not have the many dangers and contraindications of

MR imaging, CT probably is the best first study; however, if the soft tissue information isnot answered by CT, MR imaging should also be obtained.

This article focuses on CT scanning of various head and neck pathologies with occasional MR

imaging, whenever it was the better method. The findings of both are discussed.

Sialadenitis [1]

Frequency/incidence

The incidence of sialadenitis depends on the population at risk and whether the causative

agent is viral, bacterial, or related to sialolithiasis (stones), autoimmune disorders, or iatrogenic.

For instance, postoperative acute bacterial infections occur in 0.004% to 0.74% of patients after

major oral surgical procedures, whereas the incidence would be much less in non-surgical

patients. Viral causes are uncommon, with mumps being the most common. Sialadenitis is a

common occurrence following oral cavity radiation therapy for carcinoma.

Signs and symptoms

The affected glands are swollen, tender, and painful, and may be enlarged. The face may be

swollen, and the patient may have fever. If the causative agent is sialolithiasis, sharp pain may

be present. In postradiation sialadenitis, the mouth is dry and painful and eating may not be

tolerated.


The most common viral organisms producing sialadenitis are rubella and various staphylo-

coccal and streptococcal bacterial agents. As the gland becomes swollen and enlarged, the ducts

may become obstructed and begin to dilate. Eventually, the infection may rupture out of the

gland to produce floor-of-the-mouth or upper neck abscesses. With chronic inflammation of

the submandibular gland, the palpable mass, or stone, may be referred to as a Kuttner tumor.

Of these stones, 80% to 90% occur in the Wharton duct because of its low gravity–dependent

location, in addition to factors such as an alkaline pH level, which favors stone formation.Nearly all stones (85%) occurring within the Wharton duct appear toward the distal end, and

not often within the gland itself. Only 10% to 20% of stones occur in the Stensen duct. The more

superficial location of the Stensen duct makes the parotid gland more prone to infection than

the submandibular gland.

56 C. Lee et al / Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) 55–72


CT demonstrates the calculi well in sialolithiasis. MR imaging, however, is much better

for demonstrating dilation of the intraductal portions of the affected salivary gland. Therefore,

the imaging method will depend on the clinical cause of the acute sialoadenitis. Sialography iscontraindicated in acute suppurative sialoadenitis because it may exacerbate the infectious proc-

ess and cannulation may further injure the already swollen duct opening.

Image hallmarks

The most common appearance on CT scan is a high-density stone seen in the floor of the

mouth (Fig. 1). The affected gland may be enlarged and there may be secondary signs of inflam-

mation, such as fat stranding. Intraductal dilatation is better seen on MR imaging as enlarged

linear branching structures. Both modalities also demonstrate extensive reactive lymph nodes ofwhich some may be enlarged by size into the adenopathic range (>1.0- or 1.5-cm diameter).

With chronic dilatation, a ranula may develop as well (see section on ranulas).

Fig. 1. Sialadenitis. Axial postcontrast CT shows enlarged bilateral submandibular glands with enlarged ducts (arrows)

seen as branching low-density structures.

57C. Lee et al / Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) 55–72

Management

Surgical excision is the treatment of choice in acute suppurative bacterial sialoadenitis if a

well-defined fluid pocket is seen representing abscess within the affected glands and if the glandruptures into the adjacent soft tissues. Removal of the obstructing stone is also necessary. If

there are no discrete abscess pockets, then appropriate antibiotic therapy should suffice.

Retropharyngeal abscess [2,3]

Frequency/incidence

The incidence of occurrence for an abscess to occur as a direct extension of a pharyngeal/

tonsillar inflammatory process is rare. The majority of retropharyngeal abscesses represent an

extension via the lymphatic system into the lateral retropharyngeal node of Rouviere, thus

explaining the characteristic location. If this process ruptures out of the lymph node, the patient

is at risk for mediastinitis as the infection accesses the danger space of Gradinsky and Holyoke,

which communicates from the skull base down to the mediastinum (this is a potential space

between the retropharyngeal and prevertebral space). Very rarely, the suppurative process may

spread through the superior constrictor muscle to involve the parapharyngeal fat-filled space.Because of the involvement of the muscle, these patients will present with torticollis, severe neck

pain, and a palpable laterally located neck mass.

Signs and symptoms

If the process directly suppurates through the muscle, the patient will present with torticollis,

trismus, and a laterally located neck mass. If the process is confined to the lymph node of Rou-

viere, then pain and dysphagia as well as fever will be the presenting symptoms.


The most common organisms producing pharyngitis/tonsillitis include b streptococci, staph-

ylococcus aureus, and H. influenza. The most common abscess is in the lateral retropharyngeal

space, caused by infection draining to the location node of Rouviere. The less common cause is

direct erosion through the superficial mucosa, muscles, and then to the retropharyngeal space.


Because of the acuteness of symptoms, pain, and possibly difficulty with breathing, and the

fact that the most common population involved is children, CT scan of the neck is the study of

choice. MR images would be degraded by motion and breathing-motion artifacts.

Image hallmarks

The most common appearance on CT scan is a low-density, usually well-defined, and some-

times irregularly margined area in the lateral neck region, medial to the carotid space and ante-

rior to the prevertebral muscles (Fig. 2). The walls of the abscess may be faintly enhanced with

usually well-defined margins when the abscess is contained within the lymph node. If the abscess

has ruptured out of the node, the margins will be indistinct. The presence of a well-defined low-

density fluid pocket is important for surgical planning. An ill-defined pocket without well-de-

fined walls represents an early abscess in the phlegmon stage, and is thus not a well-defined

pocket that can be surgically identified and drained.The more significant finding is if the bilateral fat-filled parapharyngeal spaces show irregular

contrast enhancement and replacement of low-density fat with soft tissue density with a low-

density fluid pocket, then the clinical prognosis is more severe, because infection is now within

the space that contains branches of the vagus nerve.


If the abscess pocket appears to be more lateral in location and at the angle of the jaw, there

may be an infected second branchial cleft cyst (BCC).

Management

Surgical excision is the treatment of choice if a well-defined fluid pocket is seen.

Thyroglossal duct cyst [2,4]

Frequency/incidence

The thyroglossal duct cyst (TDC) is the most common congenital anomaly of the neck and

accounts for about 70% of all congenital lesions of the neck. This cyst occurs in the young pop-

ulation (0–18 years old), with 70% of cysts encountered before the age of 30 years. In most cases(65%), TDC occurs in the infrahyoid location, followed by the suprahyoid region (20% of cases),

and at the level of the hyoid bone (15% of cases). In 20%, the TDC may occur in the base of the

Fig. 2. Retropharyngeal abscess. Axial noncontrast CT scan in a child shows a low-density pocket of fluid in the right

retropharyngeal space. This is the lateral retropharyngeal node of Rouviere, which drains the pharynx with the source of

infection being a superficial mucosal pharyngitis. The classic retropharyngeal abscess occurs in this node, which normally

can be seen in most children. Note the extensive reactive nodes in the posterior triangles on both sides.


tongue at the foramen cecum. The suprahyoid TDCs are located in the midline, whereas the

infrahyoid TDCs are off the midline. Although TDCs are benign lesions, less than 1% are

associated with carcinomas, most commonly a papillary carcinoma of the thyroid gland.

Signs and symptoms

A soft tissue mass is the most common presentation. If these TDCs become infected, how-

ever, then the usual findings of cellulitis/infection are present, including pain, redness, tender-

ness, but rarely fever.


The thyroglossal duct is a remnant of tissue track fromwhich the thyroid glandmigrates down-

ward from the base of the tongue (foramen cecum) to its anterior location in the lower neck. The

course of the TDC is from the foramen cecum down to and in front of the hyoid bone, underneath

the hyoid bone, and posterior to the hyoid bone, before taking aU-turn to head down the anterior

neck to the thyroid gland. This remnant of the duct fails to involute and secretes fluid, which

becomes the cyst. Often, these cysts are not detected until repeat infection of the anterior neck

occurs.


Either CT or MR imaging can evaluate TDC well. The main imaging feature is a ‘‘cystic’’

fluid-filled sharply marginated mass, usually anterior to the hyoid bone. On CT, the TDC is

of low or fluid density unless it is infected. There usually is no abnormal contrast enhancementunless the TDC is or has been infected in the past. On MR an image, the cyst has characteristic

fluid signal, dark on the T1W and bright on the T2W images. If there has been infection, the

fluid may be more proteinaceous and thus have a higher signal than water on the T1W images.

Image hallmarks

The key imaging feature for diagnosis is that the cyst is both in front of and behind the hyoid

bone, thus encasing it (Fig. 3). Furthermore, the anterior portion of the cyst appears embedded

into the overlying strap muscles, with the muscles in front of as well as behind the TDC. Care

should be taken to examine the floor of the mouth as well, because a diving ranula may mimic aTDC. The ranula does not encase the hyoid bone, however, nor does it appear embedded within

the overlying strap muscles.

Management

Surgery is the preferred treatment, particularly if there has been repeat bouts of infection.

The TDC, along with the affected portion of the hyoid bone, is resected (Sistrunk procedure),

and the tract is resected. If the hyoid bone and tract are not resected, the TDC will recur.

Dermoid of the floor of the mouth [4]

Frequency/incidence

Dermoidcysts are the rarestof all cystic lesionsof theheadandneck.About 7%of all cystic lesions

of the body occur in the head and neck region. About 80% of all dermoid cysts are found in the

orbital, oral cavity, and nasal region. Dermoid cysts comprise about 22% of all midline neck

lesions.


Signs and symptoms

If the lesion is within the oral cavity, there may be compression of the Wharton duct and thus

presentation with sialoadenitis of the submandibular gland. Otherwise, local mass effect is prob-

ably the main clinical finding.

Etiology/pathology

The popular explanation is that ‘‘rests’’ of epithelial cells become trapped in the floor of the

mouth as the first and second branchial clefts. These cysts may be epidermoid, dermoid, or ter-atoid cysts, depending on the germ cell layers found.


Either CT or MR imaging performs well in imaging this entity. The presence of fatty tissue,

which is low signal on CT and high signal on MR imaging (with the added finding of chemical

shift between fat and water), with other tissue density will help in the diagnosis. Measurements

of the density, or HUs, will yield numbers in the minus range up to �100 units. MR imaging,

however, can better discriminate fatty from other soft tissues. Epidermoid cysts may resemble

water or fluid, whereas dermoids will have fatty tissue rather than water signal. If calcificationor a tooth is seen, the diagnosis of a teratoid cyst can be made.

Fig. 3. Thyroglossal duct cyst (TDC). Axial postcontrast CT scan shows a large, multilocular cystic structure at the level

of the hyoid bone (black arrow), with the cyst both in front of and behind the hyoid bone, thus incorporating the hyoid.

This cystic structure is also imbedded in the overlying strap muscles, which is classic for a TDC. The contents of the cyst

are more dense than water, and the walls are slightly thick. These latter changes are related to past infection of the TDC.


Image hallmarks

The low-signal, sharply marginated lesion in the floor of the mouth has fatty signal character-

istics (Fig. 4). There is also soft tissue mixed with the fatty tissue, and the appearance of multiple

fat lobules resembling a collection of marbles is fairly characteristic of dermoid cysts. MR imag-

ing, with its direct coronal view, can delineate the relationship of the cyst to the mylohyoid

muscles for surgical approach. An external approach can be made if the cyst is below the

muscle. Above the muscle, an intraoral approach is needed.

Management

Surgical resection is the preferred treatment.

Fig. 4. Dermoid of the floor of the mouth. Axial postcontrast CT scan shows a large, well-circumscribed low-density (fatty

tissue by Hounsfield units) lesion, with a speckled appearance in the floor of the mouth located centrally (arrowhead). The

speckledorbubblyappearanceof thedermoid is characteristic.Therearealsomanyreactive level-Inodes, butnot adenopathy.


Cystic hygroma [4]

Frequency/incidence

Cystic hygromas occur most commonly in the head, neck, and axilla. They comprise about5.6% of all benign lesions in infancy and childhood. The most common location of cystic

hygromas is either the lateral neck in the posterior triangle or in the floor of the mouth. There

is no sex or race predilection. About 50% to 60% of lesions are present at birth, with nearly 80%

detected by the age of 2 years.

Signs and symptoms

If uncomplicated, cystic hygromas present as fluctuant, transilluminating, compressible, non-

tender mass lesions of the neck, which may enlarge with time.


This disease process is related to abnormalities of the lymphatic system, allowing large,

loculated fluid collections to occur in the lateral neck region. There are four distinct pathologic

types of which the cystic hygroma is the most common. Other types include cavernous lymph-

angioma, capillary or simple lymphangioma, and vascular/lymphatic malformation or the so-

called lymphangioma/hemangioma.With themalformations that contain venous structures, there

may be calcified phleobliths, which help to identify this malformation.

There are several etiologic theories in which either primitive lymphatic sacs fail to drain intothe jugular vein or there is abnormal sequestration or abnormal budding of the lymphatics.

Failure to drain lymphatic fluid results in fluid collections occurring most characteristically

(90% of cases) in the posterior triangle region (whereas BCCs most often are related to the an-

terior triangle).


Either CT or MR imaging demonstrate these lesions well. The main advantage of MR imag-

ing is the ability to obtain directly information from other imaging planes besides the usual axial

projection.

Image hallmarks

The most common appearance on CT scan are low-density, usually well defined fluid pockets

in the posterior triangle, and which are typically seen in fetal cystic hygroma (frequently inTurner syndrome) (Fig. 5). The cyst may be unilocular or, more likely, multilocular. The cyst

is low signal on T1W and high signal on T2W images. The location in the posterior triangle

is classic and may help to separate this lesion from a BCC. The multilocular appearance is

also typical. The floor-of-mouth cystic hygroma may be somewhat difficult to separate from a

ranula, but the latter does not occur in newborn infants.

Separation of the cystic hygroma from a venous/capillary lymphangioma can be made

with the presence of phleboliths, whereas the hemangiomatous type will display contrast

enhancement.

Management

Surgical excision is the treatment of choice if the fluid collection is large. If there has been

infection of the cystic hygroma, surgery should be performed.


Second branchial cleft cyst [5]

Frequency/incidence

Cysts, fistulas, and sinus tracts can occur related to the four branchial clefts. The following

lists the four types of BCCs in descending order of frequency of occurrence:

Second BCC: Most common form; 92% to 99% of all BC anomalies

First BCC: Second most common form; 68% cysts, 16% sinuses, 16% fistulas

Third BCCFourth BCC

very rare; no well documented incidences of occurrence.

Signs and symptoms

Although this is a fluid-filled cyst, it usually is not noticed until after an upper respiratory

infection with secondary infection of the BCC. With sinus tracts, there may be chronic drainage

from the neck.


There are five mesodermal arches separated by clefts. Remnants of the cleft or pouch are

trapped; thus a cyst is formed and named after the cleft from which it arose.


Either CT or MR imaging can diagnose this well. If the cyst occurs in a child, the fast scan-

ning times of the CT scan may work better. On the CT scan, body settings (level 30, window

�

Fig. 5. Cystic hygroma. Axial T2W images through the floor of the mouth show a multiseptated fluid collection in the

floor of the mouth on both sides. Fluid is very bright or white on this pulse sequence. The floor of the mouth is a typical

location, but the classic location is the posterior neck in the posterior triangle.


340) work well for the neck and for demonstrating these cysts. Uncomplicated BCCs will have

fluid signal characteristics on CT (low density) with sharp margins, unless there has been super-

imposed infection. The BCC is also low signal on T1W and high signal on T2W images. If the

cyst is infected, on the T1W images the signal may be higher than that of water. There is no

enhancement of the BCC unless there has been prior infection, in which case only the marginsare enhanced.

Image hallmarks

The most common of these cysts is the second BCC; this cyst is characteristically located

at the angle of the jaw, and is superficial to the carotid artery and jugular vein and posterior to

the submandibular gland, which may be displaced forward and—along the anterior margin of

the sternocleidomastoid muscle. Thus, BCCs tend to occur in the anterior triangle of the neck,

instead of the posterior triangle where cystic hygromas/lymphangiomas tend to occur. There

should be no abnormal contrast enhancement unless the BCC is secondarily infected. In

Fig. 6, the second BCC is in a characteristic location; however, there is a ‘‘dirty’’-appearingfat (so-called fat stranding), which indicates an inflammatory process—in this case, a cellulitis

as well as the infected second BCC—which is why the margins are not discrete. There is no ab-

normal contrast enhancement. There is marked enlargement of level-5 posterior triangle nodes

on both sides but the enlargement is greater on the right.

Fig. 6. Infected second branchial cleft cyst. Axial CT scan with contrast in a child shows cystic structure at the angle of

the mandible with irregular margins. The cyst is anterior to the sternocleidomastoid muscle and thus is in the anterior

triangle. The cyst is displacing the left submandibular gland in an anterior direction as well as compressing the right

jugular vein. There is also retropharyngeal edema, but not an abscess (arrow).


In addition, there is edema in the danger space of Gradinsky and Holyoke, which communi-

cates freely with the mediastinum. This potential space exists between the retropharyngeal space

in front and the posterior prevertebral space. If untreated, the infectious process can track down

to the lung and produce a mediastinitis.First BCCs are the next most common BCC, and may occur within the external auditory ca-

nal, at the angle of the jaw, and parotid gland. Third and fourth BCCs are more complicated

and beyond the scope of this article. The following sections list characteristics and locations

of BCCs and sinus tracts:

First BCC

Possible sites of BCCs are around pinna of ear and external auditory canal and around the

angle of the jaw.

Second BCCSecond BCC type I lies beneath the platysma and cervical fascia and anterior to the sterno-

cleidomastoid (SCM) muscle. It arises from the remnant of tract joining the cervical sinus of

HIS to skin. Type II is the most common and is adjacent to and adherent to the carotid/jugular.

Type III courses between the internal carotid artery (ICA) and external carotid artery (XCA) to

the lateral wall of the pharynx. Type IV is a columnar lined cyst, adjacent to wall of the pharynx.

Sinuses and fistulas

Sinuses and fistulas are more are common in children. Cysts are more common in adults.Classic sinuses and fistulas are superficial to the CCA and IJV in the anterior triangle, displacing

the SMG anterior at the angle of the mandible. CT shows a thin smooth ring with slightly higher

than cerebrospinal fluid signal (mucoid). If the cyst is infected, CT shows a thick enhanced rim.

There may be a sinus tract extending from the cyst up to lateral pharynx wall, between the ICA

and XCA, with the fistula extending up to the palatine tonsils.

Third branchial sinus tract

The third branchial sinus tract arises from the apex of the pyriform sinus and extendsbetween the CCA and vagus nerve to the lower lateral neck, ICA, and vagus nerve, and down

to the thyroid cartilage.

Fourth branchial sinus tract

The fourth branchial sinus tract arises from the apex of pyriform sinus and extends down to

and loops under the left aortic arch and right subclavian artery, back up to and between the

XCA and ICA to lateral neck.

Management

Surgical excision is the treatment of choice. If there is a third and fourth BCC, the anatomy is

muchmore complicated andmay require opening of the chest to get to these latter cysts or sinuses.

Ranula [4,6]

The term ranula comes from the Latin derivative for frog, because this entity causes fullness

of the floor of the mouth like a bullfrog.

Frequency/incidence

Ranula is very rare. There is a reported incidence of 3% in a series of 1303 salivary gland cysts.

Signs and symptoms

Signs include an expanding mass in the floor of the mouth, but may also involve the anterior

upper neck. There may be a history of repeat bouts of sialadenitis, but most often there is a his-

tory of recent surgery in the oral cavity with injury of the Wharton duct.



Ranulas are also known as mucoceles or retention cysts of the Wharton duct. Either a stone

or surgical injury occludes the Wharton duct. The submandibular gland continues to produce

secretions, which then cause the duct to dilate (simple ranula). With increased pressure, the ductmay rupture, spilling the mucinous contents into the soft tissues. Thus, the simple ranula

becomes a diving or a plunging ranula if it passes through the floor of the mouth/mylohyoid

muscles and presents as a soft tissue mass in the upper and anterior neck region. If the ranula

crosses the midline, it becomes a dissecting ranula.

Fig. 7. Diving ranula. Axial T2W MR of the floor of the mouth shows a large fluid collection (large bright, white

structure) centered on the sublingual space that contains the Wharton duct. The small white arrow marks the normal

midline fat-filled lingual septum, which is bowed to the left side by the ranula. The ranula has also herniated across the

midline to the left side. The ranula has herniated through the mylohyoid muscles to become a diving ranula, which is

now lateral to the mandible.



This entity can be studied well by either CT orMR imaging. The ability to obtain direct sagittal

and coronal images using MR imaging makes it more useful in assessing complicated ranulas.

Image hallmarks

Because a ranula is a fluid-like cavity, it will behave as fluid does on CT and MR imaging. On

CT, the ranula is low density, which may not be exactly the density of water if infected. On MR

imaging, the ranula is low signal on T1W and high signal on T2W images (Fig. 7). The key to

the diagnosis is that the dilated fluid sac is in the sublingual space where the Wharton duct lies.

On the coronal views, if the ranula is above the floor of the mouth or mylohyoid muscle, thenit is considered simple, unless it crosses the midline to the other side (dissecting ranula). If the

ranula is below the floor of the mouth or mylohyoid muscle, then it becomes a diving ranula; if

it makes it down the anterior neck, it becomes a plunging ranula. Usually, the soft tissue mass/

fluid cavity occurs in the submental region or angle of the jaw region.

Management

Surgical excision is the preferred treatment.

Floor-of-the-mouth abscess [4]

Frequency/incidence

The frequency of occurrence of this abscess depends on its location, the health of the patient,

and whether a surgical procedure is being performed. Development of infection following dentalextraction is not common, but is the most common cause for infection in the floor-of-the-mouth

region.

Signs and symptoms

Symptoms include facial swelling with redness and tenderness, and if severe, the patient may

be febrile with other systemic findings of infection.


Fig. 8 shows a case where the abscess was a result of dental extraction. Usually following

dental extraction, the infectious process arises within the masticator space and thus involves

the pterygoid muscles or the overlying masseter muscles. The infection can spread down from

the gingival ridge into the floor of the mouth and below if the infection squeezes through the

mylohyoid muscles.


Because the patient is in discomfort and can not hold still for a prolonged time, CT is the

preferred imaging method. Furthermore, CT may identify an unsuspected calculus within the

salivary gland ducts, which may be the cause of the infection; bony involvement or osteomyelitis

may be also be detected by CT.

Image hallmarks

The most characteristic appearance on either CT or MR imaging is a contrast enhancement in

a ringlike fashion with a central area of fluid signal. This represents the abscess capsule that is

enhancing and may be regular or irregular shaped. Usually, there is extensive reactive


adenopathy as well as fat stranding and skin thickening—all secondary signs of an inflammatory

process. Squamous cell carcinoma of the neck usually does not show significant contrast

enhancement.

Management

Surgical excision is the preferred treatment if there is a well-defined fluid pocket.

Chondrosarcoma [7]

Frequency/incidence

The incidence of chondrosarcoma of the cartilage in the neck is very low. The overall inci-

dence of all sarcomas is 0.3% to 1.0% of all laryngeal malignant tumors.

Fig. 8. Floor-of-mouth abscess. Axial CT of the neck with contrast shows a large low-density collection of fluid with

abnormal ringlike contrast enhancement (arrow). Just posterior to this is the compressed submandibular gland, which is

now enhancing because it is also infected. The contrast-enhanced proximal portion of the Wharton duct can be seen

(arrowhead). There are multiple, bilateral, reactive nodes. The normal right submandibular gland is also seen.


Signs and symptoms

Symptoms probably occur late and are related to mass effect, producing difficulty breathing

or difficulty in swallowing.


The cause of chondrosarcoma is probably spontaneous genetic mutation and is usually not a

transmitted disease process.


CT demonstrates the calcific and characteristic chondroid pattern of calcification. MR-imag-

ing findings are nonspecific, particularly because the bony nature and calcific pattern is not seen

on MR images.

Image hallmarks

The most characteristic appearance on CT scan is an expansile lesion of the thyroid or cricoid

cartilage with chondroid pattern of calcification without frank bony destruction or soft tissue

mass (Fig. 9). Thus, a squamous cell carcinoma that destroys cartilage but does not expand it

Fig. 9. Chondrosarcoma. Axial CT with contrast shows an expansile tumor of the cricoid cartilage with internal

amorphous type of calcification typical of cartilaginous tumors. There is no soft tissue mass, but the expanded cricoid

cartilage is narrowing the airway.


can be differentiated. A hemangioma of the cartilage may have a similar appearance, but

because of its vascular nature, it will enhance, whereas a chondrosarcoma will not. Another pos-

sibility would be a Kaposi sarcoma in an HIV-positive patient, but which would have a more

destructive nature and may be difficult to differentiate from squamous cell carcinoma, which

comprises nearly 95% of all head and neck malignant tumors.

Management

Surgical excision may be the treatment of choice if the chondrosarcoma is lower grade and

totally confined to the cartilage. If the cricoid is involved, a total laryngectomy may be needed.

Venous lymphangioma [5,8]

Frequency/incidence

Please refer to the discussion on cystic hygromas.

Signs and symptoms

Venous lymphangiomas present as large, cutaneous lesions, which may have a dark bluish or

purplish appearance and also appear to be enlarged or varicoid veins.

Fig. 10. Venous lymphangioma/hemangioma. Axial CT of the neck with contrast shows a serpiginous collection of

enhancing vessels in the left posterior triangle region but with extension through the muscle to the superficial skin. The

more common cystic hygroma (lymphangioma) would not enhance but also is located commonly in the posterior triangle

(behind the sternocleidomastoid muscle).



Please refer to the discussion on cystic hygromas.


Either CT or MR imaging demonstrate this lesion well.

Image hallmarks

The most characteristic appearance on either CT or MR images is a contrast-enhancing mass,

which, despite its size, does not have significant mass effect, and is located superficially (Fig. 10).

Management

The size of the lesion and cosmetic deformity determine whether surgical intervention isrequired.

References

[1] Som P, Brandwein M. Salivary glands. In: Som P, Curtin H, editors. Head and neck imaging. St. Louis: Mosby;

1996. p. 846–66.

[2] Hudgins P, Jacobs I, Castillo M. Pediatric airway disease. In: Som P, Curtin H, editors. Head and neck imaging.

St. Louis: Mosby; 1996. p. 573–4. 585–6.

[3] Som P, Curtin H. Fasciae and spaces. In: Som P, Curtin H, editors. Head and neck imaging. St. Louis: Mosby;

1996. p. 744.

[4] Smoker W. Oral cavity. In: Som P, Curtin H, editors. Head and neck imaging. St. Louis: Mosby; 1996. p. 501–2,

506–10.

[5] Weissman J. Nonnodal masses of the neck. In: Som P, Curtin H, editors. Head and neck imaging. St. Louis: Mosby;

1996. p. 794–8, 802–6.

[6] DeGraff RV. Ranulas and plunging ranulas. Emedecine.com 2:7.

[7] Curtin H. Larynx. In: Som P, Curtin H, editors. Head and neck imaging. St. Louis: Mosby; 1996. p. 658–62.

[8] Benson M, Zadvinskis D, Som P, et al. Embryology and congenital cystic lesions. In: Som P, Curtin H, editors. Head

and neck imaging. St. Louis: Mosby; 1996. p. 763–9.


Angiographic evaluation of the head and neck

Larry L. Cunningham, Jr, DDS, MD*,Joseph Van Sickels, DDS, M. Todd Brandt, DDS

Division of Oral and Maxillofacial Surgery, College of Dentistry, University of Kentucky,

800 Rose Street, Room D-508, Lexington, KY 40536-0297, USA

Facial trauma, craniomaxillofacial surgery, and certain idiopathic events can cause a variety

of vascular pathologies. Those of special interest to craniomaxillofacial surgeons include the

following: superficial vascular malformations (hemangiomas), intraosseous vascular tumors

(central hemangioma of bone), aneurysms (false or true), arteriovenous fistulas (including

carotid-cavernous fistulae (CCFs)), fibrovascular tumors (including juvenile nasopharyngeal an-

giofibromas), and carotid body tumors. These vascular injuries can lead to airway compromise,significant hemorrhage, irreversible neurologic damage, or death. Appropriate management be-

gins with early diagnosis. Because vascular injuries can go unrecognized in the acute setting

when a diagnosis is based solely on clinical history and physical examination, interventional ra-

diology has become the standard for definitive diagnosis.

Angiography, the diagnostic mainstay of interventional radiology, provides images of normal

and abnormal anatomical structures. It is also used to diagnose a vascular injury whose presence

is suggested by noninvasive radiographic and clinical examinations. Thus, it is a useful adjunct

before any surgical identification and repair, ligation, or ablation of indicated vasculature.When combined with endovascular embolization, angiography can successfully manage vascu-

lar injury, spontaneous vascular pathology, and congenital vascular anomalies. Complications

of angiography combined with embolization are varied but infrequent. Ischemic tissue necrosis

after artery occlusion can involve large areas of the maxillofacial region. More serious unpre-

dictable sequelae range from permanent neurologic morbidity to death.

A working knowledge of angiography will facilitate communication between craniomaxillo-

facial surgeons and interventional radiologists or interventional neuroradiologists. The images

and associated descriptions in this article are presented as examples of vascular abnormalitiesthat can be diagnosed with angiography.

Hemangioma

Frequency/incidence

Hemangiomas of soft tissue are benign vascular tumors. They are the most common tumor of

infancy and childhood, constituting 7% of all benign soft tissue tumors [1–3]. Hemangiomas are

found in 1.1% to 2.6% of neonates, and they eventually develop in 10% to 12% of children, more

often in girls than in boys (5:1). Approximately one fourth to one third of these tumors occur in

the head and neck region [1].


E-mail address: [email protected] (L.L. Cunningham, Jr.).


PII: S 1 0 6 1 - 3 3 1 5 ( 0 2 ) 0 0 0 0 8 - 2


Signs and symptoms

Hemangiomas may begin as a flat area of red pigmentation that rapidly progresses to become

a red to purple raised mass. A thrill or bruit may be detectable in arteriovenous hemangiomasbecause of the abnormal connection between arterial and venous circulation [1,2]. Approxi-

mately 20% of hemangiomas grow large enough to require intervention [2]. Indications for

medical or surgical treatment are compression of vital structures, hemorrhage as the result of

trauma, and cosmetic concerns [2].


Hemangiomas are the result of a benign proliferation of vascular channels lined with endo-

thelium [1,2].


Computed tomography (CT), ultrasonography, magnetic resonance imaging (MRI), and

Doppler studies are useful noninvasive diagnostic techniques [2,3]. Angiography is performed

before embolization or to map the extent of a lesion if surgery is planned [2,3].

Image hallmark

Angiography will show a hypervascular tumor with an intense capillary blush and earlyvenous filling [2] (Fig. 1).

Fig. 1. Angiogram of a peripheral hemangioma involving the skin and subcutaneous layer of the forehead of a 6-month-

old infant. (From Burrows P. Diagnostic imaging in the evaluation of vascular birthmarks. Dermatol Clin 1998;16:462;

with permission.)

74 L.L. Cunningham Jr. et al / Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) 73–86

Management

Reported therapies include compression therapy for localized lesions, intralesional or sys-

temic corticosteroids, argon laser therapy, cryotherapy, sclerosing agents, and embolization

with or without surgical identification and removal [2].

Central hemangioma of bone

Frequency/incidence

Central hemangiomas of bone are rare intrabony lesions; some are caused by trauma, others

are hamartomas, and still others are true neoplasms [1]. Hemangiomas of bone are more com-

mon in female patients and occur most frequently in patients in the first and second decades oflife [1,3]. Common sites include the skull, the vertebrae, and the jaws; lesions appear twice as

often in the mandible as in the maxilla [1].

Signs and symptoms

Clinical findings associated with central hemangiomas include the following: spontaneous

bleeding from the gingival sulcus, mobility of teeth, gingival discoloration, facial swelling

or asymmetry, and a detectable thrill or bruit [3]. Indications for medical or surgical

therapy are compression of vital structures, hemorrhage as the result of trauma, and cosmeticconcerns [2].


Hemangiomas are the result of a benign proliferation of vascular channels lined with epithe-

lium [1,2].


CT, ultrasonography, MRI, and Doppler studies are useful noninvasive diagnostic tech-

niques [2,3]. Angiography combined with embolization can effectively reduce intraoperative

hemorrhage [3].

Image hallmark

Angiography will show a hypervascular tumor with an intense capillary blush and early

venous filling [2] (Fig. 2).

Management

Reported therapies include systemic corticosteroids, laser therapy, sclerosing agents, radia-

tion therapy, and embolization with or without surgical identification and removal [2].

Aneurysm

Frequency/incidence

Intracranial and extracranial aneurysms rarely affect the head and neck [4]. They have beenreported to occur after facial trauma, head trauma, orthognathic surgery, and other head and

neck surgery. Seventy percent of aneurysms result from blunt trauma, whereas 25% result from

penetrating trauma [5].

75L.L. Cunningham Jr. et al / Atlas Oral Maxillofacial Surg Clin N Am 11 (2003) 73–86

Fig. 2. (Top) CT showing a hemangioma of the right maxilla. (Bottom) Angiographic image of the same maxillary lesion.


Signs and symptoms

Aneurysms typically remain asymptomatic until they rupture, usually within 1 month of their

development; rupture causes a thromboembolic event or hemorrhage [6]. Aneurysms are often

unrecognized in the acute clinical setting because the onset of symptoms can be delayed for afew hours to a few weeks after the traumatic incident [7]. Symptoms can range from neck stiff-

ness and pain to focal or severe neurologic defects resulting from showering emboli [8,9]. Dis-

section or expansion of traumatic lesions in the neck can cause airway compromise, soft tissue

deformity, asymmetry, or cranial nerve deficits, and can even mimic a tonsilar abscess [10]. Mas-

sive posterior epistaxis may occur as the result of a post-traumatic pseudoaneurysm of the intra-

cavernous portion of the internal carotid artery (ICA) and can be life threatening [11,12].


Aneurysms are classified as either true or false (pseudoaneurysm). True aneurysms result

from the partial tearing or rupture of only the muscularis and intimal layers of an artery; this

rupture allows the adventitia to prevent blood extravasation [6]. Complete transection of one

side of an arterial wall leads to the formation of a pseudoaneurysm or pulsating hematoma that

is contained by contiguous tissues. The organizing clot forms a psuedofibrous capsule with a

liquefied central matrix. Without an arterial coat, the pressure in the hematoma increases until

the pressure in the periarterial zone equals the mean arterial pressure [4]. The endothelial lining

frequently produces a pseudointima continuous with the arterial lumen [4]. Hematoma liquefac-tion leads to the formation of a pulsating mass that can either rupture or continue to enlarge [4].

The instability of the vessel wall in both true and false aneurysms poses the constant threat of

hemorrhage or infarction as the result of a thromboembolic event [6]. Left untreated, these

lesions can lead to stenosis, dissection, arteriovenous fistulas, or hemorrhage [9,13].

Fig. 3. (A) Anterior-posterior (A-P) image of an aneurysm of the right internal carotid artery-posterior wall at the

junction with the posterior communicating artery (not shown). (B) Lateral view. This patient presented with transient

ischemic attacks and weakness of the left arm and face. An A-P (C) and lateral (D) view of an aneurysm of the basilar

artery with the dome pointing down and to the right.


Fig. 3 (continued )



Angiography is the preferred imaging method for diagnosis, surgical mapping, or definitive

treatment through endovascular approaches.

Image hallmark

An aneurysm appears as a projection or out-pouching from the parent vessel and may extendwith dissection through soft tissue [6] (Fig. 3).

Management

Medical treatment with anticoagulant therapy may allow time for spontaneous healing of apseudoaneurysm. However, medical therapy alone rarely accomplishes complete resolution, and

there is a continuous threat of thrombotic emboli or spontaneous and rapid dissection leading

to airway compromise [1]. The traditional surgical approach includes excision of the aneurysmal

pouch and either direct closure or placement of a patch graft (synthetic or autologous). More

recently, the placement of stents and coils through a vascular approach has proved successful.

In addition, detachable balloons placed proximal and distal to the pseudoaneurysm have been

shown to be effective [11,13,14]. Early treatment is imperative if detrimental sequelae are to be

prevented [14].

Carotid body tumors

Frequency/incidence

Carotid body tumors are very rare, and their exact incidence is unknown.

Signs and symptoms

The presenting problem is usually a pulsatile and expansile mass at the angle of the mandible.

Cranial nerve dysfunction can involve the vagus, hypoglossal, and cervical sympathetic nerves.

More commonly, patients have vague complaints such as headache, neck and ear pain, hoarse-

ness, syncope, tinnitus, and dysphagia [15].

Fig. 3 (continued )



Tumors arising at the bifurcation of the internal and external carotid arteries are called carotid

body tumors. Because of their rarity and interesting histologic appearance, they are also known

by several other names: glomus tumors, paragangliomas, nonchromaffin paragangliomas, andchemodectomas. These tumors are derived from neural crest tissue; their malignant potential

is low but definite [15,16].


Duplex scanning with color flow images can help to determine the dimensions of the tumor

and can display the vascular flow. CT scans are useful for evaluating neck masses in general, and

MRI techniques can readily differentiate the carotid body tumor from other soft tissues in the

Fig. 4. Angiogram of a carotid body tumor showing the high vascularity of the tumor: (A) lateral and (B) A-P views.

This tumor receives vascular supply from three branches of the external carotid artery.


neck. Angiography is the definitive diagnostic test for these lesions and is helpful in surgical

planning.

Image hallmark

Carotid body tumors are extremely vascular and may appear as an angiomatous tumor [15].

Findings include early tumor blush and splaying of the internal and external carotid arteries at

the carotid bifurcation [16] (Fig. 4).

Management

When the differential diagnosis includes carotid body tumor, needle aspiration or biopsy

is contraindicated because of the vascularity of the tumor. In the presence of severe hyper-

tension, screening for elevated serum catecholamine concentration may be warranted, as may

other laboratory studies to rule out the presence of other functioning paraganglionic tumors

(eg, pheochromocytomas). Surgical removal of these masses is indicated. Selective preopera-

tive embolization of the tumor’s blood supply is helpful in decreasing intraoperative blood

loss.

Carotid-cavernous fistula

Frequency/incidence

Carotid-cavernous fistulas (CCFs) are vascular connections between the carotid artery and

the cavernous sinus and are associated most frequently with trauma to the base of the skull [15].

Signs and symptoms

Pulsating exophthalmus, edema of the preseptal orbital tissues, enlargement and restriction

of motion of the extraocular muscles, and eventual ocular ischemia are caused by the reverse

flow through the venous system. Patients with these symptoms should undergo frequent oph-

thalmologic examinations with checks of visual acuity and ocular pressure. Changes in visual

acuity necessitate immediate treatment [17].


CCFs are classified as indirect or direct. Indirect CCFs occur by spontaneous dural arterio-

venous communications supplied by the ICA or the external carotid artery. Multiple lesions can

exist within the cavernous sinus wall. The exact causes of indirect CCFs are unknown. Direct

(traumatic) CCFs most often demonstrate a single communication between the ICA and the

cavernous sinus. Causes other than blunt or penetrating trauma include direct surgical trauma,

ruptured aneurysm, collagen deficiency syndromes, fibromuscular dysplasia, or arterial dissec-

tion [17,18].


Selective cerebral angiography is the diagnostic standard. CT scanning and MRI can be help-

ful in determining whether brain damage exists or in identifying fractures.

Image hallmark

In the case of a traumatic transection of the ICA, the cavernous sinus will opacify, and theremay be decreased filling of intracranial vasculature from ipsilateral angiography (Fig. 5). Vas-

cular injuries and associated pseudoaneurysm may be seen. Venous outflow from the cavernous

sinus will be seen through the ophthalmic venous system. This flow may continue to the facial


vein and the external jugular vein. Some patients may exhibit outflow through posterior drain-

age of the cavernous sinus and the superior and inferior petrosal sinuses. Superior drainage may

be displayed as opacification of the sphenoparietal sinus, which places the patients at risk of

intracerebral hemorrhage. Most often, a combined pattern will be seen [17].

Management

Patients with severe proptosis, increasing intraoccular pressure, and severely declining vis-

ual acuity may require lateral canthotomy as a temporary step for preventing loss of vision.

Endovascular approaches with either balloon embolization or coil embolization are the pre-

ferred means of treatment. Proximal suture ligation of the ICA has been shown to be ineffec-

tive and may induce or increase steal syndrome. Thus, this intervention should be avoided[19].

Dissecting carotid aneurysm

Frequency/incidence

Aneurysms of the intracranial and extracranial portions of the carotid artery are rare andmay be difficult to diagnose. Aneurysms of the extracranial carotid artery compose fewer than

5% of all extracranial arterial aneurysms [20].

Signs and symptoms

The signs and symptoms can vary greatly depending on the location of these aneurysms. Cer-

vical aneurysms can bulge into the lateral parapharyngeal wall, mimicking a neck mass [21,22].

The mass may or may not pulsate, depending on whether a thrombus has formed within thelumen [20]. Symptoms may include hemorrhage, either otorrhagia or epistaxis. Nerves immedi-

ately adjacent to the expanding mass may be compressed, and Horner syndrome has been de-

scribed in several cases of carotid aneurysm. Patients with extracranial aneurysm may exhibit

paralysis of cranial nerves IX, X, XI, and XII. Patients with intracranial aneurysm may exhibit

headaches, nausea, vomiting, drowsiness, transient ischemic attacks, and loss of vision and

Fig. 5. Angiogram of a cavernous-carotid fistula following a gunshot wound to the head. The fistula is demonstrated by

the blush in the cavernous sinus and during angiography of the right internal carotid artery.


hearing. Associated signs and symptoms such as fever and upper airway obstruction can be

related to the underlying cause of the aneurysm (see Etiology/pathophysiology).


Dissecting carotid aneurysms may be congenital or caused by trauma or infection [23,24].They have been reported to occur after blunt trauma to the head and after a tonsillectomy.

Although trauma appears to be the most common cause of these aneurysms, they may develop

for several reasons, which vary according to the age of the patient. These aneurysms have

occurred in patients younger than 5 years and in patients older than 40 years. Dissecting carotid

aneurysms may be caused by a deep space infection of bacterial or mycotic origin. When they

occur as a complication of neck space infection, the diagnosis may be difficult. Patients with

fibromuscular dysplasia, Marfan syndrome, or Ehlers-Danlos syndrome, and those who have

undergone radiation therapy, appear to be at greater risk of carotid aneurysm. The lesionmay be a true or false aneurysm. True aneurysms are usually congenital, whereas false aneu-

rysms are usually the result of trauma or infection.


CT scanning, MRI, and magnetic resonance angiography have been used to image carotid

aneurysms; however, arteriography is the method of choice.

Image hallmark

Arteriography reveals a large outpouching of contrast beyond the walls of the ICA (Fig. 6).

Management

The choice of treatment depends on the location of the lesion and on the patient’s condition.

Surgical intervention is used most often for lesions in the neck; this treatment involves resection

Fig. 6. Dissecting carotid aneurism following blunt head trauma. Note the saclike projection extending superiorly from

the internal carotid artery.


of the lesion with repair of the carotid artery. Balloons and coils are used most often to treat

intracranial lesions. The use of balloons allows an assessment of the status of the contralateral

cerebral blood flow.

Arteriovenous malformations

Frequency/incidence

Arteriovenous malformations (AVMs) are rare lesions that may be congenital or may result

from trauma. Congenital lesions grow as the patient ages and may increase in size dramatically

during puberty or pregnancy [25].

Signs and symptoms

The clinical presentation of AVMs depends on the characteristics of the lesion. Patients with

lesions in the head and neck may exhibit increased intracranial pressure, mass effect, or stealsyndrome. Symptoms may include disfigurement, pain, bruit, or hemorrhage. When they occur

in the region of the maxilla and mandible, AVMs may cause facial swelling, loose teeth, tinnitus,

and headaches.


The clinical behavior and prognosis associated with AVMs are determined by the presence

and degree of shunting. Congenital lesions are presumed to have been present at birth and

to have grown with age. Traumatic lesions usually result from penetrating injuries and can

originate from the internal or external carotid arteries, the vertebral arteries, or a transectedvessel.

Fig. 7. Angiogram of an arteriovenous malformation that presented as a swelling in the patient’s oropharynx. (A)

Lateral view of the right carotid angiogram. Note there is also a cavernous-carotid fistula with drainage in an anterior

direction to an enlarged superior ophthalmic vein. (B) On the A-P view of the selected left vertebral angiogram, there is

contribution to the arteriovenous malformation.



A Doppler ultrasound probe may be used to examine the lesion and to determine the need for

further tests. Angiography may be either diagnostic or therapeutic. When the lesions are verylarge and involve both bone and soft tissue, MRI may be used to determine the extent of soft

tissue involvement [26].

Image hallmark

The appearance of AVMs varies greatly depending on their location, size, and degree of

shunting and collateral circulation (Fig. 7).

Fig. 7 (continued )


Management

Patients with a bruit or palpable shunting are candidates for treatment. AVMs resulting

from trauma lend themselves more easily to surgical intervention. Endovascular embolizationwith various materials has been used alone or in combination with surgical intervention. Endo-

vascular embolization can be combined with percutaneous embolization (micropuncture

directly into the lesion with the placement of microcoils). Recent case reports [27–29] indicate

that the use of histoacrylic glue for both endovascular and percutaneous embolization is a

promising treatment.

References

[1] Waldron CA. Bone pathology. In: Neville BW, Bouquot J, Allen C, Damm D, editors. Oral and maxillofacial

pathology. Philadelphia: WB Saunders; 1995. p. 443–92.

[2] Herbreteau D, Aymard A, Jhaveri HS, et al. Current management of cervicofacial superficial vascular mal-

formations and hemangiomas. In: Connors JJ, Wojak JC, editors. Interventional neuroradiology: strategies and

practical techniques. Philadelphia: WB Saunders; 1999. p. 317–26.

[3] Larsen PE. Diagnosis and management of vascular malformations. In: Williams TP, Stewart JC, editors. Surgical

pathology. Vol. 5. Philadelphia: WB Saunders; 2000. p. 432–45.

[4] Lanigan DT, Hey JH, West RA. Major vascular complications of orthognathic surgery: false aneurysms and

arteriovenous fistulas following orthognathic surgery. J Oral Maxillofac Surg 1991;49:571–7.

[5] Bula WI, Loes DJ. Trauma to the cerebrovascular system. Neuroimaging Clin N Am 1994;4:753–72.

[6] Acosta C, Williams PE Jr, Clark K. Traumatic aneurysms of the cerebral vessels. J Neurosurg 1972;36:531.

[7] Pretre R, Reverdin A, Kalonji T, et al. Blunt carotid artery injury: difficult therapeutic approaches for an

underrecognized entity. Surgery 1994;115:375–81.

[8] Laitt RD, Lewis TT, Bradshaw JJ. Blunt carotid arterial trauma. Clin Radiol 1996;51:117–22.

[9] Simionato F, Righi C, Scotti G. Post-traumatic dissecting aneurysm of extracranial internal carotid artery:

endovascular treatment with stenting. Neuroradiology 1999;41:543–7.

[10] Liebman KM, Rosenwasser RH, Heinel LA. Endovascular management of aneurysm and carotid-cavernous fistulae

from gunshot wounds to the skull base and oropharynx. J Craniomaxillofac trauma 1996;2:10–16.

[11] Chae SW, Choi G, Lee HM, et al. Intrasaccular detachable platinum coil embolization for traumatic

pseudoaneurysm treatment of a cavernous carotid artery. Otolaryngol Head Neck Surg 2001;124:230–1.

[12] Ghorayeb BY, Kopaniky DR, Yeakley JW. Massive posterior epistaxis. A manifestation of internal carotid injury

at the skull base. Arch Otolaryngol Head Neck Surg 1988;114:1033–7.

[13] Crow WN, Scott BA, Guinto FC Jr, et al. Massive epistaxis due to pseudoaneurysm treated with detachable

balloons. Arch Otolaryngol Head Neck Surg 1992;118:321–4.

[14] Jean WC, Barrett MD, Rockswold G, et al. Gunshot wound to the head resulting in a vertebral artery

pseudoaneurysm at the base of the skull. J Trauma 2001;50:126–8.

[15] Moore WS, editor. Surgery for cerebrovascular disease. 2nd edition. Philadelphia: WB Saunders; 1996. p. 432–9.

[16] Zierler RE. Diagnosis and management of cerebrovascular disease. New York: McGraw-Hill. 1995. p. 491–500.

[17] Connors JJ, Wojak JC, editors. Interventional neuroradiology: strategies and practical techniques. Philadelphia:

WB Saunders; 1999. p. 215–25.

[18] Lasjuanias PL, Berenstein A, editors. Surgical neuroangiography New York: Springer; 1992. p. 317.

[19] Fox AJ, Vinuela F, Pelz DM, et al. Use of detachable balloons for proximal artery occlusion in the treatment of

unclippable cerebral aneurysms. J Neurosurg 1987;66:40–6.

[20] Unal OF, Hepgul KT, Turantan MI, et al. Extracranial carotid artery aneurysm in a child misdiagnosed as a

parapharyngeal abscess: a case report. J Otolaryngol 1992;21:108–11.

[21] Haynes DS, Schwaaber MK, Netterville JL. Internal carotid artery aneurysms presenting as neck masses.

Otolaryngol Head Neck Surg 1992;107:787–91.

[22] Yoshizaki T, Teranishi S, Matsui O, et al. Internal carotid artery aneurysm presenting as a large pharyngeal mass.

Ann Otol Rhinol Laryngol 2000;109:690–2.

[23] Coley SC, Clifton A, Britton J. Giant aneurysm of the petrous internal carotid artery. Diagnosis and treatment.

J Laryngol Otol 1998;112:196–8.

[24] Halliday AW, Mansfield AO. Congenital arteriovenous malformations. Br J Surg 1993;80:2–3.

[25] Zachariades N, Mezitis M, Rallis G, et al. Vascular malformations in a 3-1/2 year old child. Oral Surg Oral Med

Oral Pathol Oral Radiol Endod 2001;91:271–3.

[26] Warren DJ, Hoggard N, Walton L, et al. Cerebral arteriovenous malformations: comparison of novel magnetic

resonance angiographic techniques and conventional catheter angiography. Neurosurgery 2001;48:973–82.

[27] Corsten L, Bashir Q, Thornton J, et al. Treatment of a giant mandibular arteriovenous malformation with

percutaneous embolization using histoacrylic glue: a case report. J Oral Maxillofac Surg 2001;59:828–32.

[28] Kaneko R, Tohnai I, Ueda M, et al. Curative treatment of central hemangioma in the mandible by direct puncture

and embolization with n-butyl-cyanoacrylate (NBCA). Oral Oncol 2001;37:605–8.

[29] Siu WW, Weill A, Gariepy JL, et al. Arteriovenous malformation of the mandible: embolization and direct injection

therapy. J Vasc Interv Radiol 2001;12:1095–8.


Magnetic resonance imaging of the head and neck

Larry L. Cunningham, Jr, DDS, MDa,*,David M. Nadler, DMD, MDa, Charles Lee, MDb

aDivision of Oral and Maxillofacial Surgery, College of Dentistry, University of Kentucky, 800 Rose Street,

Room D-508, Lexington, KY 40536-0297, USAbDepartment of Radiology, University of Kentucky, 800 Rose Street, Room HX-315D,


Computed tomography (CT) and magnetic resonance imaging (MRI) are used to detect

pathology of the head and neck. Although CT still has a superior role in detecting calcifications,bony pathology, fractures, and acute hemorrhage [1], MRI is now the preferred imaging method

for head and neck pathology. MRI allows superior tissue discrimination and fat- and water-sup-

pression imaging. Fat-suppression imaging has greatly improved the ability to detect abnormal

contrast enhancement in the head and neck region. Without this technique, abnormal contrast

enhancement appearing as a bright area may be hidden by the very bright signal of fat. Very

rapid MRI techniques now allow angiographic images and kinescopic (real-time) depiction of

movement. Injectable contrast agents (gadopentetate) aid in the differentiation of certain tumor

types and vascular lesions. Albumin-tagged agents which allow direct blood-volume calcula-tions have been developed and are now pending FDA approval. Injectable MR agents, specif-

ically for head and neck imaging, are also currently under development.

MRI, which uses nonionizing radiation from the radio-frequency (RF) band of the electro-

magnetic spectrum, functions by taking advantage of the weak magnetic properties of human

tissue. The patient is placed inside a large magnet with a uniform magnetic field. When the

hydrogen nuclei in the patient’s body are exposed to this magnetic field, they align with the field.

A sequence of RF pulses is then applied to the area of the body being evaluated; this signal must

be at the resonant frequency so that the body’s proteins can absorb it. These pulses create atransient magnetic field that is perpendicular to the main field; when exposed to this field, the

hydrogen nuclei in the body absorb energy and change the direction of their axis of rotation.

When the RF pulse is terminated, the nuclei again realign themselves with the external magnetic

field. Energy is released from the tissue as weak RF signals, which are received by coils in the

MRI device. The signals are rendered detectable by the application of an RF pulse that tips

the energized proton down by 90� to be detected as a current by the receiving coil [2–4]. Subject-

ing these signals to a series of computer operations translates the signal into an image.

The signals emitted from the excited proton have two components, which are referred to asT1 and T2 relaxation times. T1 is defined as the spin-lattice relaxation time, reflecting the lon-

gitudinal axis, and decays at a faster rate than the T2 relaxation time. This is the energy ex-

pended by the excited proton to the lattice that contains the proton. As the excited proton is

deflected by the 90� RF pulse toward the receiving coil and partially recovers to its free steady

state during the early phase of read-out, the signal is dominated by the T1 relaxation time. T2 is

defined as the spin-spin relaxation time and reflects the vertical axis. This is the energy expended

between the various protons that have been energized.


E-mail address: [email protected] (L.L. Cunningham, Jr.).


PII: S 1 0 6 1 - 3 3 1 5 ( 0 2 ) 0 0 0 1 1 - 2


Following the 90� pulse, the T2 signal decays faster than the predicted rate because of can-

cellation of signal vector by protons out of phase with each other. This results in the T2* (star)

signal, which forms the basis for gradient echo imaging. By applying another 180� pulse (refo-

cusing pulse), the protons reverse their direction and eventually come back into phase, generat-ing a signal or echo that can be repeated with other 180� pulses with eventual total decay of

signal. This echo or signal forms the basis of the standard spin-echo technique widely used

for most conventional MRI. When the proton has nearly recovered, the T2 relaxation signal

dominates. Thus, both T1-weighted and T2-weighted effects exist in all types of MR images,

but one effect usually dominates [2–4].

A T1-weighted image is produced by a short repetition time (TR) between pulse sequences

plus a short echo time (TE). Tissue with a short T1 decay produces an intense bright or white

MR image. Tissue with a long T1 decay produces a low-intensity signal and appears dark on a T1-weighted image [5]. OnT1-weighted images, fat is bright orwhite, cerebrospinal fluid (CSF) is dark

or black, and gray matter is slightly hypointense to white matter. This level of contrast makes

it possible for theMR image to render a high degree of anatomic detail. Thus, T1-weighted images

are useful for depicting small anatomic regions such as the temporomandibular joint (TMJ).

A T2-weighted image is acquired by using a long TR and a long TE. Tissue with a long T2

decay produces a high-intensity signal and appears as a bright area on the image. Tissue with a

short T2 decay produces a low-intensity signal and appears as a dark area on the image. On T2-

weighted images, fat becomes less bright compared with its appearance on T1 images. CSF isbright or white, and gray matter is slightly hyperintense (brighter) to white matter, which

appears dark or gray. In general, the T2 time of abnormal tissue is longer than that of normal

tissue. Thus, T2-weighted images are ideal for showing inflammatory changes and tumors.

This article discusses several diseases of the head and neck for which MR imaging has signifi-

cant advantages. Sample MR images accompany each description.

Osteomyelitis

Frequency/incidence

Osteomyelitis is an infection of bone that begins in the medullary cavity and extends to in-volve the cortical bone and periosteum. It is rare in the jaw in the absence of predisposing risk

factors such as an immunocompromised state, trauma, and radiation treatment for cancer [6,7].

Signs and symptoms

Pain and fever are the primary symptoms of both acute and chronic osteomyelitis. Swelling,

paresthesia, loose teeth, and sinus tracks can also be present. The white blood cell count, eryth-

rocyte sedimentation rate, and C-reactive protein concentration may be elevated, and blood cul-

tures may also be positive [6–8].


Osteomyelitis can spread hematogenously, as is most common outside the mandible, or by

direct spread from an adjoining structure. Odontogenic infections and trauma are the most

common causes of osteomyelitis in the jaw [6,7,9]. Acute osteomyelitis most often results from

infection with staphylococci or streptococci, although recent studies have shown positive

cultures for anaerobic bacteria in these infections. Chronic osteomyelitis results from untreated

or undertreated acute osteomyelitis [6,7].


Bone scintigraphy (radionuclide scanning), plain films, and CT scans have been used to diag-

nose and manage osteomyelitis. Although scintigraphy is still the preferred imaging method for


Fig. 1. Osteomyelitis. (A) T1 noncontrast image showing decreased signal in the marrow of the left mandibular angle,

thickening of the masticatory muscles, and loss of fat planes caused by edema. (B) T1 image with contrast showing

moderate increase in signal of the bone marrow of the left mandible and masticatory muscles. (C) T1 noncontrast image

showing loss of bone marrow signal. (D) T1 image with contrast showing heterogenous enhancement of the bone marrow

with enlargement of themandible. (FromReinert, S,WidlitzekH, VenderinkDJ. The value ofmagnetic resonance imaging

in the diagnosis of mandibular osteomyelitis. Br J Oral Maxillofac Surg 1999;37:459–463; with permission.)


Fig. 1 (continued )


localizing osteomyelitis, MRI has the advantage of providing good contrast between normal

and abnormal bone marrow, which aids in the early detection of osteomyelitis while offering

a significant increase in the level of anatomic detail [10,11].

Image hallmarks

On T1-weighted MR images produced with and without contrast enhancement, the normal

hyperintense signal of bone marrow fat is altered by inflammatory edema, and the signal inten-

sity of fatty tissue within the marrow is decreased (dark) when compared with a normal bonemarrow signal (Fig. 1). In addition, MR images may also show nonossified periosteal reaction

indicating bony response to the infection; this reaction appears as a thickened area of hypoin-

tensity surrounding the marrow [10].

Management

Appropriate antibiotic therapy, as indicated by culture and sensitivity, and surgical debride-

ment with or without hyperbaric oxygen therapy are the treatments of choice.

Head and neck abscess

Frequency/incidence

Head and neck abscesses are relatively common and are often odontogenic in origin. Other

sources include the sinuses, salivary glands, tonsils, traumatic wounds, and skin infections.

Signs and symptoms

The first symptoms of head and neck infections are pain and swelling. All infections involving

the fascial planes of the head and neck can become life threatening, and symptoms may include

trismus, stridor or airway compromise, inability to handle secretions, fever, and leukocytosis

[6,12].


Most head and neck infections are of dental, tonsillar, or salivary gland origin. These infec-

tions are most often caused by mixed flora indigenous to the oropharyngeal region.


Both CT images and MR images are of diagnostic benefit in the evaluation of infections of

the head and neck. If the patient’s airway is compromised, as may be the case with odontogenic

or pharyngeal infections, CT is generally used because of the discomfort and potential com-

plications that patients might encounter during the time required to generate an MR image.

MRI, however, is the preferred imaging method for delineating abscesses of the midface and

brain.

Image hallmarks

The affected tissues may demonstrate hypointensity on T1-weighted MR images and hyper-

intensity on T2-weighted images, but the images are not specific for any organism (Fig. 2).


Likewise, abscess formation will be displayed as a hypointense area on T1-weighted images

and hyperintense on T2-weighted images with an enhancing capsule or wall around the

abscess or invasion of adjacent tissue [13]. Alternatively, fungal infections appear dark on

the T2-weighted images because of their relative lack of water. Therefore, a fungal ballcan be separated from normal sinusitis changes, which are very bright on the T2-weighted

images.

Fig. 2. Peritonsillar abscess. (A) Axial T1-weighted image through the tonsillar area demonstrates a low-intensity mass

in the left tonsillar area with mass effect. (B) Axial T2-weighted image at the same level demonstrates increased signal

intensity of the abscess. (C) Coronal T2-weighted image shows a high-intensity abscess with a medial bulge of the

pharyngeal wall. (From Weber AL, Siciliano A. Radiologic evaluation of the neck: CT and MR imaging evaluation of

neck infections with clinical correlations. Radiol Clin North Am 2000;38:941–68; with permission.) Midface abscess is

seen in (D) an axial T1-weighted image of an orbital/sinus abscess from an aspergillosis infection and (E) a coronal view

of the same patient. The fungus has low signal and appears to be gray in contrast to the normal mucosa and normal

inflammatory changes, which are bright.


Management

Abscess drainage and appropriate antibiotic management are required for treatment of head

and neck infections. If the infection is life threatening, empiric antibiotic therapy should begiven in conjunction with surgical drainage. As culture and sensitivity studies become available,

the antibiotic spectrum should be narrowed.

Olfactory neuroblastoma (esthesioneuroblastoma)

Frequency/incidence

Unlike usual neuroblastomas, which occur predominantly in young children, olfactory neu-

roblastomas (ESTs) are rare lesions occurring in adults over a wide age range.

Signs and symptoms

The most common symptoms associated with ESTs are nasal obstruction, rhinorrhea, epis-

taxis, and pain [14]. This tumor may first appear as a polyp in the nasal roof or as a naso-

pharyngeal mass, but it is most commonly seen as an invasive lesion of the paranasal sinuses(especially the ethmoid) or of the anterior cranial fossa [14,15].


An EST is a neuroectodermal neoplasm that is believed to arise from the olfactory epithe-

lium, usually high in the nasal cavity close to the cribiform plate [14].

Fig. 2 (continued )



The most important aspect of MRI is its ability to accurately determine the extent of tumor

and to distinguish it from normal mucosa and from other pathologic changes such as inflamma-tion and retained secretions. T2-weighted spin-echo sequences and gadolinium-enhanced T1-

weighted MR images are best for demonstrating such distinctions [16] and are the images of

choice for all paranasal sinus tumors.

Image hallmarks

Fig. 3 shows a paranasal sinus tumor with a presentation typical of tumors in this region [14].

The tumor appears as a hypointense mass on gadolinium-enhanced T1-weighted images. The

degree of enhancement appears to correlate with the degree of vascularity of the tumor. The

tumor is further discriminated from associated sinusitis by T2-weighted spin-echo sequences,

on which the EST appears less intense than the highly intense changes associated with secondary

sinusitis. Because ESTs tend to grow along the various tiny perforating olfactory nerves, the

tumor commonly pierces the cribriform plate and becomes a subfrontal, extradural tumor. This

Fig. 3. Olfactory neuroblastoma. (A) T1-weighted image showing tumor filling the superior nasal cavity and ethmoid

sinus with extension into the anterior cranial fossa. (Courtesy of Pamela Van Tassel, MD, Philadelphia, PA) (B) T1-

weighted image showing an anteroposterior view of a similar tumor.


involvement through the cribriform plate is characteristic of ESTs but not of other paranasalsinus tumors, such as squamous cell carcinoma [10].

Management

Surgical excision with adjunctive radiation therapy is the preferred treatment for all para-

nasal sinus tumors. Because the cribriform plate is often involved by olfactory neuroblastoma,

this structure must be removed along with the tumor to prevent recurrence.

Pleomorphic adenoma

Frequency/incidence

Benign pleomorphic adenoma (BPMA) is the most common neoplasm of major and minorsalivary glands. BPMA accounts for 53% to 77% of parotid tumors, 44% to 68% of submandib-

ular tumors, and 38% to 43% of minor gland tumors [17]. Eighty-five percent of pleomorphic

adenomas occur in the parotid gland, which is by far the most common site of occurrence.

Roughly 60% of intraoral lesions are located on the palate [17,18].

Signs and symptoms

Regardless of the site of origin, pleomorphic adenomas are typically painless, slow-growing,firm masses.

Fig. 3 (continued )


Fig. 4. Pleomorphic adenoma. Gadolinium-enhanced T1-weighted (A) axial and (B) coronal MR images showing

bilateral synchronous pleomorphic adenomas of the parotid glands. (Ahn M. Familial mixed tumors of the parotid

gland. Head Neck 1999;21:773; with permission.)


Pleomorphic adenomas are derived from a mixture of ductal and myoepithelial elements [17].


CT images and MR images are the studies of choice for diagnosing pleomorphic

adenomas.

Image hallmarks

On CT images, BPMA appears hyperdense in comparison with the parotid; the tumor is

smoothly marginated with very little contrast enhancement (Fig. 4). If the tumor is small,

BPMA appears homogeneous. Larger tumors may contain low-density areas related to centralnecrosis, hemorrhage, or cystic degeneration. Calcifications are indicative of BPMA. On T1-

weighted MR images, the signal intensity is low to intermediate. On T2-weighted images, the

signal intensity is intermediate to high. When BPMA is associated with significant hemorrhage,

the image may be hyperintense on T1- and T2-weighted images.

Management

Surgical resection is the treatment of choice. Superficial tumors are best treated with super-

ficial parotidectomy; deep parotid tumors should be treated with total parotidectomy. Every ef-

fort should be made to spare the facial nerve, because the tumor does not invade the nerve.

When BMPA is treated by conservative enucleation, it commonly recurs. If BMPA is left un-

treated for an extended length of time, malignant transformation occurs in approximately

25% of cases [18].

Sinus mucocele

Frequency/incidence

Sinus mucoceles are relatively common lesions that occur most frequently in the frontal and

anterior ethmoid sinuses of persons between the ages of 13 and 80 years. Mucoceles occur less

frequently in the maxillary, posterior ethmoid, and sphenoid sinuses [18,19].

Signs and symptoms

The presentation of sinus mucoceles varies depending on their location. Because they occur in

the sinuses, they may grow to large dimensions before they become symptomatic, and may be

seen as incidental findings on images taken for other reasons. When they become symptomatic,

headache, rhinnorhea, and epistaxis may be seen. The classic frontal sinus mucocele may present

with proptosis of the globe.


Sinus mucoceles are accumulations of mucin that are completely encased by epithelium (ie,

they are true cysts). They generally occur after trauma, sinus surgery, or obstruction of the sinus

ostium.


CT and MRI are the preferred diagnostic procedures. Because mucoceles expand bone,

CT imaging is necessary to determine whether the bone is completely eroded. Also, CT imaging

of the nasal cavity may detect an anatomic lesion that is causing sinus obstruction. MRI


distinguishes inflammatory tissue from neoplastic tissue. MRI can also detect breakthrough

into the cranial vault.

Image hallmarks

Recently formed mucoceles contain a high degree of water and protein and produce a

hypointense signal on T1-weighted images and a hyperintense signal on T2-weighted images

(Fig. 5). Inspissated mucoceles with very low water content, as in cases of superimposed fungal

Fig. 5. Sinus mucocele. (A) Axial T1-weighted image through the ethmoid sinus demonstrates expansion on the right

with low intensity in the sinus consistent with mucocele. (B) Coronal view.


infections, have been reported to produce hypointense signals on T1- and T2-weighted

images [19].

Management

Surgical treatment either by debridement and curettage or marsupialization is recommended

[19].

Adenoid cystic carcinoma

Frequency/incidence

Adenoid cystic carcinoma (ACC) is a relatively common salivary gland tumor that occurs

most frequently in the minor salivary glands (50%), the submandibular glands (25%), and the

parotid gland (25%). The palate is the most common intraoral site. ACC occurs primarily in

middle-aged adults and is relatively rare in persons younger than 20. The tumor occurs fairlyevenly in men and women, although some studies have reported that it is slightly more likely

to occur in women [17,18].

Signs and symptoms

ACC usually occurs as a painful, slow-growing mass. The pain is often described as a dull

ache that gradually increases in intensity, which usually occurs before the appearance of any

noticeable swelling. Parotid tumors may cause facial nerve paralysis, and palatal tumors maycause ulceration.


ACC is a slow-growing tumor of salivary gland origin, composed of a mixture of ductal and

myoepithelial cells. These cells can be arranged in a cribriform, tubular, or solid pattern, with

the cribriform pattern being the most common [17]. Perineural invasion is common for ACC.

This invasion is usually detected at the time of recurrence rather than at the time of initialdiagnosis, and extension of the tumor is often beyond what can be detected radiographically.

Though the tumors grow slowly, local recurrence is common, and prognosis is poor.


Either CT or MRI demonstrate the primary salivary gland tumor. These imaging methods

play a complementary role in the evaluation of perineural tumor spread: MRI demonstrates

tumor spread along nerves, and CT demonstrates bony erosion and expansion.

Image hallmarks

When the tumor involves the parotid gland, it may appear benign with sharp margins. When

it involves the minor salivary glands, the tumor may appear to infiltrate the margins. CT and

MR images show abnormal soft tissue in the gland (Fig. 6). ACC shows enhancement with

contrast, whereas benign pleomorphic adenoma does not. The presence of adenopathy also

indicates malignancy. The imaging characteristics of this tumor are not specific; the tumor’s

appearance may resemble that of the more common mucoepidermoid carcinoma of the parotidgland. On MR images, abnormal contrast enhancement of the mandible indicates perineural

tumor spread along the V3 branch within the mandible. CT images may show bony erosion

of the canal and even widening of the foramen through which the nerve enters.


Fig. 6. Adenoid cystic carcinoma. (A) T2 axial view. (B) A different patient’s postresection of tumor showing recurrence

along inferior alveolar nerve.


Management

The preferred treatment for ACC is surgical excision with or without adjunctive radiation

therapy. ACC is a relentless tumor that is prone to local recurrence and eventual distant meta-

stasis. Because metastasis to regional lymph nodes is uncommon, neck dissection is not recom-mended. Because the overall prognosis for patients with ACC is so poor, regardless of

treatment, surgical morbidity should be carefully considered, especially when the tumor is large

or evidence of distant metastasis already exists [17].

Internal derangement of the temporomandibular joint

Frequency/incidence

Temporomandibular joint (TMJ) disorders are relatively common; 35% to 72% of the general

population display symptoms of this disorder. Epidemiologic studies have not shown a differ-ence in the sex and age distribution of TMJ disorders; however, most patients who seek treat-

ment are young women between the ages of 20 and 35 years [20].

Signs and symptoms

Symptoms of TMJ internal derangement include pain in the joint, joint sounds (popping,

clicking, crepitus), and changes in mobility of the mandible (decreased incisal opening, open

lock, closed lock).


Anterior disc displacement results from elongation of the capsular and discal ligaments and

concomitant thinning of the articular disc. These changes may be associated with trauma to the

joint, either macro- or microtrauma. Sources of macrotrauma are obvious (motor vehicle acci-dent, assault) and are often reported in the patient’s history. Sources of microtrauma are subtler

and usually associated with parafunctional habits [21].


Closed- and open-mouth MR images are the images of choice for evaluating the TMJ.

Image hallmarks

T1-weighted images of the TMJ disk display a hypodense biconcave structure, which should

be interposed between the hyperintense condylar head and articular eminence in the closed- and

open-mouth positions. Displaced disks will often be seen anterior to the condyle in the closed

position. If there is reduction of the disk on opening, then the open-mouth position will show

the disk in a more anatomic position. If there is no reduction of the disk, then it will continue to

be displaced anterior to the condyle when the mouth is open. A cinematic view of the TMJ and

disk can be seen using rapid gradient echo techniques incrementally imaging as the patient opens

and closes the mouth (Fig. 7).

Management

Management of internal derangement of the TMJ is aimed at reducing pain and increasing

range of motion to allow for normal function. Goals for function include interincisal opening


Fig. 7. Temporomandibular joint (TMJ). A closed (A) and open (B) T1-image of a normal condylar-disk relationship. A

closed (C) and open (D) image of the left TMJ of a patient with severe long-standing rheumatoid arthritis and with a

degenerated disk, which is anteriorly displaced. A closed (E) and open (F) T2 image of a nonrheumatoid patient’s

anteriorly displaced disk without reduction.


Fig. 7 (continued )


Fig. 7 (continued )


of 40 mm with lateral excursions of 5 to 7 mm. Physical therapy, a nonchew diet, occlusal

splints, nonsteroidal anti-inflammatories, and muscle relaxers have all been used in the nonsur-

gical therapy and management of symptomatic internal derangement. When these treatments

fail to improve symptoms, surgical treatments usually follow and might include arthrocentesis,

arthroscopy, or open arthrotomy.

Obstructive sleep apnea

Frequency/incidence

Obstructive sleep apnea is one in a spectrum of entities known collectively as sleep-disorderedbreathing. Although patients must have a polysomnogram (sleep study) to be diagnosed with

obstructive sleep apnea, it is one of the most common diagnoses given by sleep centers, and

reportedly affects 2% of women and 4% of men older than 30 [22].

Signs and symptoms

Snoring, apnea, and hypopnea during sleep are signs associated with obstructive sleep apnea

and can be evaluated by polysomnogram. In addition, physical characteristics may include

obesity, retrognathia, and a long, soft palate. Patients may complain of snoring and daytime

sleepiness. They may report falling to sleep very quickly (in bed, watching TV, or during other

activities) and may report never feeling rested after a full night’s sleep.


Obstructive sleep apnea is a complex disease process caused by collapse or obstruction of the

airway at one or multiple various levels, including the nasal airway, nasopharynx, oropharynx,

and hypopharynx.


Sagittal and axial MR images can depict an obstructed airway and help diagnose the level of

obstruction. Although such images are not necessary for diagnosis, they can be helpful in decid-

ing how to treat the patient with obstructive sleep apnea. Most practitioners use plain radiog-

raphy, especially lateral cephalometric radiographs, in their evaluation and treatment planning.

Image hallmarks

The soft palate and the tongue of patients with sleep apnea are much larger than those of

patients who do not have this condition (Fig. 8). The size of the nasopharyngeal airway is re-

duced. The upper airway is narrowed because the tongue is almost in contact with the back wall

of the oropharynx. Large tonsils may also narrow this upper airway.

Management

Management of obstructive sleep apnea is generally multidisciplinary. Treatments in-

clude continuous positive airway pressure machines; weight loss; dental appliances; and various

surgical options, including nasal reconstruction, uvulopalatopharyngoplasty, uvulopalatalflap, mandibular osteotomy with or without hyoid myotomy and suspension, base of ton-

gue surgery, tonsillectomy, maxillomandibular osteotomy and advancement, and tracheostomy

[23].


References

[1] Som PM, Curtin HD, editors. Head and neck imaging. Vol 1, 3rd edition. St. Louis, MO: Mosby; 1996.

[2] Council on Scientific Affairs . Magnetic resonance imaging [prologue]. JAMA 1987;258:3283–5.

[3] Future improvements in magnetic resonance imaging. Health Technol 1988;2:12–9.

[4] Council on Scientific Affairs. Fundamentals of magnetic resonance imaging. JAMA 1987;258:3417–23.

[5] Goaz PW, White SC, Pharoah MJ, editors. Goaz and White’s oral radiology: principles and interpretation. 4th

edition. St. Louis, MO: Mosby; 1999.

[6] Neville BW, Damm DD, Allen CM, et al. Pulpal and periapical disease. In: Oral and maxillofacial pathology. 2nd

edition. Philadelphia: WB Saunders; 2002. p. 107–36.

[7] Regezi JA, Sciubba J. Inflammatory jaw lesions. In: Oral pathology: clinical pathologic correlations. 3rd edition.

Philadelphia: WB Saunders; 1999. p. 381–96.

[8] Carek PJ, Dickerson LM, Sack JLDiagnosis and management of osteomyelitis. Am Fam Physician 2001;63:

2413–20.

[9] Delbalso AM, Hall RE. Diagnostic imaging of maxillofacial and fascial space infections. In: Topazian RG,

Goldberg MH, editors. Oral and maxillofacial infections. 3rd edition. Philadelphia: WB Saunders; 1994. p. 148–50.

[10] Reinert S, Widlitzek H, Venderink DJ. The value of magnetic resonance imaging in the diagnosis of mandibular

osteomyelitis. Br J Oral Maxillofac Surg 1999;37:459–63.

Fig. 8. An MRI comparing the airway of a normal patient (A) versus a patient with obstructive sleep apnea (B). Note

the difference in size of the airways. (C) and (D) show a similar comparison in the axial view. (From Schwab RJ. Upper

airway assessment. Otolaryngol Clin North Am 1998;31 948–9; with permission.)


[11] Tehranzadeh J, Wong E, Wang F, et al. Imaging of osteomyelitis in the mature skeleton. Radiol Clin North Am

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[12] Goldberg MH, Topazian RG. Odontogenic infections and deep fascial space infections of dental origin. In:

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1994. p. 198–250.

[13] Weber AL, Siciliano A. CT and MR imaging evaluation of neck infections with clinical correlations. Radiol Clin

North Am 2000;38:941–68.

[14] Neville BW, Damm DD, Allen CM, et al. Soft tissue tumors. In: Oral and maxillofacial pathology. Philadelphia:

WB Saunders; 2002. p. 437–96.

[15] Regezi JA, Sciubba J. Connective tissue lesions. In: Oral pathology: clinical pathologic correlations. 3rd edition.


[16] Lund VJ, Howard DJ, Lloyd GA, et al. Magnetic resonance imaging of paranasal sinus tumors for craniofacial

resection. Head Neck 1989;11:279–83.

[17] Neville BW, Damm DD, Allen CM, et al. Salivary gland pathology. In: Oral and maxillofacial pathology.


[18] Regezi JA, Sciubba J. Salivary gland pathology. In: Oral pathology: clinical pathologic correlations. 3rd edition.


[19] Nicolai P, Redaelli de Zinis LO, Tomenzoli D, et al. Sphenoid mucocele with intracranial invasion secondary to

nasopharyngeal acinic cell carcinoma. Head Neck 1991;13:540–4.

[20] Eberhard D, Bantleon HP, Steger W. Functional magnetic resonance imaging of temporomandibular joint

disorders. Eur J Orthod 2000;22:489–97.

[21] Okeson JP. Management of temporomandibular disorders and occlusion. 4th edition. St. Louis, MO: Mosby; 1998.

[22] Coleman J. Complications of snoring, upper airway resistance syndrome, and obstructive sleep apnea syndrome in

adults. Otolaryngol Clin North Am 1999;32:223–34.

[23] Troell RJ, Riley RW, Powell NB, et al. Surgical management of the hypopharyngeal airway in sleep disordered

breathing. Otolaryngol Clin North Am 1998;31:979–1012.


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