PEDIATRIC DENTISTRY/Copyright © 1982 byAmerican Academy of Pedodontics

Special Issue/Radiology Conference

Radiology in the diagnosis of oral pathologyin children

Henry M. Cherrick, DDS, MSD

Introduction

As additional information becomes available aboutthe adverse effects of radiation, it is most importantthat we review current practices in the use of radio-graphs for diagnosis. It should be remembered thatthe radiograph is only a diagnostic aid and rarely cana definitive diagnosis can be made with this tool. Rou-tine dental radiographs are often taken as a screeningprocedure m frequently this tool is used to replacegood physical examination techniques. A review ofprocedures often employed in the practice of dentistryreveals that a history is elicited from the patient (usu-ally by an auxiliary) and then radiographs are takenbefore a physical examination is completed. Thissequence should be challenged inasmuch as mostpathologic conditions that occur in the facial bonespresent with clinical symptoms. The following ques-tions should be addressed before a diagnostic radio-graph is taken.

1. When was the last screening radiograph taken?2. Is there a clinical finding that suggests under-

lying osseous pathology?3. Does the medical or dental history suggest

underlying osseous pathology?4. Will a radiograph augment the physical findings?5. What type of radiograph will be most helpful?Diagnostic radiographs should only be taken when

one of the following conditions exist:1. A physical or history finding would suggest an

underlying pathological condition,2. When the physical finding is inadequate to make

a differential diagnosis or to allow treatment.Employment of the above procedures would signifi-

cantly reduce the number of diagnostic X rays taken.It is recognized that screening radiographs {exclud-

ing bite-wing radiographs) in children are generallynonproductive without positive, physical findings.With this fact in mind a child should probably haveone screening radiograph (panorex) during the initialvisit and not have another until the permanent denti-tion has erupted. Bitewing radiographs should betaken whenever the physical examination suggests

that the possibility of caries or pulpal pathologyexists.

Pathological conditions excluding caries and pulpalpathology, that do occur in the oral cavity in childrencan be classified under the following headings:1. Congenital or developmental anomolies; 2. Cysts ofthe jaws; 3. Tumors of odontogenic origin; 4. Neo-plasms occurring in bone; 5. Fibro-osseous lesions; 6.Trauma.

A good understanding of the clinical signs andsymptoms, normal biological behavior, radiographic in-terpretive data, and treatment of pathological condi-tions which occur in the oral cavity will allow us to bemore selective in the use of radiographs for diagnosis.

It is not the purvue of this presentation to cover allof the disease entities that occur in the jaws. The morecommon or significant conditions which effect the wel-fare of the child will be presented.

Congenital or Developmental AnomoliesThe early recognition of congenital or developmen-

tal anomolies often determines whether the eventualtreatment is successful or not. It is imperative thatthe clinician know the physical symptoms and radio-graphic features of these conditions.

"Dens in Dente"It is most important to identify the condition

known as "dens in dente" as soon as possible. Recogni-tion of this condition before the tooth erupts into theoral cavity may save the patient the loss of this ante-riot tooth.

As the term indicates, "dens in dente" implies atooth within a tooth and is caused by an invaginationof all layers of the enamel organ into the dental papil-lae. As the hard tissues ave formed, the invaginatedenamel organ produces a small ,tooth within the futurepulp chamber. It occurs in above 5% of the populationand can best be diagnosed by radiographic examina-tion. The maxillary lateral incisors are most fre-quently involved and the pulp is usually exposed due

PEDIATRIC DENTISTRY: Volume 3, Special Issue 2 423

to defects in the enamel and dentin. If this conditionis recognized before the eruption of the tooth, surgicalexposure and an appropriate restoration will oftenavoid loss of the tooth or endodontic therapy. Not in-frequently, after the tooth has erupted, a periapicallesion is associated with this condition.

Dilaceration and Supernumerary RootsDilaceration is a term used to describe angulation

or a sharp bend or curve in the root or crown of aforming tooth. The condition is thought to occur dueto trauma during the period in which the tooth isforming. Consequently, the position of the calcifiedportion of the tooth is changed and the remainder ofthe tooth is formed at an angle. Most teeth have somedegree of dilaceration. It is most important to identifythis condition prior to the extraction of any tooth. Asa general rule of thumb it is wise to take a preopera-tive radiograph on any tooth to be extracted.

ConcrescenceConcrescence occurs when two independently form-

ing teeth become fused by either cementum or bone.Microscopically, these teeth are found to have sepa-rate pulp canals and roots. Both of the teeth may beerupted or unerupted or one tooth may be imbeddedand the other erupted. It has been estimated that .5%of all teeth have some form of concrescence. It is gen-erally thought that this condition occurs when twoteeth are forced together after they have completelyformed. Clinically these teeth give a dull sound whenthey are tapped. If this condition is not identifiedbefore an extraction it is possible the adjacent, non-offended tooth will also be extracted.

AnodontiaTrue anodontia implies the absence of teeth. It may

be total involving, both the deciduous and permanentdentitions, as in some patients with ectodermal dys-plasia, or it may be partial (hypodontia) and limitedto a single tooth or group of teeth. It is estimated that7% of the population exhibit at least one congenitallymissing tooth. In a study by Dolder the mandibularsecond premolar was the most commonly missingtooth followed by the maxillary premolar and thenthe maxillary lateral incisor. Whenever there is a miss-ing tooth or delayed eruption of a tooth it is wise totake a diagnostic radiograph. The early identificationof numerous missing or impacted teeth may facilitatethe early diagnosis of ectodermal dysplasia, or clei-docranial dysostosis.

Ectodermal dysplasia is a hereditary disease thatinvolves all structures derived from the ectoderm.Males are affected much more freqently than females.Clinical findings are the absence or reduction in theamount of hair (Hypotrichosis) an absence of sweat

sebaceous glands, temperature elevation, dry skin, de-pressed bridge of the nose, protrusion of the lips andcomplete or partial endodontia.

A common cause for partial endodontia is the expo-sure of the developing tooth germ to X radiation.

Supernumerary TeethTeeth in excess of the normal compliment are re-

ferred to as accessory or supernumerm’y. Supernumer-ary teeth frequently inhibit the normal compliment ofteeth to erupt. An accessory tooth between the maxil-lary central incisor is called a mesiodens. Supernumer-ary teeth which develop distal to the third molar arecalled a distomolar and one which is located buccal orlingual to the molar is called a p~ramolar. Super-numerary teeth occur nine times more frequently inthe maxilla than in the mandible. It is estimated that5% of the caucasian population of this country exhibitone or more supernumerary teeth.

Numerous supernumerary and impacted teeth areseen in a condition called cleidocrs, nial dysostosis.This symptom frequently leads to the diagnosis of thedisease. Cleidocranial dysostosis is characterized bydelayed closure of the fontanelles, delayed closure ofcranial sutures and presence of wormian bones, under-development of the upper face -- :particularly themaxilla, underdevelopment of the pssanasal sinuses,and prognathism. There is frequently an absence orhypoplasia of the clavicals so that the patient canapproximate the shoulders with ease.

Cycts of the Jaws

The cysts of the jaws fall into two major categories.The odontogenic cysts which develop from epitheliumof odontogenic origin are more frequently seen in thechild than the developmental cysts which come fromentrapped epithelium in fissures and sutures. Thecysts of the jaws present with a clinical sign of swell-ing or with secondarily infected pain. When thesecysts enlarge to any degree there is usually expansionof the cortical bone and migration of adjacent teeth(Chart I, next page).

Primordial CystThe primordial cyst comprises approximately 2% of

all odontogenic cysts. It arises from a tooth germwhich, instead of forming a tooth, degenerates into acyst. Clinically this lesion is always associated with amissing tooth. The mandible is involved much morefrequently than the maxilla and the lesion most fre-quently occurs during the second decade of life. Thelesion is generally asymptomatic unle~ it is secondar-ily infected. Most frequently the lesion causes expan-sion of the cortical plates of bone and may producemigration of adjacent teeth. The teeth in the area aregenerally vital. Radiographic examination reveals a

424 RADIOLOGY/ORAL PATHOLOGY IN CHILDREN: Cherrick

PEDIATRIC DENTISTRY: Volume 3, Special Issue 2 425

well-delineated area of radiolucency generally sur-rounded by a thin radiopaque line. The cyst is gener-ally not associated with an erupted or uneruptedtooth. Treatment is surgical removal.Dentigerous Cyst

Dentigerous cysts comprise 34% o~ all odontogeniccysts. They are slightly more common in males than infemales and usually occur in the second decade of life..About 70% of the lesions occur in the mandible and30% in the maxilla. Two-thirds of these cysts occur inthe molar area, generally occurring around an im-pacted mandibular third molar. The maxillary cuspidis the second most frequently involved tooth. The den-tigerous cyst develops after the crown of the tooth iscompletely developed. The enamel origin surroundingthe crown of the tooth undergoes cystic degenerationand the cyst enlarges by an increase in the osmoticand hydrostatic pressure. Radiographic examinationshows an unerupted tooth with a cyst around thecrown.: These cysts are generally aggressive and canencompass the whole ramus and body of the mandible.On rare occasions the cystic lining of the dentigerouscyst may undergo malignant transformation or maytransform into tumors of salivary gland or odonto-genic origin. Clinically these cysts cause expansion ofthe cortical pla~es of bone and, if large enough, causemigration of adjacent teeth. Occasionally, when secon-darily infected they may be extremely painful. Treat-ment is surgical removal.

The dentigerous cyst has a propensity to developaround the crowns of impacted third molars. Theclinical problem 0f dealing with impacted third molarshas been debated for many years. These cysts, whenoccurring in the adult, can frequently cause fracturesOf the mandible. It is good clinical practice to identifyimpacted third molars and remove them as soon aspossible. The propensity to develop dentigerous cystsand the possibility of this cystic lining to develop intoother tumors makes it imperative to remove them assoon as possible. The radiographic demonstration ofthe third molar should be begun at puberty. If it is de-termined clinically that this tooth will not erupt intothe oral cavity it should be moved as soon as possible.A follow-up radiograph should be taken to determinethat the cyst has been completely removed and that aresidual cyst has not developed.

Eruption Cyst. The eruption cyst is a specializedform of a dentigerous cyst. It is generally seen in asso-ciation with the eruption of the primary dentition. Itmost frequently occurs associated withan anteriortooth. Clinically a bluish, compressible, fluid-filled en-largement of the alveolar ridge is noted in an area ofan erupting tooth.

Apical Periodontal CystThe apical periodontal cyst is usUally asympto-

matic. Occasionally when the nonvital tooth becomesinfected this cyst may create a draining fistula andmay also cause pain. This cyst is always associatedwith a nonvital tooth which frequently may be darkerin color than adjacent teeth. The patient will alwaysgive a history of pain in the infected tooth. Ra-diographically, the apical periodontal cyst is charac-terized by a clearly demarcated radiolucency associ-ated with the apical area of the affected tooth. Thelesion varies in size but generally is less than a centi-meter in diameter. Radiographically, it is impossibleto differentiate between an apical periodontal cystand a periapical granuloma. The cystic epitheliumderives from the rests of Malassez. The redicular cystmay be treated in several ways. The most commonmanner is endodontic therapy with apical currettage.Many people believe that unless the epithelium is sur-gically removed the cyst will not disappear.

Odontogenic KeratocystThe odontogenic keratocyst is one of the most ag-

gressive of all the cysts occurring in the jaws. Its nameis: derived from the production of keratin from thecystic epithelium. It should be remembered that theodontogenic keratocyst is a feature of the basal cellnevus syndrome. The peak incidence of the odonto-genic keratocyst isin the second decade and decreasesas the patient gets older. It occurs with equal fre-quency in both sexes and 65% of the reported .caseswere found in the mandibular third molar region.There is a tendency for multiple cysts to occur in a pa-tient. Radiographically, the odontogenic keratocystcannot be distinguished from other intrabony cysts.On occasions its lumen, densely filled with keratin,will cause the usual-radiolucent-like image to have ahazy appearance. Occasionally the margins of the cystwill appear scalloped. It should be remembered thatthe odontogenic keratocyst recurs approximately 40%of the time. Clinically there is generally expansion ofthe buccal cortical plate. There is often crepitous asso-ciated with this lesion. When an odontogenic kerato-cyst has been identified it is incumbent upon the clini-cian to follow these patients with diagnostic radio-graphs every six months. Several incidences of neo-plasms have been reported to develop in the odonto-genic keratocyst.

Keratinizing and Calcifying Odontogenic CystApproximately 25% of the keratinizing and calcify-

ing odontogenic cysts reported have occurred in chil-dren. This unique odontogenic lesion is a cross be-tween a cyst and a neoplasm. Approximately 70% ofthe reported cases have occurred in the mandible andapproximately 75% have been reported to occur cen-trally in bone. Radiographically, the intrabony lesionsappear as a radiolucency, with variable amounts of

426 RADIOLOGY/ORAL PATHOLOGY IN CHILDREN: Cherrick

calcified radiopaque material scattered throughoutthe radiolucency, ranging from tiny flects to largemasses. These lesions have been reported to becomevery large, reaching up to 6 cm in diameter. There isusually buccal cortical expansion of bone. Occasionallythese lesions become secondarily infected and presentwith pain. The treatment for this lesion is surgicalremoval.

Dental Lamina Cyst of the NewbornThe dental lamina cyst of the newborn are multiple

nodules on the alveolar ridge of newborn or veryyoung infants which represent cysts originating fromreminiscence of the dental lamina. Clinically thesecysts present as small discrete white swellings of thealveolar ridge, sometimes appearing blanched asthough from internal p~essure. Radiographs are not in-dicated as these lesions have no osseous involvement.

Non-Epithelial Cysts (pseudocysts) Two non-epithelial cysts are seen which are most

frequently found in the jaws of children. The trau-matic bone cyst constitutes about 13% of the non-odontogenic cysts that occur within the jaws. It isusually seen in individuals under the age of 20 andmales are much more frequently affected thanfemales. The lesion is generally asymptomatic andabout 50% of the cases produce enlargement of thejaws. The area most frequently affected is between themandibular cuspid and the ramus. The teeth withinthe area are vital. The radiographic features of thetraumatic bone cyst are unique. The cyst consists of alarge radiolucency which scallops between the roots ofthe teeth. The teeth in the area are generally vital.There is usually a history of trauma to the area. Uponexploration of this cystic cavity, the lesion is eitherfound to be empty or filled with a clear to blood-stained fluid. The treatment is to create hemorrhage.

The aneurysmal bone cyst is not lined by epithe-lium and is therefore not a true cyst. It occurs mostfrequently under the age of 16 and usually there is ahistory of trauma. Usually the lesion occurs in themandible and there is often a firm, nontender enlarge-ment of the affected area. The overlying mucosa isgenerally normal. Radiographically, the lesion is mul-tilocular and often produces a soap bubble appear:ance. The lesion generally produces expansion of thecortical plates of bone. This lesion frequently displacesteeth but rarely causes root resorption. The treatmentis surgical removal.

Tumors of Odontogenic OriginTumors of odontongenic origin are those tumors

that are derived from the dentai apparatus. Althoughall of the tumors of odontogenic origin occur in chil-dren, the tumors which predominantly occur under

the age of 20 will be discussed in this presentation.(Chart I!, p 428).

Adenomatoid Odontogenic TumorThe adenomatoid odontogenic tumor is derived

from odontogenic epithelium. This tumor occurs pri-marily in teenagers. Females are affected approxi,mately twice as frequently as males. Clinically thelesion presents as a painless, slow-growing expansilelesion of bone. The maxilla is involved twice as com-mon as the mandible. Approximately 75% of the le-sions occurring in the maxilla occur .in the cuspidregion. Three-quarters of the reported cases have oc-curred associated with impacted teeth and are mostfrequently misdiagnosed as dentigerous cysts. Thetumor is most frequently asymptomatic. Radiographi-cally the lesion usually presents as a solitary cystic-appearing lesion associated with an impacted tooth.Frequently calcifications are seen in association withthe tumor, producing a faintly detectable radiolu-cency. The lesion rarely penetrates the cortical plateof bone. Treatment is extraction of the tooth and re-moval of the offending tumor mass.

Ameloblastic FibromaThe ameloblastic fibroma is a mixed odontogenic

tumor composed of both epithelial and mesenchymalelements. The ameloblastic fibroma occurs predomi-nantly in younger patients with the average ageapproximately 141/2. The mandible is more frequentlyinvolved than the maxilla and there is a propensity forthis tumor to occur in the premolar-molar area. Thetumor is associated with an impacted tooth 75% of thetime. There does not appear to be any sex predilec-tion. Clinically the lesion is a slow-growing masswhich is generally asymptomatic. The lesion usuallycauses enlargement of the jaw with occasional migra-tion of the teeth. Radiographic examination shows amultilocular radiolucency with displacement of teeth.Generally the impacted tooth associated with thislesion is pushed to the inferior border of the man-dible. Treatment of the ameloblastic fibroma is con-servative and curettage appears to give an adequatecure rate. Larger lesions have been treated with mar-ginal resection.

OdontomaThe odontoma is the most common of all odonto-

genic neoplasms. The odontoma is derived from bothodontogenic epithelium and mesenchymal componentsof the tooth germ. Odontomas are typically subclassi-fled into compound and complex types. The complextype is composed of a mass of irregularly arrangeddentin, enamel, cementum, and connective tissuearranged in a disorganized pattern not resembling nor-mal tooth morphology. The compound variety is corn-

PEDIATRIC DENTISTRY: Volume 3, Special Issue 2 427

42E, RADIOLOGY/ORAL PATHOLOGY IN CHILDREN: Cherrick

posed of tooth-like structures arranged in an organ-ized pattern resembling small teeth. The compoundvariety is more common than the complex variety, andis usually seen in the maxilla. The complex odontoma,on the other hand, is more common in the mandibleand approximately 70% of these tumors are located inthe second and third molar areas. The most commoncomplaint of a patient with an odontoma relates tothe delayed eruption of a permanent tooth. The ma-jority of odontomas are diagnosed under the age of 15.The lesions are nonaggressive but may reach sizes upto 3 cm in diameter. The treatment for the odontomais enucleation and curettage.

MyxomaThe myxoma is thought to derive from odontogenic

mesenchymal tissue. The tumor frequently occurs in aregion of an unexplained missing tooth which strength-ens the opinion that in these instances the tumor mayhave originated from the dental papillae of the abor-ted tooth bud: Clinically the myxoma presents as aslowly enlarging painless expansion of the jaws and as-sociated migration of adjacent teeth. There is occa-sionally numbness of the lip associated with this lesionwhen it occurs in the mandible. This tumor occursmost frequently in the molar-premolar region of themandible and frequently the ramus is also involved.Root resorption occurs in approximately 60% of thesecases. The peak incidence of this neoplasm is in themiddle teens. The myxoma is considered to be one ofthe most aggressive odontogenic neoplasms. Femalesare affected slightly more often than males. Radio-graphically, the lesion presents as a multilocularradiolucency or as a soap bubble radiolucency. Thetumor borders may be well-defined or poorly delineatedradiographically. It is not uncommon for the lesion toshow scalloping and interdigitation between the teeth.Treatment for this tumor is surgical resection.

Melanotic Neuroectodermal Tumor of InfancyThe melanotic neuroectodermal tumor of infancy is

known by many names (retinal anlage tumor, anlagetumor, progonoma, and pigmented ameloblastoma)each of which refers to a different theory of origin.Currently the tumor is thought to be derived fromneuroectoderm. This tumor occurs in most instancesduring the first six months and is much more com-monly seen in females than in males. The maxilla isthe most common site of occurrence with more than80% of the reported cases occurring in the anteriorportion of the maxilla. The tumor is a relatively rapidgrowing mass. The overlying mucosa is generally in-tact and 75% of these lesions exhibit pigmentation.Often the teeth, in association with the tumor, appearto be floating in space and a differential diagnosis ofhistiocytosis X is therefore entertained. The tumor

mass should be enucleated and curetted as soon aspossible inasmuch as these tumors have a propensityto reach a very large size.

Neoplasms Occurring in Bone

There are four primary neoplasms that affect thejaw bones of children. There are many neoplasms thatare of soft tissue origin that eventually invade bone. Itis not the purvue of this discussion to discuss thoselesions (Chart III, p 430).

Osteogenic SarcomaThe osteogenic sarcoma is the most common pri-

mary malignancy of bone and is a highly malignantneoplasm with the potential to cause extensive de-struction within the jaws with eventual metastasis.Males developing the lesions outnumber females andthe peak occurrence is in the third decade, although25% of the lesions occur before the age of-15. Fre-quently there is a history of previous irradiation or apre-existing bone disorder or trauma to the jaws. Thelesion occurs much more frequently in the mandiblethan in the maxilla. The initial presenting symptom isa lump or swelling in the jaw with pain being the sec-ond most common symptom. Other clinical symptomsare loose teeth, paresthesia, and nasal obstruction.Radiographically, the lesion may present as a radio-lucency, mixed radiolucency and radiopacity, or a ra-diopacity. The typical "sun-ray" appearance is a.rareoccurrence in the jaws. The most commonly seen ra-diographic picture is an increased thickening of theperiodontal membrane space. The prognosis is betterfor jaw lesions than when they occur in the long bones.The five-year survival rate for jaw lesions is approxi-mately 25%. Treatment is surgical resection.

Ewings SarcomaEwings sarcoma is a highly malignant tumor occur-

ring primarily in the second decade of life. It producespain, swelling, or both, and characteristically, the pa-tient appears ill, with low-grade fever, moderate leu-kocytosis and sometimes secondary anemia. Traumais frequently a precurser to this disease. Clinically, thejaw lesions present as a bony, hard expansion with anexceptionally fast growth rate. Occasionally ulcerationis present and there is frequently secondary infection.The mandible is more frequently involved than themaxilla and the lesion is seen more frequently in malesthan in females. The radiographic appearance isextremely variable and nonspecific. The lesion will fre-quently present as an onion-skin layering of subperios-teal new bone. The most common radiographic ap-pearance in the jaws is that of osteolytic mottleddestruction of bone associated with bone expansionand soft tissue swelling. The tumor is radiosensitive,but even with the radical treatment of excision, pre-

PEDIATRIC DENTISTRY: Volume 3, Special Issue 2 429

430 RADIOLOGY/ORAL PATHOLOGY IN CHILDREN: Cherrick

ceded and followed by radiation therapy, the prog-nosis is poor and the number of patients who survivethree years is small. The lesion metastasises early andproduces widespread dissemination.

Histiocystosis XHistiocystosis X includes eosinophilic granuloma,

Hand-Schuller Christian disease, and Letterer-Siwedisease which may represent individual entities or re-flections with a spectrum of disease. In either case it isnow accepted that these histiocystosis have in com-mon a proliferation of a unique histiocyte, the langer-hans’ cell. The pathogenesis and etiology of histio-cystosis X remains obscure.

It is generally conceded that eosinophilic granu-loma, which occurs primarily in bone, has a benigncourse. The term Hand-Schuller Christian disease andLetterer-Siwe disease are best not considered in otherthan clinical terms, since there is no specific histo-pathology associated with these syndromes. A minor-ity of patients with histiocystosis X demonstrate theclassical clinical triad of skull lesions, exophthalmos,and diabetes insipidus. Most patients are children andin some series there is a predominance of males. Clini-cally the initial signs and symptoms of histiocystosisX are oral in 27% of the cases. Jaw involvement isoften manifested as a swelling or ulceration of the gin-giva associated with mobility and loss of teeth withradiographic evidence of alveolar bone resorption. Softtissue involvement may occur without osteolytic le-sions, however, osteolytic lesions are often encoun-tered without associated soft tissue involvement.

Central Giant Cell GranulomaThe central giant cell granuloma is an aggressive

bony lesion that occurs in.young adults with the peakincidence occurring at the end of the second decade.The lesion usually presents as a swelling or expansilelesion within bone and is commonly associated with asensation of increased pressure or pain. The classic ra-diographic appearance is that of a soap bubble, honey-combed, or multilocular central osseous radioluCency.The cortical bone may be eggshell thin and the lesionappears to affect the jaw anterior to the molars muchmore frequently than the posterior jaws. The man-dible is affected in better than three-quarters of thecases. Occasionally the lesion may perforate the corti-cal plates, mimicking an aggressive malignant neo-plasm. Giant cell granulomas of the jaws have beenconsidered to be reactive lesions and not true neo-plasms with malignant potential. Several giant cellgranulomas of the jaws have been seen to be extremelyaggressive. The central giant cell granuloma is themost common multilocular radiolucency of the jaws.Treatment is surgical removal.

Fibro-Osseous LesionsOssifying Fibroma

The ossifying fibroma is a distinct entity of un-known etiology. Oftentimes the cementifying fibromais classified with the ossifying fibroma, although thecementifying fibroma is thought to have its originfrom the periodontal membrane space. The lesions aremost often distributed equally between the maxillaand mandible, although there seems to be a distinctpaucity of the lesions reported in the anterior maxilla.A large percentage of ossifying fibromas are found inintimate relationship to the roots of teeth or in theperiapical regions of the jaws. Large lesions generallycause expansion of the cortical plates. There can begreat variation in the radiographic features of the os-sifying fibroma ranging from totally lytic lesions withvarying amounts of radiopaque calcific loci to lesionsthat are totally radiopaque. Radiographically the le-sions are generally well-circumscribed and this featureseparates them from fibrous dysplasia. The lesionmost frequently occurs in. the later teens or earlytwenties. Treatment is enucleation and curettage.(Chart IV, p 428).

Fibrous DysplasiaFibrous dysplasia is a disease of unknown etiology.

The disease generally infects the jaws as a monostoticlesion although polyostotic forms occur less fre-quently. Clinically the lesion presents as a painless en-largement of involved bones. The maxilla is muchmore frequently involved than the mandible and thelesion generally occurs at puberty. Characteristicallythe maxillary lesions appear to have a~ radiographicappearance of ground glass or an "orange peel" radio-pacity. The borders of the lesions are difficult to de-fine which separates this lesion radiographically fromossifying fibroma. It should be noted that numerouscases of sarcoma have been reported developing in fi-brous dysplasia. More recent studies have shown thatthistendency occurs following radiation therapy.Treatment is generally limited to cosmetic reduction.

¯ TraumaTrauma to the teeth and facial bones may cause

underlying pathology which may not be physicallyevident. Radiographic examination is most importantto determine the extent of injuries. ,Follow-up radio-graphs are usually necessary if there is a diagnosis ofunderlying pathology.

Trauma to TeethTrauma to the teeth may produce clinical fracture

or underlying osseous pathology. It is most importantto take radiographs of the involved area to determinethe extent of damage. Radiographs are important to

PEDIATRIC DENTISTRY: Volume 3, Special Issue 2 431

determine if the pulp is involved during a fracture of atooth. Frequently when there is trauma to the teeththe soft tissues are hemorrhagic and swollen and maynot reveal alveolar fractures or extrusion of the in-volved teeth. It is most important to take diagnosticradiographs in the area of trauma and to follow thehealing process radiographically. Follow-up radio-graphs should be taken if there are any deliberationsregarding delayed healing.

Trauma to the Jaws or Facial BonesTrauma to the jaws or facial bones may cause dislo-

cation of the jaws and or fractures. Dislocation of thetemporomandibular joint occurs when the head of thecondyle moves anteriorly over the articular eminenceinto a position such that it cannot be returned volun-tarily to its normal position. Clinically, luxation ischaracterized by a sudden locking and immobilizationof the jaws when the mouth is open, accompanied by

prolonged spasmodic contraction of the temporal, in-ternal pterygoid, and masseter muscles, with protru-sion of the jaw. All activities requiring motion of themandible, such as eating or talking, are impossible;the mouth cannot be closed and the patient frequentlybecomes panicky. Ofttimes luxation of the jaw maymimic a fracture. It is most important to radiographi-cally investigate injuries or luxation of the condylewhen a patient complains of a sudden change in occlu-sion or to symptoms related above.

Trauma to the facial bones frequently causes frac-tures which are clinically not evident. Whenever sig-nificant trauma has occurred to the facial bones it isimperative that the clinician take radiographs of theaffected area. Most often a good clinical examinationwill reveal the underlying pathology.

Dr. Cherrick is dean, University of Nebraska College of Dentistry,40th and Holdrege Streets, Lincoln, Nebraska C~583. Requests forreprints should be sent to the author.

432 RADIOLOGY/ORAL PATHOLOGY IN CHILDREN: Cherrick