Editor:

Allan G. Farman, BDS, PhD(odont.), DSc (odont.),Diplomate of theAmerican Board of Oraland MaxillofacialRadiology, Professor ofRadiology and ImagingSciences, Department ofSurgical and HospitalDentistry, The University ofLouisville School ofDentistry, Louisville, KY.

Contributor:

Dr. C.J. Nortjé, BChD, PhD, DSc,Professor and Chairman ofOral and MaxillofacialRadiology, Tygerberg, SouthAfrica, President-Elect of theInternational Association ofDentomaxillofacial Radiology.

Featured Ar ticle:

Pathologic conditions ofthe maxillary sinus

In The Recent Literature:

Oral Cancer

Maxillofacial Trauma

Volume 2, Issue 3 US $6.00

Radiography of the maxillarysinuses is often undertaken usingcomputed tomography, magneticresonance imaging, or theoccipito-mental plain x-ray filmprojection. However the panoramicradiograph has been foundsuperior to the latter for detectionof �cyst-like densities.� [1]. Theoccipito-mental technique, firstdescribed by Waters and Waldron,clearly demonstrates the superior,inferior and lateral margins of themaxillary sinuses while reflectingthe shadows of the petroustemporal bones downwards belowthe inferior margin of the sinuses [2].It also demonstrates well any softtissue or fluid contents of the sinus[1]; however, this method does notdisplay the cortices of the anteriorand posterior wall.

While CT, MRI and the Waters�projection are well suited todemonstrate the maxillary sinuses,these methods are only employedif there are signs and symptoms ofdisease, by which time theprognosis for patients having suchinsidious disease as squamous-cellcarcinoma can be poor [3].Extensive lesions occupying themaxillary sinus can producesurprisingly few clinical features [4].For this reason, the panoramicradiograph can be the primaryindication of maxillary sinusdisease. While panoramicradiography can be used todetect maxillary sinus disease, itcannot be used to entirely excludesinus pathology. Only the portionsof the sinus that are within the

image layer will be demonstrated.As the panoramic image layer mostclosely reflects the dental arch,sinus disease occasionally ariseswithin the sinuses outside the imagelayer.

Diseases of the maxillary sinusare comparatively frequent, even inapparently young individuals � withrates in excess of one in fiveindividuals examined using theWaters� projection (mucosalthickening 12.3%; cysts or polyps7.2%; opacified sinus 3.3%) [5]. Forthis reason, it is incumbent upon thedental practitioner to understandthe panoramic radiological featuresof disease and normal variationswithin the paranasal sinuses.Certainly the patient should not bereferred to an ear, nose and throatspecialist for every instance ofantral mucosal thickening ormucous retention cyst (Fig. 1 &2), norshould the dentist ignore featuresthat possibly reflect an earlymalignancy. The reputation of apractitioner is greatly enhancedgiven appropriate referrals that canmake the difference between lifeand death. Failure to diagnose, onthe other hand, can result innotoriety.

Nortjé et al [3] were among thefirst to comprehensively study theappearance on panoramic dentalradiographs of pathologicalconditions affecting the maxillarysinuses, comparing inflammatoryconditions of dental origin,iatrogenic disease/foreign bodies,non-odontogenic inflammatoryconditions, cysts, benignneoplasms, malignant neoplasmsand dysplasias affecting themaxilla.

Pathologic conditions of themaxillary sinusBy Dr. Allan G. Farman incollaboration with Dr. C.J. Nortjé

“ The early detection of insidious maxillary sinus diseasecan be very important for the patient’ prognosis,especially in the case of malignant neoplasia.”

Chronic abscesses resulted in aloss of the outline of the lowerborder of the sinus where it abuttedthe associated tooth, and a relatedthickening of the sinus mucosa wasoccasionally evident. Radicularcysts (generally associated withthe root apex of a carious orfractured tooth) and residual cystscaused an upward displacementof the floor of the sinus, but thecortical outline remained intact.Extensive dental cysts extendedinto the sinus away from the originalepicenter (Fig. 3). Even a very largeradicular cyst arising in the maxillaresulted in surprisingly little in theway of clinically noticeable jawexpansion. Dentigerous cysts had asimilar effect on the floor of themaxillary sinus to that observed forradicular cysts, however, thedentigerous cyst enveloped thecrown of an unerupted tooth. As thetooth was displaced there was theappearance of a tooth suspendedwithin the sinus.

Odontogenic keratocysts arehomogeneous radiolucencies thatmight be unilocular, crenulated ormultilocular in outline, andoccasionally they envelopeunerupted teeth (Fig. 4). These alsotend to displace the sinus floor andto extend into the sinus whileproducing little in the way of jawexpansion. Benign tumors in generaldisplaced the sinus floor andexpanded into the maxillary sinusrather than outwards (Fig. 5).Trabeculation within multiloculartumors such as the myxoma and theameloblastoma frequentlyobscured the maxillary sinus outline.In comparison with benignneoplasms, malignant tumorsaffecting the portion of the sinusscreened by the plane of thepanoramic radiograph resulted inirregular erosion of bone.

Fig. 1. Mucous retention�cyst�: detail frompanoramic radiograph showsdomed soft tissue density inleft maxillary sinus (arrow).

Fig. 2. Mucous retentioncyst of maxillary sinus(arrow) shown using theoccipito-mental projection(Waters� projection). Thisprojection can be madeusing the cephattachment available foruse with panoramicsystems.

Fig. 3. Radicular cyst on carious rightmaxillary lateral incisor. The lesion is awell-delineated unilocular homogeneousradiolucency. It has grown so large that ithas caused a displacement of theipsilateral anterior wall and floor of themaxillary sinus.

Primary malignancies affectingthe maxillary sinus includesquamous-cell carcinoma,adenoid cystic carcinoma andadenocarcinoma [7]. The maxillarysinus may also be affectedsecondarily by extensionmalignancies of the oral softtissues or jaw, and also, althoughrare, is the site of metastases fromdistant sites [8].

Owing to their radio-opacity,roots or whole teeth displaced intothe sinus are readily apparent evenwhen not centered within theimage layer. These need to bedifferentiated from sinus bonenodules and antroliths (calcified�stones� arising in the antral lining)both of which entities could bemistaken for teeth or displacedroots [9]. Foreign bodies, such asbullets, are clearly demonstrated;however care needs to be made todifferentiate between clearlydemarcated real images, andblurred magnified ghost images offoreign bodies or jewelry moredistally and lower placed in or onthe contralateral side of the face.Oroantral fistulas following dentalextraction are only noticeable onpanoramic radiography when large� and within the panoramic imagelayer.

Regarding inflammatoryconditions of non-odontogenicorigin, these are usually clearlydemonstrated on panoramicradiography if they involve mucosalthickenings arising from the floor ofthe maxillary sinus. The mostfrequent example of such aprocess is the mucous retentionphenomenon. This is seen as asmooth dome-shape swelling ofthe mucosa with homogeneousradiodensity. The sinus floor is notdisplaced or eroded. A mucousretention phenomenon is rarely

Fig. 5. Benignneoplasm,adenomatoidodontogenic tumor:unilocular lesion in theleft maxilla subjacentto the canine tooth(cropped panoramic,occlusal andspecimenradiographs). Notedisplacement ofmaxillary sinus floor(arrow).

Fig. 6. Fibrous dysplasia:cropped panoramic radiographshowing mature (late) lesion ofthe left maxilla, obscuring thesinus. The lesion is radio-opaque with some radiolucentmottling. It has a ground(frosted) glass appearance.The lesion melds with thenormal surrounding bone.

Fig. 4. Odontogenic keratocyst: multiple lesions inboth jaws in nevoid basal cell carcinoma syndrome.The maxillary lesions are unilocular while themandibular lesions are crenulated and multilocular.There is displacement of �enveloped� teeth, someof which apparently �float� in the maxillary sinuses(e.g. arrows).

symptomatic; it requires notreatment. Antral polyps are onlyclearly demonstrated whensituated in the panoramic imagelayer. This is rarely the case;hence, other radiographic viewsare preferred. Opacified sinusesor fluid levels may be found withacute sinusitis, whichaccompanies the commoncold in 0.5-5% of cases [5;6].

The maxilla can also be thesite of a variety of dysplasticand fibro-osseous conditions.Fibrous dysplasia can cause thepartial or complete occlusion ofthe sinus on the affected side ofthe maxilla (Fig. 6). This may arisein young children and is usuallyapparent by adolescence. It isgenerally unilateral. By way ofcomparison, Paget�s disease ofbone can also cause occlusionof the sinus, but can affect bothsides of the maxilla and is foundin an aging population (Fig. 7).Cherubism may affect themaxillary tuberosities bilaterallyas well as the mandibular rami.The lesions are initiallymultilocular radiolucencies andlater sclerose.

Clinical Significance ofMaxillary Sinus DiseaseThe early detection of insidiousmaxillary sinus disease can bevery important for the patient�sprognosis, especially in the caseof malignant neoplasia. By thetime of overt signs of squamous-cell carcinoma of the maxillaryantrum (e.g. neck nodemetastasis or palatal fistula � Fig.8 & 9), the five-year survival isonly one in six [7]. Substantialprogress is being made withmulti-modality treatment ofcancer; hence, the dentist maywell make a difference in

Fig. 8. Late stagemaxillary sinussquamous-cellcarcinomaeroding throughthe palate.Prognosis is poor.This patient hasfixed cervicallymph nodes dueto metastasis.

Fig. 7. Paget�sdisease of bone:Note cotton-ballradio-opaquesclerotic deposits.There is maxillarycortical expansion.The lesion isbilateral, crossingthe midline(panoramic andlateral skullradiographs).

Fig. 9. Squamous-cellcarcinoma: Water�s viewshowing opacification ofleft maxillary antrum(sinus) with destruction ofnasal and orbital walls(arrows).

patient longevity by the earlydetection of cancer from astutereading of the panoramicradiograph [8]. Early detection canresult in an 80%, or better,treatment success rate asdetermined by 5-year survival[10,11]. It has been found thatpanoramic radiography candemonstrate antral malignancy atthe time of diagnosis in 90% ofcases [12]. However, occasionalindividual case reports do showthat, dependent on the lesion�sprecise site, even large squamouscell carcinomas might be missedwhen relying on panoramicradiographs alone [13,14].

The prevalence of mucosalretention cysts in the maxillarysinus averages around 5%, butvaries considerably from report toreport, perhaps as a function ofpopulation, geography and season[15-18]. The prevalence isapproximately twice as high inmen as in women. The detectionand correct interpretation of theretention cyst is important forpreventing unnecessary diagnosticprocedures or surgical intervention[19]. It has been demonstrated thatthe retention cyst, unlike the antralmucocele, has no relationship tosinus obstruction [20]. Antralmucoceles are associated withosteal closure and complete sinusopacification, pain, jaw expansionand erosion of the antral outline [21,22].

When dealing with panoramicradiographs, one needs toconsider the possibility of ghostimages being reflected well awayfrom the actual lesion. This isparticularly the case with highlyradiopaque foreign bodies such asthose associated with gunshotinjuries [23].

SummaryThe growth of tumors within themaxilla is not concentric; hence,the site of origin is not necessarilythe epicenter of the lesion. Themaxillary sinus, or antra,constituted the path of leastresistance for the growth of suchmaxillary lesions as cysts andbenign neoplasms. Even very largebenign tumors and cysts might bepresent without resulting inclinically noticeable jawexpansion. Hence, the panoramicradiograph is of value in detectionof unsuspected disease.

Antral malignancies are usuallyinsidious and produce clinicalsigns and symptoms relatively late,when the prognosis is often quitepoor. Panoramic radiographs havebeen found of utility in detection ofantral carcinoma, particularly thataffecting the posterior wall of thesinus [24]. Caution should be usedin that the panoramic radiograph isnot the technique of choice forviewing the maxillary sinuses �however, it is incumbent on thedentist to evaluate the portion ofthe maxillary sinus shown in thepanoramic radiograph made forother purposes. This might well bethe first sign of disease and theonly reason for pursuing furtherdiagnostic tests. Early detection ofsuch sinister occurrences improvesthe prognosis for the unfortunatepatient.

There are limitations to the useof panoramic radiography in thedetection of maxillary sinusdisease; namely, only the areaswithin the selected image layer willbe in focus. Experimental studieshave shown that axial computedtomography provides a betterevaluation of osteolytic lesions inthe latero-superior or middle of the

References1. Ohba T, Katayama H. Comparison of

panoramic and Water�s projection in thediagnosis of maxillary sinus disease. OralSurg 1976;42:534-538.

2. Waters CA, Waldron CW. Roentgenologyof the accessory nasal sinuses describinga modification of the occipito-frontalposition. Amer J Roentgenol (Detroit)1915;2:633.

3. Nortjé CJ, Farman AG, Joubert JJ deV. Pathological conditions involvingthe maxillary sinus: their appearances onpanoramic dentalradiographs.Brit J OraSurg 1979;17:27-32.

4. Farman AG, Nortjé CJ, Grotepass FW,Farman FJ, van Zyl JA. Myxofibroma ofthe jaws. Brit J Oral Surg 1977;15:3-18.

5. Savolainen S, Eskelin M, Jousimies-SomerH, Ylikoski J. Radiological findings in themaxillary sinuses of symptomless youngmen. Acta Otolaryngol Suppl1997;529:153-157.

6. Lee RJ, O�Dwyer TP, Sleeman D, Walsh M.Dental disease, acute sinusitis and theorthopantomogram. J Laryngol Otol1988;102:222-223.

7. Kim GE, Chung EJ, Lim JJ, Keum KC, LeeSW, Cho JH, Lee CG, Choi EC. Clinicalsignificance of neck node metastasis insquamous cell carcinoma of themaxillary antrum. Am J Otolaryngol1999;20:383-390.

8. Koscielny S. The paranasal sinuses asmetastatic site of renal cell carcinoma.Larungorhinootologie 1999;78:441-444.

9. Jain RK, Frommer HH. Incidental findingof antroliths in panoramic radiography.NY State Dent J 1982;48:530-531.

10. Hayashi T, Nonaka S, Bandoh N,Kobayashi Y, Imada M, Harabuchi Y.Treatment outcome of maxillary sinussquamous cell carcinoma. Cancer2001;15:1495-1503.

11. Tiwari R, Hardillo JA, Mehta D, Slotman B,Tobi H, Croonenburg E, van der Waal I,Snow GB. Squamous cell carcinoma ofmaxillary sinus. Head Neck 2000;22:164-169.

posterior sinus wall than willpanoramic radiograph [25,26].Lesions affecting the floor of themaxillary sinus are better identifiedand localized with panoramic filmsthan with the Waters� projection[27]. When dentists are reading theradiographs, panoramicradiographs have been foundequal to Waters� projection fordetermination of sinusitis [28].These two techniques, andcomputed tomography, should beconsidered complementary ratherthan alternatives [1].

“...the dentist may well make a difference in patient longevityby the early detection of cancer from astute reading of thepanoramic radiograph.”

©2002 Panoramic Corporation (07-02)

12. Epstein JP, Waisglass M, Bhimji S, Le N,Stevenson-Moore P. A comparison ofcomputed tomography and panoramicradiography in assessing malignancy ofthe maxillary antrum. Eur J Cancer OralOncol 1996;32B:191-201.

13. Lillienthal B, Punnia-Moorthy A. Limitationsof rotational panoramic radiographs inthe diagnosis of maxillaryn lesions. Casereport. Aust Dent J. 1991;36:269-272.

14. Haidar Z, Diagnostic limitations oforthopantomography with lesions of theantrum. Oral Surg 1978;46:449-453.

15. Halstead CL. Mucosal cysts of themaxillary sinus: report of 75 cases. J AmDent Assoc 1973;87:1435-1441.

16. Myall RW, Eastep PB, Silver JG. Mucousretention cysts of the maxillary antrum. JAm Dent Assoc 1974;89:1338-1342.

17. Ruprecht A, Batniji S, el-Neweihi E. Mucousretention cyst of the maxillary sinus. OralSurg Oral Med Oral Pathol 1986;62:728-731.

18. MacDonald-Jankowski DS. Mucosal antral

cysts in a Chinese population.Dentomaxillofac Radiol 1993;22:208-210.

19. Bohay RN, Gordon SC. The maxillarymucous retention cyst: a commonincidental panoramic finding. Oral Health1997;87:7-10.

20. Tufano RP, Mokadam NA, Montone KT,Weinstein GS, Chalian AA, Wolf PF, WeberRS. Malignant tumors of the nose andparanasal sinuses: hospital of the Universityof Pennsylvania experience 1990-1997. AmJ Rhinol 1999;13:117-123.

21. Bhattacharyya N. Do maxillary sinusretention cysts reflect obstructive sinusphenomena? Arch Otolaryngol Head NeckSurg 2000; 126:1369-1371.

22. Barsley RE, Thunthy KH, Weir JC. Maxillarysinus mucocele. Report of an unusualcase. Oral Surg Oral Med Oral Pathol1984;58:499-505.

23. Blaschke DD, Sanders B. Radiology ofmaxillofacial gunshot injuries. Oral Surg1979;47:294-299.

24. Greenbaum EI, Rappaport I, Gunn W. Theuse of panoramic radiography indetection of posterior wall invasion bymaxillary antrum carcinoma.Laryngoscope 1969;79:256-263.

25. Perez CA, Farman AG. Diagnosticradiology of maxillary sinus defects. OralSurg Oral Med Oral Pathol 1988;66:507-512.

26. Ohba T, Ogawa Y., Shinohara Y, HiromatsuT, Uchida A, Toyoda Y. Limitations ofpanoramic radiography in the detectionof bone defects in the posterior wallof the maxillary sinus. DentomaxillofacRadiol 1994;23:149-153.

27. Duker J, Fabinger A. Evaluation of thebasal parts of the maxillary sinus bymeans of panoramic tomography. DtschZahnarztl Z 1978;33:823-826.

28. Lyon HE. Reliability of panoramicradiography in the diagnosis of maxillarysinus pathosis. Oral Surg 1973;35:124-128.

In The Recent Literature:Oral cancer: Panoramic radiographyis a useful adjunct in evaluation ofbone invasion by gingival squamouscell carcinoma.Gomez D, Faucher A, Picot V,Siberchicot F, Renaud-Salis JL,Bussieres E, Pinsolle J. Outcome ofsquamous cell carcinoma of thegingiva: a follow-up study of 83cases. J Craniomaxillofac Surg 2000Dec;28(6):331-35. [From the BergonieInstitute, Regional Cancer Center,Bordeaux, France.]

Squamous cell carcinoma of thegingiva is relatively uncommon.Standard treatment involves surgeryand/or radiotherapy. From 1985 to1996, 83 patients with squamous cellcarcinoma of the gingiva weretreated at the Department ofSurgery, the Bergonie Institute and atthe Department of Maxillofacial andPlastic Surgery of the UniversityHospital, Bordeaux, France. Aretrospective review of panoramicradiographs and clinical records wasused to evaluate bone involvement

from the gingival carcinomas.Outcomes were calculated using theKaplan-Meier method. Primary localcontrol was achieved in 72 patients(87%). Overall survival and rate ofrecurrence were comparable to thosereported for other squamous cellcarcinomas of the oral cavity andoropharynx.

Maxillofacial trauma: Panoramicradiographs proved significantly morereliable than mandibular film seriesfor the detection of mandibular jawfractures.Nair MK, Nair UP. Imaging of mandibulartrauma: ROC analysis. Acad EmergMed 2001 Jul;8(7):689-95. [From theDepartment of Oral and MaxillofacialRadiology, University of Pittsburgh,Pittsburgh, USA.]

The objective of this study was tocompare the diagnostic efficacy fordetection of mandibular fractures ofpanoramic radiography versusmandibular trauma series presentedboth as analog and as digitized

radiographs. Fractures were inducedusing blunt trauma to 25 cadavermandibles. Panoramic radiographsand mandibular series comprising anantero-posterior view, two lateraloblique, and a reverse Towne�sprojection were made. Themandibular series was viewed both inanalog and in digitized forms. Sixobservers recorded theirinterpretations using a five-pointconfidence rating scale. The datawas studied using receiver operatingcharacteristic (ROC) curve analysis.Significant differences based onimaging modalities were found (p <0.0015) in the area under the curves(A(z)): mandibular series, 0.75;digitized mandibular series, 0.77,panoramic radiograph, 0.87; andpanoramic plus antero-posteriorradiographs in combination, 0.89. Noobserver-based differences werefound. Intra- and inter-observeragreements were high (kappa(w) =0.81 and 0.76, respectively). It isconcluded that panoramicradiographs are adequate for thedetection of mandibular fractures.The addition of an antero-posteriorview only marginally improveddiagnostic accuracy.

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