943

Cystic Lesions of theMaxillomandibular Region: MRImaging Distinction of OdontogenicKeratocysts and Ameloblastomas fromOther Cysts

Manabu Minami1TakaShi Kaneda2

Kaoru Ozawa2HimotSugu Yamamoto3

Yuji ltai4Mitsuhisa Ozawa2Kohki Yoshikawa1

Yasuhito Sasaki1

Received February 13. 1 995: accepted after re-vision November 14, 1995.

1 Department of Radiology, University of Tokyo

Hospital, 7.3-1 Hongo, Bunkyo-ku, Tokyo 113, Ja-

pan. Address correspondence to M. Minami.2Department of Radiology, Nihon University of

Dentistry. Matsudo, Japan.

3Department of Pathology. Nihon University of

Dentistry, Matsudo, Japan.

4Department of Radiology, University of Tsuku-

ba Hospital, Tsukuba, Japan.

0361 -803X/96/1 664-943(: American Roentgen Ray Society

OBJECTIVE. Differentiating odontogenic keratocysts and ameloblastomas fromother cystic lesions in the maxillomandibular region is important because of theirhigh recurrence rates. Conventional radiography, CT, and fine-needle aspiration

biopsy are limited for differential diagnosis. The purpose of this study was to reviewthe MR findings in patients with odontogenic keratocysts, ameloblastomas, and othermaxillomandibular cysts to determine the value of MR imaging in the differential diag-nosis of these lesions.

SUBJECTS AND METHODS. MR images were obtained in 38 patients with 43 cysticlesions of the maxillomandibular region. All the lesions (19 odontogenic keratocysts,11 ameloblastomas, five primordial cysts, five radicular cysts, and three cysts ofother types) were pathologically confirmed by surgery or biopsy. Contrast-enhancedMR studies were performed in 34 patients. Images were reviewed to determine van-ous imaging parameters: loculanity, solid on cystic pattern, thickness and contrastenhancement of the walls, and homogeneity and signal intensities of the fluids. T2relaxation times of cystic components were calculated in 31 lesions.

RESULTS. MR Images of odontogenic keratocysts showed that the cysts were unilocu-Ian in 10 lesions and multilocular in nine. In 10 lesions the cyst wall was uniformly thinand had poor contrast enhancement. Seven cysts had thick walls and twohad no definitewalls. In 17 lesions, the cystic contents showed heterogeneous signal intensity on Ti-weighted images, T2-weighted Images, or both. Eight cysts had predominantly Intermedi-ate or high Ti-weighted signal Intensity, and six cysts had predominantly intermediate T2-weighted signal intensity. MR findings in ameloblastomas were different from those inodontogenic kenatocysts: a mixed solid and cystic pattern (ii lesions), irregularly thickwalls (ii lesions), papillary projections (seven lesions), and strong enhancement of solidcomponents (nine lesions). T2 relaxation times of cystic components were significantlyshorter in odontogenic kenatocysts than in ameloblastomas, with no overlap. All othercysts showed a unilocular, purely cystic pattern, with homogeneous fluids, although theT2 relaxation times of four lesions overlapped those of odontogenic kenatocysts.

CONCLUSION. From the MR findings of the walls, solid components, and the fluidcontents, odontogenic keratocysts could be differentiated from ameloblastomas In allcases, although some other cysts showed MR findings similar to those of odontoge-nic keratocysts.

AJR i996;i66:943-949

An expansile radiolucent lesion with no calcified matrix (a so-called cystlike lesion)on plain madiographs of the jaw suggests many diagnoses, such as odontogeniccysts, nonodontogenic cysts, cystic neoplasms, and inflammatory granulomas [1 , 2].Among them, odontogenic kematocysts, which contain kematinaceous material, andameloblastomas, which are benign cystic neoplasms, have high recurrence mates [1,3]. Therefore, preoperative diagnosis has important therapeutic considerations, andneedle aspiration biopsy is done commonly on an outpatient basis. However, theaccuracy of the needle biopsy in oral lesions has been reported to be about 80% [4,

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944 MINAMI ET AL. AJR:166, April 1996

5]. For example, the finding of kematinizing squamous epithe-hum obtained by needle biopsy may pose a problem in differen-tiating among odontogenic keratocysts, cystic acanthomatousameloblastomas, and dentigerous cysts with keratinization [6].We describe the MR findings and differential diagnosis of themaxillomandibulam cystic lesions, with special focus on odonto-genic keratocysts.

Subjects and Methods

Thirty-nine patients in whom plain radiographs showed relativelywell-circumscribed radiolucent lesions 1 .5 cm or larger in diameter inthe mandible or maxilla were examined consecutively by MR imaging.Patients who had lesions with a calcified matrix on plain radiographswere not included in this study. Among the 39 patients, one showed

severe artifacts from dental fillings on MR images, so evaluating thelesion was impossible. The following analysis was obtained from theremaining 38 patients. Subjects included 22 men and 16 women (agerange, 14-68 years old; mean age, 30 years old). Forty-three cysticlesions were included. Thirty-nine were treated by surgery after nee-die biopsy. The other four, diagnosed as odontogenic keratocysts bybiopsy, were followed up without surgery. All pathologic specimenswere evaluated by a specialist in oral pathology. The lesions included

19 odontogenic keratocysts in 15 patients (including four recurrentcases), 11 ameloblastomas in 11 patients (including one recurrentcase; 10 cases had been reported [7]), and 13 other kinds of cysts in12 patients (five primordial cysts, five radicular cysts, one dentigerouscyst, one simple bone cyst, and one recurrent dermoid cyst). One ofthe three patients who had basal cell nevus syndrome had four odon-togenic keratocysts. Another patient who did not have the syndromehad two odontogenic keratocysts. One patient had a primordial cystand a radicular cyst.

Low-field-strength MR scanners were used to reduce unexpectedartifacts caused by dental fillings, which lowered spatial resolution.Thirty-four patients had MR examinations performed on a 0.064-Tpermanent magnet system with a belt neck coil (Toshiba America

MRI, San Francisco, CA). Axial Ti-weighted images were obtainedusing a three-dimensional Fourier transformation and gradient-

recalled echo technique. The imaging parameters were 68/24 (TA!

TE), 45#{176}flip angle, one acquisition, 256 x 256 matrix, 1.1 x 1 .1 mmpixel size, 3.5-mm section thickness, and 32 sections. Contiguousaxial proton density- and T2-weighted images were acquired withspin-echo techniques. The imaging parameters were 1500/30, 105,three acquisitions, 192 x 256 matrix, 1 .1 x 1 .1 mm pixel size, and 10

5-mm-thick sections. In the other four patients, MR imaging was per-formed on a O.2-T permanent magnet system with a head coil (Sie-mens-Asahi Meditech, Tokyo, Japan). The imaging parameters for Ti-weighted images were 363/20, two acquisitions, 256 x 256 matrix,300 x 300 mm field of view, 7-mm section thickness, and an 8.4-mmsection interval. The imaging parameters for T2-weighted imageswere 3000/i 20 and one acquisition; other parameters were identicalto those ofthe Ti-weighted images. In the 35 patients examined mostrecently (32 examined by the 0.064-T scanner and three patients bythe 0.2-T scanner), enhanced axial Ti-weighted images were alsoobtained with the same sequence and at the same position as theunenhanced axial Ti-weighted images, immediately after IV injectionof iO ml (5 mmol) of gadopentetate dimeglumine (Nihon Schering,Osaka, Japan). Subsequently, enhanced coronal or sagittal Ti -

weighted images were obtained with the same pulse sequence asthat of the axial Ti -weighted images.

All MR images were evaluated independently by two radiologistswith regard to the location, locularity, solid and cystic components,features of the walls of the cystic components, contrast enhance-ment of the lesions, signal intensity of the fluids, and presence ofexpansile features and cortical perforation (or probable soft-tissueinvasion). The degree of signal intensity was compared with that ofnormal structures: subcutaneous fat (high intensity) and muscle (lowintensity) on Ti-weighted images, and CSF (high intensity) andmuscle (low intensity) on T2-weighted images. Final decisions werereached by consensus. For the latest 31 lesions studied with the0.064-T scanner, T2-relaxation-time images were calculated from

the proton density-weighted images and the T2-weighted images.The region of interest was set at the cystic component of the lesionon the T2-relaxation-time images with reference to the enhancedaxial Ti -weighted images, and the mean and SD of the T2 relax-ation times and the variation coefficient (ratio of SD to mean T2relaxation times) of cystic contents were obtained. In other lesions,raw data were not available to calculate T2 relaxation times.

Results

Table 1 summarizes the MR findings of odontogenic kera-tocysts, ameloblastomas, and other cysts.

Among 1 9 odontogenic keratocysts, MR images of 13lesions (68%) showed a purely cystic pattern without solid

components, four showed a mixed pattern of solid and cysticcomponents, and the other two looked like solid tumors withno distinct walls or septa. However, the solid components inthe six lesions did not show distinct enhancement and werediagnosed pathologically as keratinized debris in the cavity.The walls and septa of 10 lesions (53%) were uniformly thin,being less than 3 mm thick. Seven lesions had wails thickerthan 3 mm, and the thickness was generally uniform in threeand irregular in four. These walls and septa showed weakenhancement on enhanced MR images, although the degreeof enhancement was not as strong as that of ameloblastoma.The contents were heterogeneous in intensity on Ti -weightedimages only, T2-weighted images only, and both, in six, three,and eight lesions, respectively (Figs. 1 and 2). Two lesionsshowed homogeneous intensity on both images. Cortical per-fomation was identified with suggestion of soft-tissue invasionin seven cases, but all of them showed inflammatory changeswith no soft-tissue invasion pathologically.

All ii ameloblastomas showed a mixed pattern of solidand cystic components and irregularly thick walls. Seventumors (64%) had papillary projections on the walls. Among10 lesions examined by enhanced studies, nine showedstrong enhancement of solid components including walls,septa, and papillary projections (Fig. 3). The cystic compo-nents of all lesions were homogeneously hypointense on Ti -

weighted images and hyperintense on T2-weighted images.Four of eight lesions that showed cortical perforation hadsoft-tissue invasion.

All other kinds of cysts (n = 13) showed a uniloculam cysticpattern without solid components. The walls were uniformlythin and poorly enhanced in eight lesions. Four lesions (twoprimordial cysts and two radiculam cysts), all of which were

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Odontogenic AmeloblastomaKeratocyst

(n=19) (n=il)

Other Cystsa(n= i3)

1 410 9

2 139 0

0 i3ii 0

0 0

0 9ii 4

8

i342

10

17oc 9c

2 ii i3

i7 0 0

7 11 96 0 22 0 24 0 0

ii ii 97 8 i

alncludes five primordial cysts, five radicular cysts, one dentigerous cyst, one simple bone cyst, and one

dermoid cyst.bEvaluated in 17 lesions of a purely cystic or mixed solid and cystic pattern.CEnhanced study was not done in two odontogenic keratocysts, one amelobiastoma, and one radicular cyst.

AJR:166, April 1996 MR OF MAXILLOMANDIBULAR CYSTS 945

TABLE 1 : MR Findings of 43 Cystic Lesions In the Maxillomandibular Region

Lesion Characteristic

LocationMaxilla iiMandible 8

Locularity

Unilocular 10

Multilocular 9

Pattern

CysticMixedSolid

Walls of cystsThin

ThickEnhancement of walls

WeakStrong

Contents of cystsHomogeneousHeterogeneous

Signal intensities on Ti -/T2-weighted imagesLow/highIntermediate or high/highIntermediate or high/intermediateLow/intermediate

Expansile featuresCortical perforation

severely inflamed, had walls more than 3 mm thick andshowed strong enhancement on enhanced Ti -weightedimages (Fig. 4). The other lesion, a madiculam cyst, showeduniformly thick walls more than 3 mm thick, but no enhancedimage was obtained. The contents of all i 3 cysts were homo-geneous in intensity, although two lesions (one primordialcyst and one madiculam cyst) showed high Ti - and T2-weighted signal intensity and two primordial cysts showedintermediate or high Ti -weighted and intermediate T2-weighted signal intensity. One lesion with cortical perforationshowed no soft-tissue invasion.

Mean T2 relaxation times and their variation coefficientswere significantly different among odontogenic keratocysts,ameloblastomas, and other kinds of cysts (Fig. 5). in addi-tion, no overlap was identified in mean T2 relaxation times of

the contents of odontogenic kematocysts and ameloblasto-mas (Table 2). However, mean T2 relaxation times of threeprimordial cysts and one radiculam cyst overlapped those ofodontogenic kematocysts.

Differentiation between cysts and ameloblastomas was pos-sible in 4i lesions (95%) before pathologic diagnosis. The two

misdiagnosed lesions were one infected priniordial cyst andone infected madicular cyst, both of which were diagnosed asameloblastomas because of thick walls with strong enhance-ment. Retrospectively, these walls were uniformly thick and cim-cumferential, unlike the walls of ameloblastomas (FIg. 4). Nomisdiagnosis was made between odontogenic keratocysts andameloblastomas. Preoperative differential diagnosis of variouskinds of cysts was correct in 24 (75%) of 32 lesions accordingto the MR findings described. Among six misdiagnosedlesions, except in the aforementioned two lesions, three pri-mordial cysts and one radicular cyst were diagnosed as odon-togenic keratocysts. The specific diagnosis of one dentigerouscyst and one recurrent dermoid cyst could not be determinedpmeopematively by MR imaging.

Discussion

Odontogenic keratocysts are thought to arise from prolif-emation of residue of the dental lamina and account for 3-ii% of all cysts of the jaw. About two thirds of the cysts arefound in the mandible, with 50% in the third molar-ascend-

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�----w’--�. �

,�‘ �

946 MINAMI ETAL. AJR:i66, April 1996

Fig. 1 .-Unilocular odontogenic keratocyst in22-year-old woman.

A, Panoramic radiograph shows large, uniloc-ular, expansile lesion In right side of maxilla(arrows). Lesion extends into right maxillary ci-nus. Unerupted tooth is seen in lesion. Odonto-genic keratocyst was considered most likelydiagnosis, but unilocular ameloblastoma couldnot be ruled out.

B, Enhanced sagittal Ti-weighted MR Imageshows cystic lesion involving maxillary sinus. En-hanced walls are thin (arrowheads)and somewhatdifficult to evaluate. Signal intensity of cyst Is hat-erogeneous and predominantly intermediate.

C, On axial T2-weighted MR image, fluid con-tents of cyst are heterogeneously intense. Un-erupted tooth is seen in medial side of wall(arrowhead). From these findings, diagnosis ofodontogenic keratocyst was made and enucle-ation was done.

D, Photomicrograph shows cyst has uniform-ly thin wall with keratinization histopathological-ly (H and E, original magnification xlOO).

ing mamus area. The rest occur in the maxilla, usually in the

anterior or anterolateral regions [i , 8-iO]. This entity hasbeen classified as a separate type of maxillomandibulam cyston the basis of its different clinical behavior and unique his-tologic composition: it has an unusually high recurrence rate,reportedly between i 2% and 63% after incomplete surgicalexcision [9]; multiple cysts may occur and are associatedwith basal cell nevus syndrome in about half of such cases[i]; histologically, the wall is composed of a thin, fragile layer

of keratinizing or parakeratinizing stratified squamous epi-

thelium; theme is a well-defined basal cell layer with fewinflammatory cells beneath it; the lumen of the cyst is fre-quently filled with thick, creamy, keratinaceous material [ii,i 2]; and odontogenic kematocysts may arise in other cystssuch as primordial cysts, dentigerous cysts, residual cysts,and lateral periodontal cysts [i , i 3].

Radiologically, odontogenic keratocysts appear as unilocu-lam or multilocular radiolucent lesions, often surrounded by asmooth or scalloped margin with thin sclerosis. The cyst cancause marked cortical thinning and expansion with mild root

resorption. Rarely, its lumen will show a hazy appearancecaused by densely filling keratinaceous materials [8, i4, i5].CT scans of odontogenic kematocysts show three-dimensionalextension, sharply defined borders, and contents of waterdensity [16]. Nevertheless, because of various radiologicappearances of odontogenic keratocysts, many pathologiclesions such as ameloblastomas, primordial cysts, dentiger-ous cysts, residual cysts, aneurysmal bone cysts, traumaticbone cysts, odontogenic myxomas, central giant-cell gmanulo-mas, and cherubism may be included in the differential diag-nosis [i , 2]. Odontogenic kematocysts and ameloblastomasoccurring at the mandibular molam-ramus region have similarappearances [8, 9, i7], and both show expansile or invasivefeatures in the advanced stage [3]. However, their surgicaltreatments differ. A smaller odontogenic kematocyst can betreated by curettage, enucleation, or peripheral osteotomyalone, and a larger lesion frequently needs more aggressivetreatments like marginal or segmental resection because of itshigh recurrence rate [1 8]; ameloblastoma is usually resecteden bloc and sometimes with hemimandibulectomy or partial

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AJR:166, April 1996

Fig. 2.-Multilocular odontogenic keratocystin 21-year-old man.

A, Panoramic radiograph shows large, mul-tilocular, expansile lesion In left molar-ramus re-gion of mandible. Teeth are displaced, and rootsare partly absorbed.

B, CT scan shows multilocular lesion in mandi-ble. Thinned cortex is partly perforated and over-laying masseter muscle was considered invaded.Ameloblastoma was highly suspected from find-ings of radiography and CT.

C, On enhanced axial Ti-weighted MR image,lesion of heterogeneous intensity does not showdistinct enhancement.

D, Axial T2-weighted MR image shows thatfluid contents of cyst are heterogeneous in in-tensity. Odontogenic keratocyst was suspectedfrom MR findings and was proven pathologicallyafter enucleation.

Fig. 3.-Multilocular ameloblastoma in 22-year-old man.A, Panoramic radiograph shows lobulated radiolucent lesion on right molar region of mandible (arrows). No tooth roots are absorbed.B, Enhanced sagittal Ti-weighted MR image shows multilocular lesion with walls and septa of Irregular thickness. walls, septa, and solid portion

(arrows) are strongly enhanced.C, On axial T2-weighted MR image, fluid is homogeneously high in intensity and small solid portion of intermediate intensity can be seen (arrow).

These MR findings suggest ameloblastoma. However, lesion was diagnosed as primordial cyst by fine-needle aspiration biopsy. Curettage was per-formed and specimen was proven to be ameloblastoma.

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Mean ± SD(msec)

Range(msec)

aVU

00

Stajtdaid

Deviation Coefficient

Fig. 5.-T2 relaxation times of cystic contents of 31 cystic lesions.Striped bar = odontogenic keratocysts (n = 14), stippled bar = ameloblas-tomas (n = 7), cross-hatched bar = other cysts (four primordial cysts, fourradicular cysts, one simple bone cyst, and one dermoid cyst), n.s. = notsignificant.

948 MINAMI ET AL. AJR:166, April 1996

Fig. 4.-Infected radicular cyst in 23-year-oldman.

A, Panoramic radiograph shows unilocularradiolucent lesion In left molar region of mandi-ble (arrowheads). Root of third molar Is partlyabsorbed.

B, Enhanced axial Ti-weighted MR imageshows lesion with thick, strongly enhanced wallsof uniform thickness (arrows). Lesion was misdi-agnosed as ameloblastoma at MR Imaging. Patho-logically, radicular cyst was proven from specimenof enucleation.

maxillectomy, because of its neoplastic nature and high recur-mence mate (45-90%) after curettage or incomplete enucle-ation [7, i9]. The findings of infrequent moot resorption andlesser degree of cortical expansion in odontogenic kemato-cysts are reported to be useful for the differential diagnosis[i7, 20], but some authors considered diagnosis impossibleby conventional radiography alone [8, 9].

To our knowledge, MR findings of odontogenic keratocysts

have not been described in detail [2i]. In our study, odontoge-nic kematocysts showed suggestive MR findings: uniformly thinwalls with weak enhancement and fluids of heterogeneous sig-nal intensity. The contents of the cyst frequently showed inter-mediate or high Ti -weighted signal intensity or intermediate

TABLE 2: 12 Relaxation Times of Cystic Contents of 31 Cystic

Lesions

Type of Cyst

Odontogenic kerato- 145 ± 53 57-i 96cyst(n= 14)

Ameloblastoma (n = 7) 258 ± 48 244-283Other cystsa (n = 10) i95 ± 53 i3i-271

alncludes four primordial cysts, four radicular cysts, one simple bone cyst,

and one dermoid cyst.

T2-weighted signal intensity. These findings differed fromthose of ameloblastoma: a mixed pattern of solid and cysticcomponents, irregularly thick walls, papillary projections,homogeneous fluids of low Ti-weighted and high T2-weightedsignal intensity, and marked enhancement of solid portions, aspreviously reported [7]. In addition, T2 relaxation times of thecontents of odontogenic kematocysts were significantly shorterthan those of ameloblastoma. The larger variation coefficient inodontogenic kematocysts also suggests that their fluid is moreheterogeneous than that of ameloblastoma (Fig. 6). Even withMR imaging, however, differentiating odontogenic keratocystsfrom primordial cysts may be difficult, unless the odontogenickeratocyst shows multiloculanty or heterogeneous signalintensity. This differentiation may not be clinically important,

because these two entities are considered synonymous in theclassification by the World Health Organization [22]. We havenot performed MR examinations for the other entities we listed.Aneurysmal bone cysts are reported to show characteristicfluid-fluid levels on MR images [23]. Central giant-cell tumorand cherubism will basically show a solid pattern that isenhanced by contrast agents [24].

In conclusion, odontogenic keratocysts could be differentiatedfrom ameloblastomas in all cases from the MR findings of thewalls, solid components, and fluid contents. T2 relaxation timesof cystic components were also useful in the differentiation.However, some other cysts showed MR findings similar to thoseof odontogenic keratocyst with an overlap of T2 relaxation times.

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AJR:166, April 1996

Fig. 6.-T2-relaxation-time Images.A, Fluid content of odontogenic keratocyst

(same patient as Fig. i) has heterogeneous, shortT2 relaxation times (mean ± SD, 125 ± 32 msec).

B, Fluid content of ameloblastoma has homo-geneous, long T2 relaxation times(252 ± 50 msec).

MR OF MAXILLOMANDIBULAR CYSTS 949

REFERENCES

1 . Hoffman S. Jacoway JR. Krolls SO. lntraosseous andparosteal tumors of

the jaws: atlas of tumor pathology. 2nd ser., fasc. 24. washington, DC:Armed Forced Institute of Pathology, i985;i8-30

2. Eversole LR, Rovin S. Differential radiographic diagnosis of lesions of thejawbones. Radiology 1 972; 105:277-284

3. Hoffman S. Jacoway JR. Krolls SO. lntraosseous and parosteal tumors ofthe jaws: atlas of tumor pathology, 2nd ser., fasc. 24. Washington, DC:Armed Forces Institute of Pathology, i985: 94-112

4. SchOll A, Niemczyk H-M. Cytological tumour diagnosis in maxillo-faciatsurgery examinations using the fine needle aspiration technique. J Maxil-lofac Surg 1980:8:17-24

5. GUnhan 0. Do�an N, Celasun B, SengUn 0, Onder T, Find R. Fine needle

aspiration cytology of oral cavity and jaw bone lesions: a report of 102cases. Acta Cyto/i993;37:135-141

6. Ramzy I. Aufdemorte TB, Duncan DL. Diagnosis of radiolucent lesions ofthe jaw by fine needle aspiration biopsy. Acta Cytol i985;29:4i9-424

7. Minami M, Kaneda T, Yamamoto H, et at. Ameloblastoma in the maxillo-

mandibular region: MR imaging. Radiology 1992:184:389-3938. Browne RM. The odontogenic keratocyst: clinical aspects. Br Dent J

1970:128: 225-231

9. Brannon RB, Colonel L. The odontogenic keratocyst: a clinicopathologicstudy of 312 cases. Part 1: Clinical features. Oral Surg Oral Med OralPathol 1976:42:54-72

10. Hodgkinson DJ. Woods JE, Dahtin DC, Totman DE. Keratocysts of tumorsof the jaw: clinicopathologic study of 79 patients. Cancer i978;41 :803-813

11 . Shear M. Primordial cysts. J DentAssoc SAfri96O;15:211-21712. Pindborg JJ, Philipsen HP, Henriksen J. Studies on odontogenic cyst

epithelium: keratinization in odontogenic keratocysts. In: Butcher EO,Sognnaes RF, eds. Fundamentals of keratinization, PubI. No. 70, wash-

ington, DC: American Association for the Advancement of Science.i 962:151-160

13. Payne TF. Analysis of the clinical and histopathological parameters of theodontogenic keratocyst. Oral Surg Oral Med Oral Pathol 1972:33:538-546

14. Mclvor J. The radiological features of odontogenic keratocysts. Br J Oral

Surg 1972:10:116-12515. Smith I, Shear M. Radiological features of mandibular primordial cysts

(keratocysts). J Maxillofac Surg 1978:6:147-15416. Frame JW, Wake MJC. Computerized axial tomography in the assess-

ment of mandibular keratocysts. Br Dent J i 982; 153:93-961 7. Tanimoto K, Fujita M. Wada T, Koseki T. Fujiwara M. Uemura S. Radio-

graphic features of odontogenic keratocyst in the mandibular ramus: forthe differential diagnosis from ameloblastoma (abstr in English). Dent

Radiol 1982;21 :237-245

18. Williams TP. Surgical treatment of odontogenic keratocysts. Oral Max/b-

fac Surg Clin North Am 1991:3:137-15419. Struthers P, Shear M. Root resorption by ametobtastoma and cysts of the

jaws. lntJ Oral Surg 1976:5:128-132

20. Macintosh RB. Aggressive surgical management of ameloblastoma. OralMaxibofac Surg Clin North Am 199i :3:73-97

21 . Belkin BA, Papageorge MB, Fakitsas J. Bankoff MS. A comparative study

of magnetic resonance imaging versus computed tomography for theevaluation of maxillary and mandibular tumors. J Oral Maxihofac Surgi988;46:1039-1047

22. Kramer IRH, Pindborg JJ. Shear M. Histological typing of odontogenic

tumours: international histological classification of tumours, 2nd ed. Ber-tin: Springer-Verlag, i992:34-38

23. Revel MP, Vanel D, Sigat R, et at. Aneurysmat bone cysts of the jaws: CTand MR findings. J Comput Assist Tomogr i 992:16:84-86

24. Casselman JW, De Jonge I. Neyt L, De Clercq C, D’Hont G. MRI in cran-iofacial fibrous dysplasia. Neuroradiology i993:35:234-237

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21.2

38.1

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n 01

/03/

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rom

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addr

ess

114.

121.

238.

119.

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S. F

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