J. Nihon Univ. Sch. Dent., Vol.39, No.4, 171-175, 1997

Original A clinicopathologic study of odontomas: Malaysian findings

Kok Han Ng1 and Chong Huat Siar2

Division of Stomatology1, Institute for Medical Research, Jalan Pahang 50588 Kuala Lumpur, Malaysia Department of Oral Pathology2, Oral Medicine and Periodontology Faculty of Dentistry, University of Malaya, 50603 Kuala Lumpur, Malaysia

(Received 21 February 1997 and accepted 22 August 1977)

Abstract: This report reviews the clinico- Odontomas are well-recognized lesions and serial pathologic characteristics of 104 cases of odontomas studies from North America (2,4,6), Australia (8), Chile diagnosed in the Division of Stomatology, Institute for (4) and Turkey (7) have delineated their prevalence and Medical Research, Kuala Lumpur, over a 29-year clinicopathologic characteristics. However, little is period (1967-1995). The results showed no real known of its pattern of occurrence in the Southeast Asian predilection in terms of sex (M: F ratio, 1: 1), race region. In view of this, it seems appropriate to present (45.2 % Malays, 40.4 % Chinese, 10.6 % Indians and our analysis of the 29-year record of all diagnosed cases 3.8 % other races) or site (maxilla: mandible ratio, 1: of odontomas from this department and to compare our 1.04) distribution. The mean age at presentation was findings with similar studies from other geographic 24.8 years and the age range was 3 - 74 years. There areas. were 102 intraosseous and 2 extraosseous odontomas. Swelling was the most common presenting complaint. Materials and Methods The majority of cases (81.9 %) were clinically The biopsy records of the Division of Stomatology, diagnosed as odontomas. The treatment of choice Institute for Medical Research, Kuala Lumpur, were was surgical enucleation. Compound (43.3 %) and reviewed for the prevalence of odontomas. The basic complex (35.5 %) odontomas were the two most criteria used followed definitions and descriptions of common histological types encountered. The present odontomas in common use (1-13). One hundred and findings correlate favorably with reported studies four cases (including one previously reported (9)) were from other geographic areas. found after review. Clinical data with respect to age, gender, race, location, symptoms and treatment were Key words: human; odontoma; histopathology; retrieved from descriptive summaries of biopsy request Malaysians. forms. Radiographs, where available, were also examined to assist in their interpretation. Histologic information was obtained by reviewing hematoxylin and eosin stained Introduction sections of all cases without reference to their original Odontomas are malformations of dental tissues (1). reports. Lesions were subclassified as compound, These lesions are usually diagnosed in the second and complex, mixed, extraosseous/soft tissue odontomas and third decades of life and show an almost even distribution odontomas in association with calcifying odontogenic between the sexes (2-12). Clinically, these patients cyst, based on established criteria (1-13). Supernumerary present with few symptoms and the odontomas are often teeth, gestant odontome and true mixed odontogenic discovered during routine radiographic examination (4- tumors (e.g. ameloblastic fibro-odontoma) were excluded 6). They may occur anywhere in the jaws, showing either from this study. a slight predilection for the maxilla or mandible (6-8). Histologically, several types are recognized, the most Results common being compound (where the dental tissues are One hundred and four cases of odontomas, including arranged in an orderly manner forming many tooth-like one case (9) previously reported from this department, structures) and complex (where the dental tissues occur in were studied. They represented about 2.8 % of all a disarrayed manner) odontomas (1,5,6). The less odontogenic cysts and tumors (based on the WHO commonly encountered variants are the soft tissue or classification (1)) diagnosed in the Division of extraosseous odontomas (9,12) and odontomas found in Stomatology over a 29-year period (1967-95). Their data conjunction with calcifying odontogenic cysts (6). were analyzed according to race, gender, age, site Regardless of their histologic forms, odontomas are distribution, and histologic types (see Table 1). Fifty-one hamartomatous in nature and recurrences are rare. (49.0 %) of the cases occurred in patients younger than 21 years of age. Of these, 40 (38.5 %) belonged to the

Correspondence to Dr. Kok Han Ng, Division of Stomatology, Institute 11-20 age group. Twenty-five of the 104 odontomas were for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia asymptomatic. In the remaining 79 cases, the most 172

Table 1 Race, sex, age, site distribution and histologic types of odontomas in Malaysians

COC - Calcifying odontogenic cyst

Table 2 Demographic characteristics of compound and complex odontomas in Malaysians 173 common presenting symptoms in decreasing order of (examples of these are shown in Figs. 2 and 3). In the frequency were swelling (74.7 %), pain (19.0 %), remaining 25 cases, their radiographic appearances were discharging sinus (19.0 %), ulcer (13.9 %), erupting unknown. Embedded teeth, namely incisors (10.8 %), odontoma (8.9 %), (1.3 %) and paraesthesia canines (8.8 %), third molars (6.9 %), second molars (2.9 (1.3 %). The duration of these symptoms ranged from 3 %) and supernumerary teeth (0.9 %) were also found in days to 10 years (mean duration, 15.5 months). There association with these odontomas. There were no were 102 intraosseous and two extraosseous or soft tissue underlying radiologic changes in the two cases of soft odontomas (one of these cases was previously reported as tissue odontomas studied. an extraosseous odontoma occurring in association with a Data on clinical diagnoses were available in 94 cases. peripheral odontogenic fibroma (9)). Their site Most of these cases (81.9 %) were clinically diagnosed as distribution in the jaws is illustrated in Fig.1. Sixty-six of odontomas. Other less commonly clinically-diagnosed the intraosseous odontomas presented as radiopaque conditions were (6.4 %), dentigerous cysts masses, 11 as mixed radiolucent-radiopaque lesions (4.2 %), osteomas (2.1 %), chronic osteomyelitis (2.1 %),

Fig. 1 Site distribution of 104 cases of odontomas. Fig. 2 Radiographic appearance of a compound odontoma presenting as a radiopaque mass in the right maxillary canine-premolar region (arrowheads).

Fig. 4 Gross appearance of the compound odontoma shown in Fig 2. Note the canine with attached follicle tissue (far right).

exostoses (1.1 %), epulides (1.1 %) and calcifying odontogenic cysts (1.1 %). The 102 cases of intraosseous odontomas were treated by surgical enucleation while the Fig. 3 A complex odontoma occurring as a well- two soft tissue odontomas were removed by simple circumscribed (arrowheads) mixed radioluscent/ excision. Examples of the gross appearances of radiopaque lesion between the right mandibular lateral incisor and canine. compound and complex odontomas are shown in Figs. 4 - 174

7. Histologic analysis showed that the compound and be that some of these cases were either submitted to other complex odontomas collectively accounted for about 78.8 pathology laboratories or were not sent for histopatholo- % of all odontomas studied (Table 1). A comparison of gic examination/confirmation. their demographic characteristics is detailed in Table 2. Previous studies have demonstrated that odontomas affect a wide age group with most cases being diagnosed Discussion in the second and third decades of life (2-8). A similar The 104 odontomas reviewed in this study accounted trend was observed in our study. However, the mean age for about 0.3 % of all specimens submitted in this (24.8 years) of our patients for all types of odontomas department (1967-1995). This figure is low compared to was about 7.2 - 10 years older than those of other studies the reported prevalence (range, 0.5 % - 1.0 %) from other (reported range of mean ages, 14.8 - 17.6 years) (2,8,15). biopsy service centers (4,8). Furthermore, contrary to Two earlier reports (6,15) have also shown that the mean previous findings (2,3,5,6) where odontomas reportedly age of patients with compound odontomas was about 5.5 represent the most common years younger than patients with complex odontomas. A diagnosed in the jaws, our records revealed that it ranked comparable observation was also made here, with the second to (a recent review study showed mean age difference being 4.4 years (Table 2). The that 401 cases of were diagnosed in this present study also confirmed previous findings that department between 1967 and 1991 (14)). It is possible odontomas in general do not exhibit any gender that the number of cases of odontomas diagnosed in this predilection (7,12). However, the observed gender department may not be reflective of its true prevalence in distribution pertaining separately to the compound and the general population. Probable reasons for this would complex odontomas in this series agrees in part with one study (7), but differs from some others (5,7,8). Only two previous studies had included a racial analysis of their odontoma cases. Kaugars et al. (6) found that a significant percentage of their cases occurred in blacks while Katz (5) observed that the proportion of Caucasian to black patients in his series mirrored the racial population composition of the sampled metropolitan area of Philadelphia. Our study also showed that the prevalence of odontomas among the various ethnic groups reflected the local racial population ratio. The maxillary/mandibular ratio of odontomas in our series (1: 1.04) compares favorably with some studies (range, 1: 1.1 - 1: 1.2) (7,16) but differs from others (1.03: 1 - 1.9: 1) (2,4,6,8,14). The percentage of anteriorly-located odontomas as observed here (38.5%) also falls within the reported range (36.7 % - 59.8%) (2,4,6,8,15). As with previous studies (5,8), we found that compound odontomas occurred more commonly in Fig. 5 Another example of compound odontoma, also the maxilla. However, unlike these studies (5,8), complex associated with a partially formed canine. odontomas in Malaysians showed a preference for the

Fig. 6 The gross appearance of a complex odontoma Fig. 7 A complex odontoma associated with a supernumerary presenting as a well-circumscribed mass with a nodular tooth (S). surface (arrows). 175 mandible. The reported tendency (8) for these Odontogenic tumors. Analysis of 706 cases. J. Oral histological types to exhibit a distinct predilection for the Surg., 36, 771-778 anterior and posterior jaw segments, respectively, was 4. Toretti, E.F., Miller; A.R. and Peezick, B. (1984) likewise noted in this study. The 2 extraosseous Odontomas. An analysis of 167 cases. J. Pedod., 8, odontomas in the current series occurred in the anterior 282-284 maxilla. While the clinical signs and symptoms of an 5. Katz, R.W. (1989) An analysis of compound and odontoma are generally considered nonspecific, their complex odontomas. J. Dent. Child., 56, 445-449 radiologic appearances are often fairly distinctive and 6. Kaugars, G.E., Miller, M.E. and Abbey, L.M. (1989) characteristic such that these lesions are often accurately Odontomas. Oral Surg. Oral Med. Oral Pathol., 67, diagnosed pre-operatively. A similar observation was 172-176 also made here. However, the number of odontomas 7. Or, S. and Yucetas, S.(1987) Compound and complex radiographically observed in a -like odontomas. Int. J. Oral Maxillofac. Surg., 16, 596-599 relationship in this study was small (4.2 %) compared 8. O'Grady, J.F., Radden, B.G. and Reade, P.C. (1987) with an earlier report (27.6 %) (6). Odontomas occurring Odontomas in an Australian population. Aust. Dent. in association with calcifying odontogenic cysts are well J., 32,196-199 recognized. In this series, a substantial number of these 9. Siar, C.H., Ng, K.H., Devadas, V. and Murugasu, P. cases (8.7 %) were noted. This is considerably higher (1987) Peripheral odontogenic fibroma with an than that of Kaugars' study (0.9 %) (9). In another study extraosseous odontoma. Report of a case. J. Oral (16) of 30 central non-neoplastic calcifying odontogenic Med., 42, 115-116 cysts, 10 (33.3 %) showed simultaneous occurrence of 10. To, E.W.H (1989) Compound composite odontoma odontomas. Odontomas are benign, hamartomatous associated with an impacted canine. Case report. Aust. odontogenic lesions and the treatment of choice is Dent. J., 34, 414-416 conservative surgical enucleation (7,13,17,18). For soft 11. Motokawa, W., Braham, R.L. and Taniguichi, K. tissue odontomas, simple excision is an adequate (1990) Idiopathic odontoma formation following treatment (12). All the cases in this series were treated in avulsion of immature permanent incisors. Two case this same manner. While recurrences are decidedly rare reports. J. Dent. Child., 57, 303-305 in odontomas, the lack of follow-up records in most of 12. Guinta, J.L. and Kaplan, M.A. (1990) Peripheral, soft these cases prevented evaluation in this aspect. In tissue odontomas. Two case reports. Oral Surg. Oral summary, this review shows that odontomas are not, by Med. Oral Pathol., 69, 406-411 comparison, commonly diagnosed lesions in Malaysia 13. Takeda, Y. (1991) Duct-like structures in odontogenic and their demographic as well as clinicopathologic epithelium of compound odontoma. J. Oral Pathol. features were generally in close accord with similar series Med., 20, 184-186 obtained from other geographic areas. 14. Siar, C.H. and Ng, K.H. (1993) Ameloblastoma in Malaysia. A 25 year review. Ann. Acad. Med. Acknowledgments Singapore, 22, 856-860 The authors are grateful to the staff of the Division of 15. Slootweg, P.J. (1981) An analysis of the Stomatology for their secretarial and technical assistance; interrelationship of the mixed odontogenic tumors; to all the dental specialists for their case contributions , ameloblastic fibro-odontomes that made this study possible; and to Dr. Mak Joon Wah, and the odontomes. Oral Surg. Oral Med. Oral Director, Institute for Medical Research, for his Pathol., 51, 266-273 permission to publish this paper. 16. Ng, K.H. and Siar, C.H. (1995) Morphometric analysis of epithelial components and dentinoid References formation in non-neoplastic calcifying odontogenic 1. Kramer, I.R.H., Pindborg, J.J. and Shear, M. (1992) cyst. J. Nihon Univ. Sch. Dent., 37, 156-162 Histological typing of odontogenic tumors. 2nd ed., 17. Bodin, I., Julin, P. and Thomson, M.(1983) 21, Springer-Verlag, Berlin Odontomas and their pathological sequels, Dento- 2. Budnick, S.D. (1976) Compound and complex maxillo-fac. Radiol., 12, 109-114 odontomas. Oral Surg. Oral Med. Oral Pathol., 42, 18. Acton, C.H.C. and Savage, N.W. (1987) Odontomas 501-506 and their behaviour. A review. Aust. Dent. J., 32, 3. Regezi, J.A., Kerr, D.A. and Courtney, R.M. (1978) 430-435