Odontoma: a clinicopathologic study of 81 cases

Odontoma is the most common odontogenic tumor. It includes 2 types, the compound and complex odontomas. There has not been a series study of the clinical and histologic features of odontomas from Taiwan. This study evaluated the clinicopathologic features of odontoma in Taiwanese.

Cases of odontoma treated from 1998 to 2002 identified from medical records were included. The microscopic features, radiographic features, and clinical history of the patients were reviewed and analyzed.

A total of 81 odontomas in 81 patients (36 males and 45 females) were included. There were 62 compound and 19 complex odontomas. The mean age of the patients was 18 years with the majority of odontomas occurring in the first (32%) and second decade (38%) of life. Odontomas had a marked predilection for the maxilla (70%) and for the anterior region of the jaw (83%), particularly for the anterior maxilla (62%). Sixty four (79%) of the 81 odontomas were associated with 80 impacted teeth, including 71 permanent teeth, 2 deciduous teeth, and 7 supernumerary teeth. Of the 71 impacted permanent teeth, the maxillary central incisor (27%) was most commonly affected, followed by the maxillary canine (26%) and mandibular canine (24%). Histologic examination revealed enamel matrix in 90%, dentin in 100%, cementum in 88%, pulp tissue in 96%, fibrous capsule in 93%, ghost cells in 83%, reduced enamel epithelium in 86%, and nests of odontogenic epithelium in 58% of odontomas. Dentigerous cyst was associated with 9% of odontomas.

In this series, odontomas occurred most often in the first and second decade of life. Although complex odontomas are usually found in the posterior jaw, in this Taiwanese series they were most commonly found in the anterior maxilla. Odontoma is frequently associated with an impacted tooth and occasionally with a dentigerous cyst. No recurrence of odontomas was found after surgical excision with follow-up of 1 to 15 years.