Ameloblastomas: a clinicopathological study of 66 cases from IREPO-CHILE

Introduction: Ameloblastomas are benign odontogenic tumors locally invasive recently reclassified into four groups by the World Health Organization (WHO) in the year 2005.
Objetive: To determine the relative frequency of ameloblastomas according to the new WHO Classification of Odontogenic Tumours (2005) and to compare their clinical and histopathologic features.
Methods: The clinico-pathological features of 66 selected ameloblastoma cases from the Instituto de Referencia de Patología Oral (IREPO) of the School Dentistry of the University of Chile, were studied. The age of the two most frequent types were compared by the t student test.
Results: The most frequent ameloblastoma was the Solid Ameloblastoma type (SA) with 30 cases and a mean age of 39 years, 28 cases were Unicystic Ameloblastoma type (UA) with a mean age of 31 years, 3 cases were Peripheral Ameloblastoma (PA) with a mean age of 73 years and one case of Desmoplastic Ameloblastoma type was 33 years old at the time of diagnosis. In four cases the specific type of ameloblastoma was not determined. No statistic differences were observed  between the groups in study (p<0,005). The male:female ratio was 1:1,1.  Fifty-nine (89%) of the 66 ameloblastomas were located in the mandible, constituted 87% for SA, and 100% for UA.
Conclusions: In this group of patients, the most frequent ameloblastoma was the Solid type, followed by the Unicystic type.  No differences were observed in relation to age and location between SA and UA.