Odontoma has been classified in to several types since it was first reported by Oudet in 1821. The recent trend has been to classify odontoma into two types, i.e., complex and compound odontoma, or three, i.e., complex, compound and odonto-ameloblastoma. Recently we experienced a case of odontoma, which originated at the left mandibular molar site of a 56-year-old woman. The tumor was extirpated in one piece under general anesthesia and diagnosed as a complex odntoma histopathologically. Utilizing the past reports (during the period from January 1970 to February 1983) in Japan, we statistically studied the frequency of odontoma with regard to classification, sex, location, age and size.
