The term "ameloblastoma" as applied to this particular tumor was suggested by Churchill in 1943 to replace the term adamantinoma, coined by Malassez in 1885, since the latter term implies the formation of hard tissue, and no such material is present in this lesion. The ameloblastoma is a true neoplasm of odontogenic epithelial origin. It is the second most common odontogenic neoplasm, and only odontoma outnumbers it in reported frequency of occurrence. Excluding odontoma, the incidence of ameloblastoma, is at least equal to the incidence of all the other odontogenic neoplasms combined.