210 Theories and techniques of oral implantology

condition poses no problem for the implantologist.

Ameloblastoma. An ameloblastoma, also called an adamantinoma, epithelial odontoma, or multilocular cyst, is a benign odontogenic tumor of epithelial origin arising from either the dental lamina or its derivatives. It grows slowly but is the most aggressive of the odontogenic tumors. If not re-moved, it becomes extremely deforming and crippling. Unlike most benign tumors, it is not encapsulated.

An ameloblastoma may occur any time between the twentieth to the fiftieth year, though usually in the late thirties. The mandible is far more commonly affected than the maxilla, with most of the lesions

located in the molar area. Almost 30% arise from preexisting follicular cysts.

Among the first clinical signs, which may take years to develop, are tooth displacement in the involved area and consequent malocclusion. The jaw enlarges, but the tumor rarely breaks through the cortical bone. Radiographically the lesion may appear unicystic or multicystic, the latter having a soap bubble appearance (Fig. 6-15). In addition to the clearly defined main mass, small radiographically undetectable segments separated from it have usually invaded bone marrow well away from the mass. For this reason an ameloblastoma should be boldly approached surgically, removing apparently normal

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Fig. 6-15. A, An ameloblastoma is a highly aggressive tumor that causes enlargement of the jaw and shifting of the teeth. B, An ameloblastoma with a blunt root resorption. C, A multilocular ameloblastoma appears as soap bubble—like radiolucencies. (From Kolas, S., and others: Radiographic patterns of resorption seen in some gnathodental hard-tissue disturbances, Dent. Clin. N. Amer., November, 1968.)