The unicystic ameloblastoma deserves separate consideration on the basis of its clinical, radiologic, and pathologic features and its response to treatment. It refers to those cystic lesions that show clinical, radiographic, or gross features of a jaw cyst, but on histologic examination show a typical ameloblastomatous epithelium lining part of the cyst cavity. The lesion is most commonly found on the mandible posterior area, and often asymptomatic, although large lesions may cause a painless swelling of the jaws. The lesion typically appears as a circumscribed radiolucency that surrounds the crown of an unerupted molar. These are usually considered to be a dentigerous, residual cyst on the relationship of the lesion to teeth in the area. Three histopathologic variants of unicystic ameloblastoma may be seen. 1) Luminal type, 2) Intraluminal type, 3) Mural type. In this case, these tumor was treated as cysts by enucleation with iliac bone graft, and the diagnosis of ameloblastoma is made after microscopic examination of the presumed cyst.