The oral and maxillofacial area is a complex region with many tissues and structures and is thus the site of much diverse pathology. Embryo -logically, they are for the major part derived from migrating cells of the cranial neural crest (ectomesenchyme) and not merely from mesoderm, and that they contain teeth. The latter, especially, results in the presence of lesions that are not found in other bones, i.e, odontogenic cysts and tumors. Other lesions, not strictly odontogenic but also mainly confined to the jaw bones, are giant cell lesions, fibro-osseous lesions, and the melanotic...