Dermoid cysts within the maxillofacial skeleton are extremely rare, with only 13 cases in the literature. The present report describes a new long-standing intraosseous DC and reviews the literature.

A 69-year-old female presented with an expansile mandibular lesion, presenting a large radiolucency with the second and third molars impacted and displaced to the inferior mandibular border. Microscopic examination showed an intraosseous DC, lined by stratified keratinizing epithelium, with multiple aggregates of sebaceous cells and well formed sebaceous glands. Impaction of both second and third molars is an indication of initial development before the physiologic eruption time at approximately age 12. Thus, this presents an extremely longstanding intraosseous DC of at least 45 years duration. Analysis of the literature indicates that in comparison with the more common odontogenic keratocyst, intraosseous DC seems to have a very slow growth rate, and an indolent behavior.