Central osteomas of the jaws have been infrequently reported, mostly presenting as a well-defined opacity on conventional radiography projections and as a hyperdensity on computed tomography scans. To increase the knowledge of the phenotypic expression of gnathic central osteomas, an unusual case has been described, including the clinical, radiographic, cone beam computed tomography (CBCT) and histopathologic findings. The lesion was initially discovered 4 years prior as an asymptomatic ovoid radiolucency in the posterior mandible.

A 25-year-old female presented with a hyperdense expansile mass with a hypodense rim on a CBCT scan. The enucleated mass was diagnosed as a compact central osteoma. A literature search has identified 4 other cases with similar hypodense borders on CT scans. We propose that a subset of central osteomas should be considered in the differential diagnosis of osteopathologies of the jaws with hyperdense internal architecture and hypodense borders, as seen on CT images.