Focal osseous dysplasia.

Focal osseous dysplasia (FOD) is one of the benign fibro-osseous lesions of the jaw bones and the most commonly occuring benign fibro-osseous lesion. This entity occurs more commonly in females and has a predilection for African Americans. Radiographically, the lesion has a variable appearance depending on the duration but may appear as a radiolucent to radiopaque lesion that can be well to poorly defined. Hisotologically, when biopsied, there are fragments of bony trabeculae intermixed with fibrous stroma with incomplete stromal vasculature. The main differential diagnosis is with ossifying fibroma, which is neoplastic while FOD is considered a reactive process. Most patients with FOD may be followed clinically without surgical intervention.