Labial bone concavity.

Labial bone concavities are entities that can be mistaken radiographically for disease. Clinicians should be aware of them in order to make a proper diagnosis. In the area of the concavity, the bone is thinned and appears more radiolucent than the adjacent bone. Concavities are noted in the maxilla and in the mandible, usually in the anterior regions. In contrast to the Stafne defect, which is not easily amenable to palpation or visualization except by radiograph, labial concavities are palpable and are often visualized as an indentation in the area of the noted radiolucency. Radiographically, they may appear as defined radiolucencies, similar to a cyst, or with a ground-glass pattern, similar to a fibro-osseous disease. The reasons for their presence may vary from a congenitally missing tooth, a prominent canine fossa (due to anatomy or to a missing tooth), a malposed tooth, an anatomical variation, or a surgical defect. Once the diagnosis is made, no further treatment is recommended.