A radiograph of the anterior mandible shows well-defined circular radiopacities superimposed over the roots. Clinically there are bony nodules on the lingual aspect. What are these?

Correct answer: C. Exostoses (lingual tori)

• A. Idiopathic osteosclerosis (dense bone island) is usually a solitary, irregular, non-expansile opacity most often in the mandibular premolar-molar region, without a palpable correlate.
• B. Sialoliths in this region would be soft-tissue opacities in the submandibular duct, best seen on an occlusal film, and would come with a history of mealtime swelling.
• C. CORRECT. Mandibular tori and exostoses project as sharply circumscribed, homogeneous, circular RADIOPACITIES superimposed on the roots because the beam passes through a dense lingual bony mass. Correlating the film with palpable bony nodules confirms it. They are developmental, benign, and require no treatment unless they interfere with a prosthesis or become ulcerated.
• D. Condensing osteitis is a diffuse periapical sclerosis attached to the apex of a tooth with a large restoration or pulpal inflammation — it is not a discrete circular opacity over the mid-root.

Note: Whenever a radiopacity does not fit any dental structure, palpate. Tori, exostoses and the mylohyoid ridge all cast confusing opacities. The clinical exam settles what the film cannot.