A very radiopaque lesion is found on the facial bone of the anterior mandible in a clinical photo and periapical radiograph. Among the differential diagnoses, which is the ONLY radiopaque option?

Correct answer: C. Exostosis (bony protuberance)

• A. A mucocele is a soft tissue lesion — not radiopaque.
• B. Periapical granuloma is radiolucent — not radiopaque.
• C. Correct. An exostosis is a benign bony outgrowth (like a torus) that appears radiopaque on radiograph because it is composed of dense cortical bone. When presented with a photo of a bony bump and asked which differential is radiopaque, exostosis is the answer.
• D. A radicular cyst is radiolucent — not radiopaque.