24-year-old male: 'a bump on my gums for the past year.' Clinical photo + radiograph. Most likely diagnosis?

Correct answer: C. Buccal exostosis

• A. Incorrect. A dense bony island is an intrabony radiopacity found incidentally on radiographs; it does not present as a visible/palpable gingival bump.
• B. Incorrect. An odontoma is an intraosseous lesion (often with an unerupted tooth); it is not typically a clinically visible long-standing gum 'bump.'
• C. Correct. A buccal exostosis is a benign, slow-growing nodular overgrowth of cortical bone presenting as a hard, asymptomatic 'bump' on the buccal alveolus — matching a stable lesion present for a year.
• D. Incorrect. PCOD occurs in the anterior mandible (often middle-aged Black women), is asymptomatic and intrabony, and does not present as a gingival bump in a 24-year-old male.