An X-ray shows a compound odontoma-like radiopaque lesion. What is the fibroma-looking lesion on the interdental papilla that would NOT be in its differential diagnosis?

Correct answer: A. Adenoid odontogenic tumor (AOT) — NOT in the DDx of an interdental fibroma-like lesion

• A. Correct. A fibroma-like lesion on the interdental papilla has a DDx of reactive lesions: peripheral ossifying fibroma, pyogenic granuloma, and peripheral giant cell granuloma. The ADENOID ODONTOGENIC TUMOR (AOT) is NOT in this differential — AOT is a central (intraosseous) lesion of the anterior maxilla in young females, not an interdental papilla lesion.
• B. Peripheral ossifying fibroma (POF) is a common reactive lesion of the interdental papilla — it IS in the DDx.
• C. Peripheral giant cell granuloma occurs in the interdental papilla/gingiva — it IS in the DDx.
• D. Pyogenic granuloma (lobular capillary hemangioma) commonly affects the interdental papilla — it IS in the DDx.