A periapical radiograph (no third molar present) shows an arrow pointing to a radiopaque structure just distal to the maxillary second molar. What is this structure?

Correct answer: C. Coronoid process of the mandible

• A. The tuberosity is the bony bulge of the maxilla itself distal to the last molar — not a separate triangular opacity superimposed in the space.
• B. The zygomatic process appears as a U- or J-shaped opacity over the molar roots, not the discrete triangular shadow distal to the arch.
• C. Correct. With the mouth open for a maxillary periapical, the triangular coronoid process of the mandible swings forward and superimposes distal to the maxillary tuberosity — the classic 'coronoid process' artifact.
• D. The hamular notch is a soft-tissue/bony depression posterior to the tuberosity, not a triangular radiopacity.