A patient reports diffuse pain in the maxillary posterior region. Which test BEST distinguishes pulpal pain of dental origin from pain referred from the maxillary sinus?

Correct answer: C. Cold (thermal) testing of the individual teeth

• A. Palpation of the vestibule detects periapical or periosteal involvement but does not separate sinus from pulpal origin.
• B. A panoramic radiograph gives a poor view of the maxillary sinus and cannot assess pulpal status. If sinus imaging is required, Waters view or CBCT is far superior.
• C. CORRECT. COLD TESTING is the discriminating test because it isolates a SINGLE tooth and interrogates PULPAL status directly. A tooth with irreversible pulpitis gives a sharp, LINGERING response localising the source; in sinusitis every tested tooth responds NORMALLY, because the pulps are healthy and the pain arises from the sinus mucosa.
• D. PERCUSSION is unhelpful here precisely because it is positive in BOTH conditions — sinusitis characteristically causes tenderness to percussion of SEVERAL adjacent maxillary posterior teeth simultaneously, which is why it misleads rather than discriminates.

Note: Clinical pointers to SINUS origin: several adjacent teeth tender together, pain worse on bending forward or on a jarring step, associated nasal congestion or recent upper respiratory infection, and — critically — all pulps test VITAL with normal responses. Endodontic treatment on a vital tooth in a patient with sinusitis is a well-recognised avoidable error.