Chvostek's sign is elicited by tapping which area, causing which reaction?

• A. The jaw; jerking
• B. The cheek; facial muscle spasm
• C. The temple; tremor
• D. The chin; grimace

Answer: (B)

Chvostek's sign reflects increased neuromuscular excitability, usually from hypocalcemia. It is elicited by tapping the facial nerve as it runs over the cheek, just in front of the ear and over the masseter. A positive sign is a brisk contraction or twitch of the ipsilateral facial muscles—often around the mouth or eye—when the cheek is tapped. This is why the best description is tapping the cheek to produce a facial muscle spasm. The sign helps indicate latent tetany due to low calcium. Regions like the temple or chin do not typically produce this same facial contraction, and the response is specifically a facial muscle spasm rather than a general tremor or grimace.