Which sign best indicates TMJ involvement rather than purely muscular origin?

• A. Joint noises
• B. Tenderness in masseter
• C. Localized cheek pain
• D. No swelling

Answer: (A)

Joint noises during jaw movement signal intra-articular TMJ dysfunction. The joint contains the disc and articular surfaces, and when they don’t move smoothly—such as with disc derangement or degenerative changes—clicking, popping, or crepitus arises as the components engage abnormally with opening and closing. These noises originate from the joint itself, not from the surrounding muscles, so they point to TMJ involvement rather than a purely muscular issue.

Tenderness in the masseter points to muscle origin or myofascial pain; it can occur with TMD but does not confirm joint pathology. Localized cheek pain could come from dental, sinus, or soft-tissue sources and isn’t specific to the TMJ. Absence of swelling doesn’t differentiate joint from muscular causes and isn’t diagnostic on its own.