Which finding is most consistent with degenerative OA of the TMJ?

• A. Absence of joint noises
• B. Pure muscle tenderness without joint signs
• C. Crepitus indicating cartilage wear and degenerative changes
• D. Healthy joint with no symptoms

Answer: (C)

Degenerative OA of the TMJ is defined by wear of the articular cartilage and rough joint surfaces. As the jaw moves, the roughened surfaces rub together, producing crepitus—grinding or crackling sounds that can be heard or felt. This noise is a direct sign of degenerative changes in the joint and is more characteristic of OA than purely muscular pain or a completely silent, healthy joint. Absence of joint noises would suggest no joint involvement, and pure muscle tenderness without any joint signs points to a myofascial pain pattern rather than OA. A healthy joint with no symptoms does not fit OA either. Hence, crepitus indicating cartilage wear and degenerative changes best fits TMJ OA.