A patient has preauricular crepitus (crackling at the TMJ) but NO pain. Rheumatoid factor is NEGATIVE. What is the MOST likely diagnosis?

Correct answer: B. Osteoarthritis

• A. Incorrect. Rheumatoid arthritis is ruled out by the NEGATIVE rheumatoid factor (RF). Also, RA is a bilateral, systemic autoimmune disease — not typically presenting as isolated TMJ crepitus with negative RF.
• B. Correct. Painless preauricular crepitus with negative RF in a patient (especially middle-aged/older) is classic OSTEOARTHRITIS (OA) of the TMJ. OA involves progressive degradation of articular cartilage → bone-on-bone contact → crepitus. RF is negative in OA (unlike RA). The absence of pain at this stage is common in early-to-moderate TMJ OA.
• C. Incorrect. Gout arthritis affects the TMJ rarely and presents with acute pain, redness, and tophi — not painless crepitus.
• D. Incorrect. Psoriatic arthritis may affect the TMJ but is associated with a history of psoriasis and is less common than OA.