What sign helps differentiate TMJ OA from inflammatory arthropathy in TMD?

• A. Swelling, warmth, and systemic signs are typical of inflammatory arthropathy.
• B. Degenerative radiographic changes with wear are typical of OA; inflammatory arthropathy shows swelling, warmth, and systemic signs.
• C. OA presents with fever and warmth.
• D. OA and inflammatory arthropathy are indistinguishable radiographically.

Answer: (B)

The key idea is that TMJ osteoarthritis (OA) is a degenerative process, while inflammatory arthropathies provoke active joint inflammation. OA produces degenerative radiographic changes that reflect wear and tear—things like joint space narrowing due to cartilage loss, osteophyte formation, and subchondral sclerosis. In contrast, inflammatory arthropathy tends to cause soft tissue swelling, warmth, and systemic signs such as fever or elevated inflammatory markers. So the sign that best differentiates them is the presence of degenerative radiographic wear changes consistent with OA; inflammation shows swelling, warmth, and systemic signs rather than wear-based imaging features.