Which of the following is NOT typically classified as a common intra-articular TMJ pathology?

• A. Myofascial pain without intra-articular involvement
• B. Disc displacement (with or without reduction)
• C. Degenerative joint disease/osteoarthritis
• D. Osteoarthritis

Answer: (B)

Understanding what counts as intra-articular helps distinguish the sources of TMJ pain. Intra-articular TMJ pathology involves structures inside the joint capsule, such as the articular disc, the condylar head, and the synovial surfaces. Disc displacement with or without reduction is a classic intra-articular problem because the disc itself is within the joint and its abnormal position alters joint mechanics. Degenerative joint disease or osteoarthritis describes degenerative changes of the joint surfaces and cartilage, which are also contained within the joint, making them intra-articular. Osteoarthritis is simply another term for that same intra-articular degenerative process. Myofascial pain without intra-articular involvement, on the other hand, originates in the muscles and fascia around the jaw rather than inside the joint capsule, so it is considered extra-articular. Therefore, the statement describing myofascial pain without intra-articular involvement is not a typical intra-articular TMJ pathology.