What sign is characteristic of disc displacement with reduction (DDwR)?

• A. A jaw joint click during movement that may disappear when the disc reduces
• B. A jaw joint click during movement that always remains
• C. Joint locking without any loud sound
• D. Pain that worsens with opening

Answer: (A)

The sign being tested is the jaw joint click that occurs with movement and may disappear when the disc reduces. In disc displacement with reduction, the articular disc sits anterior to the condyle when the mouth is closed. As you open, the disc slides back (reduces) onto the condyle, producing a characteristic click or pop. Because the disc reduces during opening, the sound can disappear once the reduction has occurred, which is a key feature distinguishing DDwR from other conditions. This differs from a situation where there is ongoing locking without a sound, or where pain is the only prominent feature, or where the click never resolves. The presence of a movement-related click that may stop after the disc reduces is the hallmark.