What occurs during the late phase of opening?

• A. Condylar rotation
• B. Lateral shift
• C. Posterior glide
• D. Anterior translation

Answer: (D)

Opening the jaw happens in two stages: at first the condyle rotates like a hinge within the lower part of the joint, and as opening continues, the condyle and its disc translate forward along the articular eminence. In the late phase, the main movement is anterior translation of the condyle (with the disc) under the eminence, which allows the mouth to open wider.

This translational glide is what distinguishes the late phase from the early, rotation-dominated phase. Posterior glide isn’t part of the opening movement, and a lateral shift would reflect deviation or asymmetry rather than a standard late-opening mechanism.