Which mandibular jaw movement produced by the temporomandibular joint is described as occurring when the condyle rotates anteriorly and posteriorly over the surface of the disc itself, which remains static, allowing the mandible to move up and down?

• A. Translational movement
• B. Protrusive movement
• C. Rotational movement
• D. Retrusive movement

Answer: (C)

Rotational movement is the hinge-like action of the jaw. In this phase, the condyle pivots on its axis across the surface of the articular disc while the disc stays relatively in place, so the mandible can move up and down without sliding forward. This contrasts with translational movement, where the condyle and disc glide forward together along the articular eminence to allow greater opening. Protrusive and retrusive refer to forward or backward movements of the lower jaw, not the hinge action described.