What describes the rotation phase of closing arthrokinematics?

The rotation phase of closing arthrokinematics specifically involves the posterior rotation or spin of the condyle on the disc. During this phase, as the mouth closes, the condyle rotates backward. This motion occurs primarily within the glenoid fossa, where the condyle is articulating with the articular disc. This posterior rotation allows the condyle to move up and back, effectively contributing to the closure of the jaw.

Understanding this motion is critical because it emphasizes the role of the articulating surfaces in facilitating efficient jaw movement. The specifics of this movement provide insights into normal and pathological functions of the TMJ, such as when assessing for TMJ disorders or during clinical evaluations involving jaw mechanics.

Other movements like anteroinferior spin, vertical translation of the disc, and lateral movement of the mandible describe different aspects of TMJ function but are not specifically representative of the rotation phase during closing. Hence, the focus on the posterior spin of the condyle on the disc is paramount in accurately defining this arthrokinematic movement.