At what point is the TMJ capsule most taut?

The TMJ capsule is most taut at maximal opening. This is because, during maximal opening, the condyle of the mandible is positioned in a way that stretches the ligaments surrounding the TMJ. At this position, the intra-articular disc and ligaments are fully engaged, and the joints are at their maximum range of motion, which creates tension in the capsule to stabilize the joint. This tautness helps prevent excessive movement that could lead to dislocation or injury.

In contrast, at maximal closing, the jaw is fully closed, which would not impose the same level of tension on the capsule as the components of the joint are aligned and stabilized in a different way. Protrusion involves a forward movement of the mandible but does not necessitate the same degree of stretching in the capsule. Lastly, when resting with the teeth slightly apart, the capsule is in a neutral position, exhibiting less tautness as it is not under tension from the joint's movement.