Biomechanics of the Mandible

The most frequently used biomechanical analogy for the mandible has been the Class III lever, in which the condyle acts as a fulcrum, the masticatory muscles as applied force, and the bite pressure as resistance. Various workers have suggested either directly or indirectly, that there is little or no reactive force at either mandibular condyle. Mandibular movement occurs as a complex series of interrelated three-dimensional rotational and translational activities. Mandibular movement is limited by the ligaments and the articular surfaces of the temporomandibular joints as well as by the morphology and alignment of the teeth. The collective activities of masticatory muscles in different configurations have enabled us to perform a variety of mandibular movements.

Keywords: Biomechanics, Class III lever, Lever action, Mandibular movement, Non-lever action.