Small unilateral jaw gap variations: equilibrium changes, co-contractions and joint forces.

After complex prosthetic reconstructions, small differences in vertical distances between the left and right side of the jaw may occur during jaw closing, nevertheless providing bilateral tooth contacts in intercuspation by small deformations of the mandible. Their effects on the co-contraction of the masticatory muscles, the temporomandibular joint reaction forces, and the point of application of the resultant bite force vector in the maxillary occlusion plane - the so-called reduction point - have not been investigated, thus far simultaneously in one sample. The main goal of this study was to investigate variations of these measures in an experimental intercuspation simulated by one anterior and two posterior force transmission points.