Abstract
An analysis is presented of the force actions at the temporomandibular joint and in the muscles of mastication during biting. The resulting equations cannot be solved in order to determine the muscle and joint forces because the number of unknown quantities exceeds the number of equations. Solutions are obtained which minimize either the total force produced by the muscles of mastication or the force at the temporo-mandibular joint. It is shown that the predictions of muscle action obtained from these solutions are at variance with the muscles shown to be active experimentally. The limitations of the application of optimization procedures to redundant problems associated with muscle and joint force analyses are discussed.