Mapping mandibular rest in humans utilizing electromyographic patterns from masticatory muscles

As the mandible assumes its resting position in space, antagonistic muscles should assume their resting lengths as is demonstrated by resting and isometric electromyography. This zone of mandibular rest can be mapped using these physiologic parameters of muscle activity. Three positions were evaluated: a maximum physiologic open position, a maximum physiologic closed position, and a physiologic rest position. Additionally, each subject's maximum intercuspation position was evaluated. Within the physiologic zone of rest, formed by the maximum physiologic open position and maximum physiologic closed position, muscle recruitment was the greatest in a physiologic group. Results indicated that muscle function was significantly greater within the zone of mandibular rest than at the intercuspal position.