Reducing chronic masseter and temporalis muscular hyperactivity with computer-guided occlusal adjustments

Muscle hyperactivity is a potential source of symptomatology in patients with temporomandibular disorders. Various occlusal adjustment procedures have been advocated to reduce hyperactivity. A new, measurement-driven, occlusal adjustment procedure, known as immediate complete anterior guidance development (ICAGD), has been shown through nonsimultaneous electromyography to lessen masticatory muscle hyperactivity effectively by reducing posterior disclusion time to <0.4 sec in all mandibular excursions. This reduction, in turn, lessens the volume of periodontal ligament compressions that create additive and excessive functional muscle contractions via a feedback mechanism involving the trigeminal nerve. This case report describes the treatment of chronic muscular hyperactivity with a computer-guided ICAGD enameloplasty and simultaneously recorded electromyography. Follow-up visits showed that after reduction, the pretreatment levels of excursive muscular hyperactivity were lessened and lasting. This result is caused by the shorten ed posterior disclusio time resulting in an equally reduced time to muscle shutdown.