Occlusal therapy in the management of chronic orofacial pain.

Review of the literature indicates that most routine orofacial dysfunctions are characterized by deep pain. Various disorders of the masticatory systems, particularly musculoskeletal conditions, are thought to be triggered by occlusal disharmonies. The pain component develops following a pattern of bruxism, muscle hyperactivity, fatigue and spasm. Treatment for most disorders has been to modify the occlusion, although the rational for doing so appears questionable.CRITICAL ISSUES IN THE FIELD OF OCCLUSION RELATED TO OROFACIAL PAIN ARE REVIEWED: occlusal disharmonies, coincidence of retruded-intercuspal contact positions, non-working side interferences, maximum intercuspation of teeth, occlusal adjustment, and occlusal appliances.The studies reviewed fail to support the clinical objective of obtaining equal contact at retruded and intercuspal positions and that the lateral pterygoid muscles stabilize the temporomandibular joint. The relationship between non-working side interferences and pain dysfunction is also not readily supported by controlled studies. Occlusal adjustment appears to be unsatisfactory as a modality for management of pain: not all patients improved following treatment, some relapse occurs even with the most stable contacts, and other treatments such as intra-articular injections of corticosteroids reduced symptoms more readily. Occlusal splints seem to reduce most clinical signs and symptoms on both a short-term and long-term basis. Placement of mandibular orthopedic repositioning appliances results in reduction of pain in some patients, but usually this treatment is followed by extensive rehabilitation.Six major areas are suggested for clinical studies that attempt to relate occlusion to management of orofacial pain. These include: establishment of an ideal jaw position, sequencing of symptoms in the pain history, relationship of pain to other symptoms, development of physiological methods to assess how occlusal modification affects pain perception and pain tolerance, and determination of which treatment modalities produce the most effective relief of pain.