Most causes of TMD can be divided into either muscular or articular (joint related). TMD of muscular origin is more common and may arise from muscular hypertonicity, trigger points, fascial restrictions and/or functional muscle imbalance of the muscles of chewing (mastication). One of the most commonly involved muscles is the masseter. Other recognized triggers for muscular TMD include bruxism, clenching, cervicocranial dysfunction, postural syndromes, especially a forward head posture, and trauma. TMD symptoms may occur in up to one-third of those patients involved in a whiplash injury.

Disk displacement and osteoarthritis are common causes for TMD of joint-related origin. Other causes of TMD of articular origin include loose bodies, inflammatory arthropathy, trauma, mandibular fracture, dislocation, malocclusion, infection, and neoplasm. In TMD of articular origin, muscular dysfunction is secondary.

Studies vary on the relationship of premolar extraction to the development of TMD, but recent evidence refutes that link. Psychosocial disturbances including stress and depression, are another widely recognized co-morbidity for TMD.

Manual therapy is an effective treatment for TMD.  In fact, non-surgical intervention for muscular TMD has been shown to be as effective as any surgical intervention. Management should be conservative and simple, focusing on three main points: manual therapies, exercise, and avoidance of aggravating activities.

Manual therapies are necessary to address lesions in the masticatory system, neck, and upper torso. Intraoral myofascial therapy has been shown to reduce pain and improve jaw opening. Post-isometric relaxation (PIR), STM, or myofascial release should be directed at the: lateral pterygoid, temporalis, and masseter. Other muscles that may need consideration include the: suboccipital, anterior and posterior digastrics, medial pterygoid, SCM and trapezius. Manipulation of the cerviocranial, cervical and thoracic spine may be necessary.

Exercises to improve posture and TMJ function have been shown to be beneficial. Stretching exercises should address tightness of the muscles in the anterior and posterior neck and upper back. The patient should also perform neck strengthening exercises. Additional postural corrections may be necessary. The Rocabado 6×6 exercise protocol is a popular program to restore function between the jaw, neck, and shoulders. In contrast to popular opinion, some experts suggest that management of malocclusion is not essential in the treatment of TMD. Initially, passive modalities including laser therapy, heat, ice, ultrasound or iontophoresis may be helpful.

Patients should avoid aggravating activities like chewing gum or eating “rubbery” foods. Limit unnecessary talking. Supplementation with bromelain or MSM may be beneficial. A custom-fitted mouth guard (occlusal orthotic) may help minimize grinding or clenching and promote relaxation of masticatory muscles. Patients with nighttime symptoms should avoid stressful activity before bedtime and be aware of their sleep position. NSAIDs may provide benefit. In some cases, stress management techniques, like biofeedback, can assist patients in learning how to relax the jaw muscles.