Temporomandibular Joint Disorder (TMD) or TMJ Dysfunction describes a complex group of muscular and articular disorders affecting the TMJ, leading to pain, dysfunction and eventually degeneration.
What causes it?
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.
Is it common?
Estimates for the incidence of TMD vary between 4-25%. Up to 3% of Americans seek treatment for TMD each year. At presentation, most patients are 20-50 years old and prevalence is 2-3 times higher in females.
What are the symptoms?
Typical symptoms include: jaw clicking or crepitus, restricted opening, transient locking and pain. Symptoms may be exacerbated by mastication. TMD pain is generally described as an “ache” located immediately anterior to the ear canal, causing ear pain, but may refer to other areas of the face, head, neck and shoulders. TMD patients often suffer concurrently from headaches and/or neck pain, suggesting a common link arising from the upper cervical spine. Clinicians should be particularly vigilant for cardiac origins of jaw pain, particularly in higher risk populations.
In some cases, TMD cannot be assessed by clinical evaluation alone. Panoramic x-rays are of limited help in identifying articular causes of TMD. CT is the imaging of choice (over 4 times better than plain films) for identifying TMJ osteoarthritis. The reliability of MRI is excellent for detecting disc displacements and effusion. The differential diagnosis of TMD would include: disc displacement, degeneration, fracture, infection (i.e. parotid gland, tooth), dental pathology, neoplasm, trigeminal neuralgia, and cardiogenic referral.
How can chiropractic help? Do I need surgery?
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.
We believe in a holistic approach combining manual therapy, exercises, and lifestyle modification as well as co-management with dentistry. Give us a call to see how we can help (434)293-3800