Temporomandibular disorders (TMD) are a collection of disorders characterized by facial pain and/or problems involving the jaw. Most cases of temporomandibular disorders are caused by problems in the facial and head muscles, problems involving the soft tissues of the jaw joint (TMJ or temporomandibular joint), or problems involving the hard structures of the jaw. Commonly, people who complain of TMD have both a muscular problem and a problem in the joint.

The pain reported by TMD patients is typically located in the facial/jaw muscles, in front of the ear, or in the jaw joint. TMD patients may also report headache, other facial pains, earache, dizziness, ringing in the ears, and neck/shoulder/upper and lower back pain. TMD patients may report a variety of jaw joint problems other than pain, including clicking, popping, or grating sounds in the joint or a sense that the jaw is "locked" in the open or closed position. Patients may report difficulty opening their jaws wide as well as a sense that their bite (occlusion) feels "off".

The signs and symptoms of TMD are widespread, and most individuals will experience at least one sign or symptom of TMD during their lives. However, only 5% of the population will experience pain severe enough to need professional assistance. TMD is also more common in younger adults (under age 45) than in older adults. Both men and women are equally likely to experience the signs and symptoms of TMD, but women seek care at least three times more frequently than men.

Both physical and psychological factors are involved in the development of TMD. some of the physical factors are: arthritis and other systemic medical conditions; trauma to the head or neck due to car accidents, work- or home-related accidents, or physical abuse; poor dental treatment (e.g., fillings that are too "high" or crowns and bridges that don't fit); prolonged mouth opening (occurring during a dental visit or general anesthesia). Physical factors that are not associated with TMD include prior orthodontic treatment or a poor "bite".

Some of the psychological and behavioral factors associated with TMD are: clenching or grinding of the teeth; chronic chewing of gum or pieces of ice, biting on fingernails, cheeks, lips, pencils, erasers, and caps of pens; stress; depression and anxiety; poor work habits or work environments (e.g., cradling a phone to the ear by "hunching" up a shoulder, awkward positioning of a computer keyboard or monitor).

Studies of TMD patients, particularly those whose pain is located in the muscles, show that TMD patients react to stress with increased facial/jaw muscle activity. TMD patients may also have higher levels of facial/jaw muscle activity while they are at rest than non-TMD individuals. Finally, TMD patients seem to be less aware and less able to control their facial/jaw muscles than non-TMD individuals.

Treatment for TMD can range from conservative, reversible treatments to highly complex, lengthy, expensive, and irreversible techniques. Some of the irreversible techniques include spot grinding of the teeth (known as equilibration), orthodontics, major reconstructive work (crowns and bridges), and various kinds of jaw surgery. These irreversible techniques do not provide better relief that the more conservative, reversible approaches, and some may actually make the pain problem worse.

There are two major conservative, reversible techniques for treating TMD. Studies have also shown that these techniques are highly effective in reducing the pain and discomfort associated with TMD. The large majority of patients who use one or more of these techniques can reasonably expect that their pain will be reduced by about 80%. These techniques are (1) splints (mouthguards), and (2) behavioral techniques.

Splints are made of hard acrylic. They fit over the upper or lower teeth. Splints work because they help put muscles at rest. There are many ways in which splints can be made, but the simplest varieties appear to be the most effective. However, many patients find that the splint reduces the clarity of their speech. The splint often has to be adjusted for comfort every few weeks, and-this requires return visits to the clinic or office. Finally, some people cannot adapt to the splint.

Several behavioral techniques are used in TMD. The most common are relaxation, biofeedback training, habit modification, and stress management. In relaxation training, patients learn how to relax themselves generally. Where there are specific sites of muscular tension, biofeedback can be used. The goal of both relaxation and biofeedback training are two-fold: (1) to teach patients how to detect or become aware of their muscle tension and their undesirable oral habits (such as clenching) and (2) to teach patients how to reduce the tension to more normal levels and begin to eliminate the oral habits.

Stress Management is used when everyday stresses also play a role in a patient's pain. In stress management, the goal is to identify stressors, develop and implement plans for managing the stressors, and evaluate the effectiveness of the plans in reducing stress and in reducing pain. For patients who are severely depressed or who have other psychological problems, psychotherapy is strongly recommended.

The behavioral techniques take from 6-12 sessions to learn, often in one-hour individual sessions, scheduled every week or two, with a therapist. Behavioral techniques work best with patients who believe that their active participation and involvement is critical to the success of treatment.

Studies show that splints and behavioral techniques provide the same relief from pain.Thus, patients need not worry which treatment is "best".

Finally, medications and physical therapy are often used as an adjunct to treatment. Over-thecounter medications such as aspirin or Tylenol or prescription pain-relievers can be helpful. However, tranquilizers such as Valium do not appear to be especially useful in treating TMD. Sophisticated practitioners may also suggest that TMD patients use a low dose of an anti-depressant as a pain reliever. Medications and physical therapy are useful, but they provide only symptomatic relief. Also, many people are sensitive to drugs and cannot take them or choose not to use them.

Bruxism:

Bruxism is the non-functional and forceful clenching or grinding of teeth. It is considered an important factor in many disorders of the teeth, gums, jaw joint (TMJ), and muscles of the face, head and neck. While splints help even out the forces in the jaw, they do not reduce the bruxing behavior. For this reason, behavioral techniques are frequently prescribed and are thought to be important by most dentists. It is thought that stress related to worrying or "run on" thought processes are the most important "emotional" causes of bruxism.

Biofeedback from the jaw muscles themselves is also used to help patients learn to be aware of facial muscle tension and thereby lower it. Typically sensors are attached over the jaw muscles (masseter) and a visual or auditory signal is made available to the patient. By getting this subtle feedback, most patients can gradually lower their muscle tension.

Chronic Muscle Pain:

Many of the patients who have been diagnosed as having TMJ or TMD really are suffering from chronic muscle pain. This can come from the muscles that support the jaw, from forehead muscles, from neck muscles or from other facial muscles. It is generally agreed that stress plays a role in these syndromes and thus biofeedback is often recommended. Following the fitting of a intraoral splint by a qualified dentist, the biofeedback usually consists of two stages. First the patient is taught relaxation techniques often accompanied by stress management counseling, as mentioned above, followed by specific muscle feedback. This may include very specific muscles and/or broad groups of muscles as is appropriate. Some recent studies have shown that the biofeedback and stress management combination with a splint produce long lasting (6 month) success in the reduction of pain. Since other treatment approaches have either been shown to be ineffective or have not been tested, this biofeedback approach appears to be the best currently available treatment protocol. It is common for the biofeedback protocol to require 8-12 weekly sessions with an appropriately trained practitioner. More sessions are required if the person has a head injury in addition to the chronic pain problem.

To summarize: Temporomandibular disorders refer to both painful muscles and to problems in the soft tissue or hard structures of the jaw joint. In many cases this disorder can be accompanied by bruxism and chronic pain. They are relatively common, but only a small percentage of symptomatic individuals seek treatment. Both dental/medical and psychological /behavioral factors can influence TMD, and prospective patients should be fully and carefully assessed. Prospective patients should seek conservative, reversible care before accepting a recommendation for irreversible--and often costly--treatment. Studies show that conservative techniques such as splints and various behavioral procedures--relaxation training, biofeedback training, habit modification, stress management--are effective in reducing pain.

Crockett, D.J., Foreman, M.E., Alden, L., & Blasberg, B. (1986). A comparison of treatment modes in the management of Myofacial Pain Dysfunction Syndrome. Biofeedback and SelfRegulation, 11(4), 279-291.

Dahlstrom, J., Carlsson, S.G., Gale, E.N., & Jansson, T.G. (1984). Clinical and electromyographic effects of biofeedback training in mandibular dysfunction. Biofeedback and Self-Regulation, 9(1), 37-47.Dalen, K., Ellersten, B., Espelid, I., & Gronningsater, A.G. (1986). EMG feedback in the treatment of myofacial pain dysfunction syndrome. Acta Odontol Scand, 44, 279-284.

Flor, H. and Birbaumer, N. Comparisons of electromyographic biofeedback, cognitive-behavioral therapy, and conservative medical interventions in the treatment of chronic musculoskeletal pain. Journal of Consulting and Clinical Psychology, 1993, 61:653-58

Turk, D., Hussein, Z. and Rudy, T. Effects of intraoral appliance and biofeedback/stress management alone and in combination in treating temporomandibular disorders. Journal of Prosthetic Dentistry.1993, 70:158-64.

© 1995
Association for Applied Psychophysiology and Biofeedback