Temporomandibular joint syndrome

Definition

Temporomandibular joint syndrome (TMJ) is the name given to a group of symptoms that cause pain in the head, face, and jaw. The symptoms include headaches, soreness in the chewing muscles, and clicking or stiffness of the joints.

Description

TMJ syndrome, which is also sometimes called TMJ disorder, results from pressure on the facial nerves due to muscle tension or abnormalities of the bones in the area of the hinge joint between the lower jaw and the temporal bone. This hinge joint is called the temporomandibular joint. There are two temporomandibular joints, one on each side of the skull just in front of the ear. The temporal bone is the name of the section of the skull bones where the jawbone (the mandible) is connected. The jawbone is held in place by a combination of ligaments, tendons, and muscles. The temporomandibular joint also contains a piece of cartilage called a disc, which keeps the temporal bone and the jawbone from rubbing against each other. The jaw pivots at the joint area in front of the ear. The pivoting motion of the jaw is complicated because it can move downward and from side to side as well as forward. Anything that causes a change in shape or functioning of the temporomandibular joint will cause pain and other symptoms.

Causes & symptoms

TMJ syndrome has several possible physical causes:

• Muscle tension. Muscle tightness in the temporomandibular joint usually results from overuse of muscles. This overuse in turn is often associated with psychological stress and clenching or grinding of the teeth (bruxism ).
• Injury. A direct blow to the jaw or the side of the head can result in bone fracture, soft tissue bruising, or a dislocation of the temporomandibular joint itself.
• Arthritis. Both osteoarthritis and rheumatoid arthritis can cause TMJ.
• Internal derangement. Internal derangement is a condition in which the cartilage disk lies in front of its proper position. In most cases of internal derangement, the disc moves in and out of its correct location, making a clicking or popping noise as it moves. In a few cases, the disc is permanently out of position, and the patient's range of motion in the jaw is limited.
• Hypermobility. Hypermobility is a condition in which the ligaments that hold the jaw in place are too loose and the jaw tends to slip out of its socket.
• Birth abnormalities. These are the least frequent causes of TMJ but do occur in a minority of patients. In some cases, the top of the jawbone is too small; in others, the top of the jawbone outgrows the lower part.
• Oral habits. Some dentists think that such habits as wide yawning, lip or tongue biting, or mouth breathing can contribute to TMJ by putting the jaw in an abnorml position for long periods of time.
• Dental work. Some people develop TMJ following dental work that requires the dentist to hold the patient's jaw open wide for extended periods of time. Other patients develop TMJ following removal of the wisdom teeth.

In addition to the physical causes of TMJ, dentists are increasingly recognizing the importance of psychosocial factors in the disorder. One recent finding is the importance of the patient's concept of pain itself. People who are already suffering from depression or an anxiety disorder, people who have little social support in their lives, and people who feel that they have little control over their lives are at greater risk of developing chronic pain syndromes, including TMJ.

In many cases TMJ results from a combination of psychological, anatomical, and functional factors rather than a single abnormality.

The symptoms of TMJ depend in part on its cause or causes. The most common symptoms are facial pain in front of the ears; headaches; sore jaw muscles; a clicking sound when chewing; a grating sensation when opening and closing the mouth; and temporary locking of the jaw. Some patients also report a sensation of buzzing or ringing in the ears. Usually, the temporomandibular joint itself is not painful. Most cases of TMJ are seen in women between 20–50 years of age.

Diagnosis

TMJ syndrome is most frequently diagnosed by dentists. The dentist can often diagnose TMJ based on physical examination of the patient's face and jaw. The examination might include pressing on (palpating) the jaw muscles for soreness or asking the patient to open and close the jaw in order to check for misalignment of the teeth in the upper and lower jaw. This condition is called malocclusion. The dentist might also gently move the patient's jaw in order to check for loose ligaments.

Imaging studies are not usually necessary to diagnose TMJ. In most cases, x rays and MRI scans of the temporomandibular joint will be normal. Consequently, these two tests are not commonly used to diagnose TMJ. If the dentist suspects that the patient has internal derangement of the disc, a technique called arthrography can be used to make the diagnosis. In an arthrogram, a special dye is injected into the joint, which is then xrayed. Arthrography can be used to evaluate the movement of the jaw and the disc as well as size and shape, and to evaluate the effectiveness of treatment for TMJ.

Another aid to diagnosing TMJ is a new questionnaire designed to discriminate between facial pain related to TMJ and myogenic facial pain, a chronic condition that is caused by trigger points in the muscles of the face and neck. The McGill Pain Questionnaire has been reported to have a high degree of reliability in distinguishing between patients with TMJ and patients with myogenic facial pain.

Treatment

In many cases, the cause of pain in the TMJ area is temporary and disappears without treatment. About 80% of patients with TMJ will improve in six months without medications or physical treatments.

Biofeedback , which teaches an individual to control muscle tension and any associated pain through thought and visualization techniques, is also a treatment option for TMJ. In biofeedback treatments, sensors placed on the surface of the jaw are connected to a special machine that allows the patient and healthcare professional to monitor a visual and/or audible readout of the level of tension in the jaw muscles. Through relaxation and visualization exercises, the patient learns to relieve the tension and can actually see or hear the results of his or her efforts instantly through the sensor readout on the biofeedback equipment. Once the technique is learned and the patient is able to recognize and differentiate between the feelings of muscle tension and muscle relaxation,

the electromyographic biofeedback equipment itself is no longer needed and the patient has a powerful, portable, and self-administered treatment tool to deal with pain and tension.

Stress management and relaxation techniques may be useful in breaking the habit of jaw clenching and teeth grinding. Tight jaw muscles are often relaxed by applying warm compresses to the sides of the face. Acupuncture may relieve the jaw tension associated with TMJ. Massage therapy and deep tissue realignment can also assist in releasing the clenching pattern. Extra calcium and magnesium can also help relax jaw muscles.

Allopathic treatment

Allopathic practitioners are increasingly recommending more conservative treatments for TMJ, on the grounds that the majority of patients can be successfully treated with noninvasive, reversible approaches. These include patient education and eating softer foods as well as medication and the use of bite plates.

Patients with TMJ can be given muscle relaxants if their symptoms are related to muscle tension. Some patients may be given aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) for minor discomfort. If the TMJ is related to rheumatoid arthritis, it may be treated with corticosteroids, methotrexate (MTX, Rheumatrex) or gold sodium (Myochrysine).

Patients who have difficulty with bruxism may be treated with splints. A plastic splint called a nightguard is given to the patient to place over the teeth before going to bed. Splints can also be used to treat some cases of internal derangement by holding the jaw forward and keeping the disc in place until the ligaments tighten. The splint is adjusted over a period of two to four months.

TMJ can also also be treated with ultrasound, stretching exercises, transcutaneous electrical nerve stimulation (TENS), stress management techniques, or friction massage. A 2002 study done at the University of Maryland found that all of these treatments are helpful to patients with TMJ, but none appears to be clearly superior to the others.

Surgery is ordinarily used only to treat TMJ caused by birth deformities or certain forms of internal derangement caused by misshapen discs.

Expected results

The prognosis for recovery from TMJ is excellent for almost all patients. Most patients do not need any form of long-term treatment. Surgical procedures to treat TMJ are quite successful. In the case of patients with TMJ caused by arthritis or infectious diseases, the progression of the arthritis or the success of eliminating infectious agents determines whether TMJ can be eliminated.

Resources

BOOKS

"Disorders of the Temporomandibular Joint." In Merck Manual of Medical Information: Home Edition, edited by Robert Berkow, et al. Whitehouse Station, NJ: Merck Research Laboratories, 1997.

Murphy, William A., Jr., and Phoebe A. Kaplan. "Temporomandibular Joint." In Diagnosis of Bone and Joint Disorders, edited by Donald Resnick. Philadelphia: W. B. Saunders Company, 1995.

PERIODICALS

Grace, E. G., E. Sarlani, and B. Read. "The Use of an Oral Exercise Device in the Treatment of Muscular TMD." Cranio Clinics International 20 (July 2002): 204-208.

Mongini, F., F. Raviola, and M. Italiano. "The McGill Pain Questionnaire in Patients with Myogenic Facial Pain and TMJ Disorders." Journal of Oral Rehabilitation 29 (September 2002): 875.

Nilges, P. "Psychosocial Factors in Patients with Temporomandibular Pain." [in German] Schmerz 16 (September 2002): 365-372.

Syrop, S. B. "Initial Management of Temporomandibular Disorders." Dentistry Today 21 (August 2002): 52-57.

Vanderas, A. P., and L. Papagiannoulis. "Multifactorial Analysis of the Aetiology of Craniomandibular Dysfunction in Children." International Journal of Paediatric Dentistry 12 (September 2002): 336-346.

Yamakawa, M., T. Ansai, S. Kasai, et al. "Dentition Status and Temporomandibular Joint Disorders in Patients with Rheumatoid Arthritis." Cranio Clinics International 20 (July 2002): 165-171.

ORGANIZATIONS

American Dental Association. 211 East Chicago Avenue, Chicago, IL 60611. (312)440–2500. <www.ada.org>.

National Institute of Dental and Craniofacial Research (NIDCR). National Institutes of Health, Bethesda, MD 20892. (301) 496-4261. <www.nidr.nih.gov>.

TMJ Association, Ltd. <www.tmj.org>.

Paula Ford-Martin

Rebecca J. Frey, PhD

Temporomandibular joint disorders

Definition

Temporomandibular joint (TMJ) disorder, also known as TMD, is the name given to a group of symptoms that cause pain in the facial muscles and dysfunction in the head, face, and jaw. TMD often has psychological as well as physical causes.

Description

TMD results from pressure on the facial nerves due to muscle tension, injury, or bone abnormalities. Some 70% of adults exhibit at least one sign of TMD, but only 5% seek treatment. Most sufferers are women between ages 20 and 50.

The TMJ connects the temporal bone with the condyle of the mandible anterior to the ear on each side of the skull . The jaw pivots on ligaments, tendons, and muscles to allow motion downward and laterally as well as forward. Anything that causes a change in shape or functioning of the TMJ can cause pain and other symptoms.

Causes and symptoms

Causes

TMD has varied causes:

• Bruxism , or unconscious clenching or grinding of the teeth, is the most common cause of TMD. Bruxism occurs during periods of stress or during sleep. It results in muscle tension and soreness around the jaw joint and in the facial muscles.
• Misalignment of the teeth or displacement of the TMJ disc may contribute to TMD.
• Injury to the jaw or side of the head, either from a direct blow or from repeated and prolonged opening and closing (as in gum chewing), can result in a dislocation of the TMJ and subsequent TMD problems.
• Arthritis in different forms can lead to TMD. Traumatic arthritis from an injury, osteoarthritis , and rheumatoid arthritis are all possible causes.
• Hypermobility, a condition in which the ligaments of the TMJ are too loose, may allow the mandible to slip out of position and create TMD.
• Poor posture is another potential cause of TMD. When an individual carries his or her head too far forward and strains the neck muscles, TMD can result. In one research study in Texas, patients who were given posture training along with traditional treatment had greater improvement than those without posture training.
• Birth abnormalities are the least frequent cause of TMD, but can occur. In some cases, the condyle of the mandible is too large or too small.

KEY TERMS

Arthrography —A testing technique in which a special dye is injected into the joint, which is then x rayed.

Bruxism —Habitual clenching and grinding of the teeth, especially during sleep.

Condyle —An articular prominence of a bone.

Electromyographic biofeedback —A method for relieving jaw tightness by monitoring the patient's attempts to relax the muscle while the patient watches a gauge. The patient gradually learns to control the degree of muscle relaxation.

Fibromyalgia —A complex, chronic condition which causes widespread pain and fatigue, as well as a variety of other symptoms.

Malocclusion —The misalignment of opposing teeth in the upper and lower jaws.

Mandible —The lower jaw.

Orofacial —Pertaining to the mouth and face.

Osteoarthritis —A type of arthritis marked by chronic degeneration of the cartilage of the joints, leading to pain and sometimes loss of function.

Rheumatoid arthritis —A chronic autoimmune disorder marked by inflammation and deformity of the affected joints.

Temporal bones —The compound bones that form the right and left sides of the skull above the ears.

Tinnitus —A sensation of ringing or roaring in the ears that can only be heard by the individual affected.

Transcutaneous electrical nerve stimulation —A method for relieving the muscle pain of TMD by stimulating nerve endings that do not transmit pain. It is thought that this stimulation blocks impulses from nerve endings that do transmit pain.

Symptoms

The symptoms of TMD depend in part on its cause. They include orofacial pain, restricted jaw function, and clicking or stiffness in the joints. Patients may also suffer from headaches, ear, neck, and shoulder pain, or tinnitus. Classic symptoms are pain in front of the ear that spreads to the ear, mandible, cheek, and temple. Pain may be worse in the morning, and may be cyclical. Patients may also report noise in the joint during chewing, and limited mouth opening.

Diagnosis

Physical examination and patient history

TMD is most frequently diagnosed in the dental office based on physical examination . As the patient opens, closes, and moves the jaw laterally, palpation (physical examination by feeling with the hands) can detect joint popping and clicking, or a stethoscope may be placed in front of the ear to listen to the jaw movements. Jaw and facial muscles are checked for tenderness, and the patient's bite is checked for misalignment.

A careful patient history looks for such clues as recent injury or recent dental work. The patient should be asked about the duration and severity of jaw and face pain. Any history of insomnia, stress, anxiety , depression, chronic pain, or fibromyalgia should be documented.

Imaging studies

Imaging studies are not usually necessary to diagnose TMD. In most cases, x rays and magnetic resonance imaging (MRI) scans of the temporomandibular joint are normal. If the dentist suspects the patient has malpositioning of the TMJ disc, he or she can use arthrography to make the diagnosis. Arthrography can be used to evaluate the movement of the jaw and disc as well as their size and shape, and to evaluate the effectiveness of treatment.

Treatment

In 80% of TMD sufferers, symptoms improve in six months without treatment. When treatment is necessary, various modalities are used.

Phase I treatment

Phase I treatment is conservative and non-invasive, with no irreversible changes. Its purpose is to eliminate muscle spasms, swelling, and pain. Initially, a dentist may prescribe moist heat, aspirin, or a nonsteroidal anti-inflammatory drug, with a soft diet to alleviate symptoms.

Patients who have difficulty with bruxism are usually treated with splints. A plastic splint called a nightguard or mouthguard is constructed and worn at night. The splint can break the cycle of bruxing and allow sore muscles to relax. Splints can also be used to treat malpositioning by holding the mandible forward and keeping the disc in place until the ligaments tighten. The splint is adjusted over a period of two to four months.

Muscle relaxants can be prescribed if symptoms are related to muscle tension or fibromyalgia. If the TMD is related to rheumatoid arthritis, it may be treated withcorticosteroids , methotrexate (MTX, Rheumatrex), or gold sodium (Myochrysine).

TMD can also be treated with ultrasound, electromyographic biofeedback, stretching exercises, transcutaneous electrical nerve stimulation, stress management techniques, friction massage, or posture training.

A patient who is suffering emotional or psychological problems that contribute to his or her TMD must address those problems before expecting relief of TMD symptoms.

Phase II treatment

By definition of the American Dental Association, Phase II treatment is non-reversible, invasive therapy. Its purpose is to definitively correct any discrepancies in the TMJ. Modalities include adjustment of the occlusion, orthodontics, reconstruction of the teeth, surgery, or a combination of these treatments.

In the 1980s, synthetic implants were used to replace the TMJ disc, but the implants proved to be too fragile to withstand jaw pressure. By 1999, all implants were taken off the market by the FDA. A new implant design was approved by the FDA in 2000.

Any patient considering Phase II treatment should be advised to get a second and possibly third opinion, and to proceed cautiously.

Prognosis

The prognosis for recovery from TMD is excellent for almost all patients. Most do not need any form of long-term treatment. In the case of patients with TMD associated with arthritis or fibromyalgia, the progression of the condition determines whether TMD can be eliminated.

Health care team roles

Every member of the dental team should be alert for TMD symptoms in patients, though only the dentist can prescribe treatment. A dental hygienist or assistant can use a skull or charts to help the patient understand the function and action of the TMJ. Additionally, dental auxiliaries can educate the patient about correct posture and modifying behavior such as gum chewing and fingernail biting.

If the dentist determines a splint is necessary, the hygienist or assistant can take impressions of the teeth and prepare plaster casts from the impressions. A dental laboratory technician then constructs the splint, and the dentist places it, checking to ensure an exact fit.

Prevention

To prevent TMD from developing, suggestions to patients can include:

• Avoid overuse of the jaw. Gum chewing is the major culprit, along with fingernail biting.
• Try not to grind the teeth. Follow the "lips together, teeth apart" rule. Upper and lower teeth should meet only for chewing. Make a conscious effort to keep the masseter (cheek) muscles relaxed.
• Sleep on the back. Sleeping on either side can put pressure on the TMJ.
• Manage stress. Relaxation exercises and biofeedback can help.
• Use correct posture. Carrying the head in a forward position has been shown to affect TMD. Also, correct bad ergonomic habits such as holding a telephone receiver between the ear and shoulder.

Resources

BOOKS

"Disorders of the Temporomandibular Joint." In Merck Manual of Medical Information: Home Edition, edited by Robert Berkow, et al. Whitehouse Station, NJ: Merck Research Laboratories, 1997.

PERIODICALS

Guthrie, Catherine. "Peace for Troubled Jaws?" Health (March 2001): 90-94.

"Temporomandibular Joint (TMJ) Syndrome." Clinical Reference Systems (Annual 2000): 1565.

Walling, Anne D. "Review of Diagnosis and Treatment of TMJ Disorders." American Family Physician (November1998): 1841-2.

Wright, Edward F., Manuel A. Domenech, and Joseph R. Fischer, Jr. "Usefulness of Posture Training for Patients with Temporomandibular Disorders." Journal of the American Dental Association (February 2000): 202-11.

ORGANIZATIONS

American Academy of Head, Neck and Facial Pain. 520 West Pipeline Road, Hurst, TX 76053.

American Dental Association. 211 E. Chicago Ave., Chicago, IL 60611. (312) 440-2500. <http://www.ada.org>.

OTHER

"An Overview of the Fundamental Features of Fibromyalgia Syndrome." The National Fibromyalgia Partnership Inc. Web site <http://www.fmpartnership.org/FMPartnership.htm> (1999 edition).

"Treatment of TMJ." The American Academy of Head, Neck and Facial Pain website. <http://www.drshankland.com/treatment.html> (April 3, 2001).

Cathy Hester Seckman, R.D.H.

Temporomandibular Joint Disorders

Definition

Temporomandibular joint (TMJ) disorder, also known as TMD, is the name given to a group of symptoms that cause pain in the facial muscles and dysfunction in the head, face, and jaw. TMD often has psychological as well as physical causes.

Description

TMD results from pressure on the facial nerves due to muscle tension, injury, or bone abnormalities. Some 70% of adults exhibit at least one sign of TMD, but only 5% seek treatment. Most sufferers are women between ages 20 and 50.

The TMJ connects the temporal bone with the condyle of the mandible anterior to the ear on each side of the skull. The jaw pivots on ligaments, tendons, and muscles to allow motion downward and laterally as well as forward. Anything that causes a change in shape or functioning of the TMJ can cause pain and other symptoms.

Causes and symptoms

Causes

TMD has varied causes:

• Bruxism, or unconscious clenching or grinding of the teeth, is the most common cause of TMD. Bruxism occurs during periods of stress or during sleep. It results in muscle tension and soreness around the jaw joint and in the facial muscles.
• Misalignment of the teeth or displacement of the TMJ disc may contribute to TMD.
• Injury to the jaw or side of the head, either from a direct blow or from repeated and prolonged opening and closing (as in gum chewing) can result in a dislocation of the TMJ and subsequent TMD problems.
• Arthritis in different forms can lead to TMD. Traumatic arthritis from an injury, osteoarthritis, and rheumatoid arthritis are all possible causes.
• Hypermobility, a condition in which the ligaments of the TMJ are too loose, may allow the mandible to slip out of position and create TMD.
• Poor posture is another potential cause of TMD. When an individual carries his or her head too far forward and strains the neck muscles, TMD can result. In one research study in Texas, patients who were given posture training along with traditional treatment had greater improvement than those without posture training.
• Birth abnormalities are the least frequent cause of TMD, but can occur. In some cases, the condyle of the mandible is too large or too small.

Symptoms

The symptoms of TMD depend in part on its cause. They include orofacial pain, restricted jaw function, and clicking or stiffness in the joints. Patients may also suffer from headaches, ear, neck, and shoulder pain, or tinnitus. A classic symptom is pain in front of the ear that spreads to the ear, mandible, cheek, and temple. Pain may be worse in the morning, and may be cyclical. Patients may also report noise in the joint during chewing, and limited mouth opening.

Diagnosis

Physical examination and patient history

TMD is most frequently diagnosed in the dental office based on physical examination. As the patient opens, closes, and moves the jaw laterally, palpation (physical examination by feeling with the hands) can detect joint popping and clicking, or a stethoscope may be placed in front of the ear to listen to the jaw movements. Jaw and facial muscles are checked for tenderness, and the patient's bite is checked for misalignment.

A careful patient history looks for such clues as recent injury or recent dental work. The patient should be asked about the duration and severity of jaw and face pain. Any history of insomnia, stress, anxiety, depression, chronic pain, or fibromyalgia should be documented.

Imaging studies

Imaging studies are not usually necessary to diagnose TMD. In most cases, x rays and magnetic resonance imaging (MRI) scans of the temporomandibular joint are normal. If the dentist suspects the patient has malpositioning of the TMJ disc, he or she can use arthrography to make the diagnosis. Arthrography can be used to evaluate the movement of the jaw and disc as well as their size and shape, and to evaluate the effectiveness of treatment.

Treatment

In 80% of TMD sufferers, symptoms improve in six months without treatment. When treatment is necessary, various modalities are used.

Phase I treatment

Phase I treatment is conservative and noninvasive, with no irreversible changes. Its purpose is to eliminate muscle spasms, swelling, and pain. Initially, a dentist may prescribe moist heat, aspirin, or a nonsteroidal anti-inflammatory drug, with a soft diet to alleviate symptoms.

Patients who have difficulty with bruxism are usually treated with splints. A plastic splint called a nightguard or mouthguard is constructed and worn at night. The splint can break the cycle of bruxing and allow sore muscles to relax. Splints can also be used to treat malpositioning by holding the mandible forward and keeping the disc in place until the ligaments tighten. The splint is adjusted over a period of two to four months.

Muscle relaxants can be prescribed if symptoms are related to muscle tension or fibromyalgia. If the TMD is related to rheumatoid arthritis, it may be treated with corticosteroids, methotrexate (MTX, Rheumatrex), or gold sodium (Myochrysine).

TMD can also be treated with ultrasound, electromyographic biofeedback, stretching exercises, transcutaneous electrical nerve stimulation, stress management techniques, friction massage, or posture training.

A patient who is suffering emotional or psychological problems that contribute to his or her TMD must address those problems before expecting relief of TMD symptoms.

Phase II treatment

By definition of the American Dental Association, Phase II treatment is non-reversible, invasive therapy. Its purpose is to definitively correct any discrepancies in the TMJ. Modalities include adjustment of the occlusion, orthodontics, reconstruction of the teeth, surgery, or a combination of these treatments.

In the 1980s, synthetic implants were used to replace the TMJ disc, but the implants proved to be too fragile to withstand jaw pressure. By 1999, all implants were taken off the market by the FDA. A new implant design was approved by the FDA in 2000.

Any patient considering Phase II treatment should be advised to get a second and possibly third opinion, and to proceed cautiously.

Prognosis

The prognosis for recovery from TMD is excellent for almost all patients. Most do not need any form of long-term treatment. In the case of patients with TMD associated with arthritis or fibromyalgia, the progression of the condition determines whether TMD can be eliminated.

Health care team roles

Every member of the dental team should be alert for TMD symptoms in patients, though only the dentist can prescribe treatment. A dental hygienist or assistant can use a skull or charts to help the patient understand the function and action of the TMJ. Additionally, dental auxiliaries can educate the patient about correct posture and modifying behavior such as gum chewing and fingernail biting.

If the dentist determines a splint is necessary, the hygienist or assistant can take impressions of the teeth and prepare plaster casts from the impressions. A dental laboratory technician then constructs the splint, and the dentist places it, checking to ensure an exact fit.

Prevention

To prevent TMD from developing, suggestions to patients can include:

• Avoid overuse of the jaw. Gum chewing is the major culprit, along with fingernail biting.
• Try not to grind the teeth. Follow the "lips together, teeth apart" rule. Upper and lower teeth should meet only for chewing. Make a conscious effort to keep the masseter (cheek) muscles relaxed.
• Sleep on the back. Sleeping on either side can put pressure on the TMJ.
• Manage stress. Relaxation exercises and biofeedback can help.
• Use correct posture. Carrying the head in a forward position has been shown to affect TMD. Also, correct bad ergonomic habits such as holding a telephone receiver between the ear and shoulder.

KEY TERMS

Arthrography— A testing technique in which a special dye is injected into the joint, which is then x rayed.

Bruxism— Habitual clenching and grinding of the teeth, especially during sleep.

Condyle— An articular prominence of a bone.

Electromyographic biofeedback— A method for relieving jaw tightness by monitoring the patient's attempts to relax the muscle while the patient watches a gauge. The patient gradually learns to control the degree of muscle relaxation.

Fibromyalgia— A complex, chronic condition which causes widespread pain and fatigue, as well as a variety of other symptoms.

Malocclusion— The misalignment of opposing teeth in the upper and lower jaws.

Mandible— The lower jaw.

Orofacial— Pertaining to the mouth and face.

Osteoarthritis— A type of arthritis marked by chronic degeneration of the cartilage of the joints, leading to pain and sometimes loss of function.

Rheumatoid arthritis— A chronic autoimmune disorder marked by inflammation and deformity of the affected joints.

Temporal bones— The compound bones that form the right and left sides of the skull above the ears.

Tinnitus— A sensation of ringing or roaring in the ears that can only be heard by the individual affected.

Transcutaneous electrical nerve stimulation— A method for relieving the muscle pain of TMD by stimulating nerve endings that do not transmit pain. It is thought that this stimulation blocks impulses from nerve endings that do transmit pain.

Resources

BOOKS

"Disorders of the Temporomandibular Joint." In Merck Manual of Medical Information: Home Edition, edited by Robert Berkow, et al. Whitehouse Station, NJ: Merck Research Laboratories, 1997.

PERIODICALS

Guthrie, Catherine. "Peace for Troubled Jaws?" Health (March 2001): 90-94.

"Temporomandibular Joint (TMJ) Syndrome." Clinical Reference Systems (Annual 2000): 1565.

Walling, Anne D. "Review of Diagnosis and Treatment of TMJ Disorders." American Family Physician (November 1998): 1841-2.

Wright, Edward F., Manuel A. Domenech, and Joseph R. Fischer, Jr. "Usefulness of Posture Training for Patients with Temporomandibular Disorders." Journal of the American Dental Association (February 2000): 202-11.

ORGANIZATIONS

American Academy of Head, Neck and Facial Pain. 520 West Pipeline Road, Hurst, TX 76053.

American Dental Association. 211 E. Chicago Ave., Chicago, IL 60611. (312) 440-2500. 〈http://www.ada.org〉.

OTHER

"An Overview of the Fundamental Features of Fibromyalgia Syndrome." The National Fibromyalgia Partnership Inc. website〈http://www.fmpartnership.org/FMPartnership.htm〉 (1999 edition).

"Treatment of TMJ." The American Academy of Head, Neck and Facial Pain Website. 〈http://www.drshankland.com/treatment.html〉 (April 3, 2001).

Temporomandibular Joint Disorders

Definition

Temporomandibular joint disorder (TMJ) is the name given to a group of symptoms that cause pain in the head, face, and jaw. The symptoms include headaches, soreness in the chewing muscles, and clicking or stiffness of the joints. They often have psychological as well as physical causes.

Description

TMJ disorder, which is also sometimes called TMJ syndrome, results from pressure on the facial nerves due to muscle tension or abnormalities of the bones in the area of the hinge joint between the lower jaw and the temporal bone. This hinge joint is called the temporomandibular joint. There are two temporomandibular joints, one on each side of the skull just in front of the ear. The name of the joint comes from the two bones that make it up. The temporal bone is the name of the section of the skull bones where the jaw bone (the mandible) is connected. The jaw bone is held in place by a combination of ligaments, tendons, and muscles. The temporomandibular joint also contains a piece of cartilage called a disc, which keeps the temporal bone and the jaw bone from rubbing against each other. The jaw pivots at the joint area in front of the ear. The pivoting motion of the jaw is complicated because it can move downward and from side to side as well as forward. Anything that causes a change in shape or functioning of the temporomandibular joint will cause pain and other symptoms.

Causes and symptoms

Causes

TMJ syndrome has several possible physical causes:

• Muscle tension. Muscle tightness in the temporomandibular joint usually results from overuse of muscles. This overuse in turn is often associated with psychological stress and clenching or grinding of the teeth (bruxism ).
• Injury. A direct blow to the jaw or the side of the head can result in bone fracture, soft tissue bruising, or a dislocation of the temporomandibular joint itself.
• Arthritis. Both osteoarthritis and rheumatoid arthritis can cause TMJ.
• Internal derangement. Internal derangement is a condition in which the cartilage disk lies in front of its proper position. In most cases of internal derangement, the disc moves in and out of its correct location, making a clicking or popping noise as it moves. In a few cases, the disc is permanently out of position, and the patient's range of motion in the jaw is limited.
• Hypermobility. Hypermobility is a condition in which the ligaments that hold the jaw in place are too loose and the jaw tends to slip out of its socket.
• Birth abnormalities. These are the least frequent cause of TMJ but do occur in a minority of patients. In some cases, the top of the jawbone is too small; in others, the top of the jawbone outgrows the lower part.

Symptoms

The symptoms of TMJ depend in part on its cause. The most common symptoms are facial pain in front of the ears; headaches; sore jaw muscles; a clicking sound when chewing; a grating sensation when opening and closing the mouth; and temporary locking of the jaw. Some patients also report a sensation of buzzing or ringing in the ears. Usually, the temporomandibular joint itself is not painful. Most cases of TMJ are seen in women between 20-50 years of age.

Diagnosis

Dental examination and patient history

TMJ disorders are most frequently diagnosed by dentists. The dentist can often diagnose TMJ based on physical examination of the patient's face and jaw. The examination might include pressing on (palpating) the jaw muscles for soreness or asking the patient to open and close the jaw in order to check for misalignment of the teeth in the upper and lower jaw. This condition is called malocclusion. The dentist might also gently move the patient's jaw in order to check for loose ligaments.

Imaging studies

Imaging studies are not usually necessary to diagnose TMJ. In most cases, x rays and MRI scans of the temporomandibular joint will be normal. Consequently, these two tests are not commonly used to diagnose TMJ. If the dentist suspects that the patient has internal derangement of the disc, he or she can use a technique called arthrography to make the diagnosis. In an arthrogram, a special dye is injected into the joint, which is then x-rayed. Arthrography can be used to evaluate the movement of the jaw and the disc as well as size and shape, and to evaluate the effectiveness of treatment for TMJ.

Treatment

In many cases, the cause of pain in the TMJ area is temporary and disappears without treatment. About 80% of patients with TMJ will improve in six months without medications or physical treatments.

Medications

Patients with TMJ can be given muscle relaxants if their symptoms are related to muscle tension. Some patients may be given aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) for minor discomfort. If the TMJ is related to rheumatoid arthritis, it may be treated with corticosteroids, methotrexate (MTX, Rheumatrex) or gold sodium (Myochrysine).

Physical therapy and mechanical devices

Patients who have difficulty with bruxism are usually treated with splints. A plastic splint called a nightguard is given to the patient to place over the teeth before going to bed. Splints can also be used to treat some cases of internal derangement by holding the jaw forward and keeping the disc in place until the ligaments tighten. The splint is adjusted over a period of two to four months.

TMJ can also be treated with ultrasound, electromyographic biofeedback, stretching exercises, transcutaneous electrical nerve stimulation, stress management techniques, or friction massage.

Surgery

Surgery is ordinarily used only to treat TMJ caused by birth deformities or certain forms of internal derangement caused by misshapen discs.

Prognosis

The prognosis for recovery from TMJ is excellent for almost all patients. Most patients do not need any form of long-term treatment. Surgical procedures to treat TMJ are quite successful. In the case of patients with TMJ caused by arthritis or infectious diseases, the progression of the arthritis or the success of eliminating infectious agents determines whether TMJ can be eliminated.

Resources

BOOKS

Berktow, Robert, et al., editor. "Disorders of the Temporomandibular Joint." In Merck Manual of Medical Information: Home Edition. Whitehouse Station, NJ: Merck Research Laboratories, 1997.

KEY TERMS

Arthrography— An imaging technique that is sometimes used to evaluate TMJ associated with internal derangement.

Bruxism— Habitual clenching and grinding of the teeth, especially during sleep.

Electromyographic biofeedback— A method for relieving jaw tightness by monitoring the patient's attempts to relax the muscle while the patient watches a gauge. The patient gradually learns to control the degree of muscle relaxation.

Internal derangement— A condition in which the cartilage disc in the temporomandibular joint lies in front of its proper position.

Malocclusion— The misalignment of opposing teeth in the upper and lower jaws.

Mandible— The medical name for the lower jaw.

Osteoarthritis— A type of arthritis marked by chronic degeneration of the cartilage of the joints, leading to pain and sometimes loss of function.

Rheumatoid arthritis— A chronic autoimmune disorder marked by inflammation and deformity of the affected joints.

Temporal bones— The compound bones that form the left and right sides of the skull.

Transcutaneous electrical nerve stimulation— A method for relieving the muscle pain of TMJ by stimulating nerve endings that do not transmit pain. It is thought that this stimulation blocks impulses from nerve endings that do transmit pain.

TEMPOROMANDIBULAR JOINT DISORDERS

DEFINITION

Temporomandibular joint disorder (TMJ) is a group of symptoms that involve pain in the head, face, and jaw. Symptoms of TMJ include headaches, soreness in the chewing muscles, and clicking or stiffness of the joints. The disorder can be caused by psychological as well as physical factors. TMJ is also known as temporomandibular joint syndrome.

DESCRIPTION

The temporomandibular joint (pronounced TEM-pu-roh-man-DIBB-yuh-lur) connects the jawbone (the mandible) with the lower part of the skull (the temporal bone). The joint is located in front of the ear. It allows the jaw to move up and down, back and forth, and forward and backward. Various factors can alter the shape or motion of the temporomandibular joint, which may then put pressure on facial nerves. This pressure can result in pain in various parts of the head. Most cases of TMJ occur in women between the age of twenty and fifty.

Temporomandibular Joint Disorders: Words to Know

Arthrography:

An imaging technique in which a dye is injected into a joint to make X-ray pictures of the inside of the joint easier to study.

Internal derangement:

A condition in which the regular arrangement of parts in a system is disturbed. Some cases of TMJ are caused by a particular internal derangement in which the disc in the temporomandibular joint slips out of its normal position.

Mandible:

The scientific term for the lower jaw.

Temporal bones:

The bones that form the right and left sides of the skull.

CAUSES

TMJ syndrome has several possible physical causes:

• Muscle tension. Overuse of jaw muscles can cause tightness in the temporomandibular joint. A common cause of muscle tightness is stress. People who are overly worried may clench or grind their teeth excessively, which can cause muscle tension.
• Injury. A direct blow to the jaw or the side of the head can cause TMJ. The blow can break a bone, bruise soft tissue, or dislocate the temporomandibular joint itself.
• Arthritis (see arthritis entry). Arthritis is a disease of joints caused by a number of factors. Arthritis in the region of the temporomandibular joint can cause TMJ.
• Internal derangement. The temporomandibular joint contains a small piece of cartilage called a disc, which keeps the jawbone and the temporal bone from rubbing against each other. Sometimes the disc slips out of place creating what is known as an internal derangement. Often this condition can be detected by a clicking or popping sound caused by the disc moving in and out of its correct position. On rare occasions, the disc can become permanently displaced, and a patient may lose the ability to move his or her jaw in all normal ways.
• Hypermobility. Hypermobility is a condition in which ligaments in the temporomandibular joint become loose. Ligaments are pieces of tissue that hold bones together. In cases of hypermobility, the jaw may slip entirely out of its socket.
• Birth abnormalities. Children are sometimes born with defects in the temporomandibular joint. For example, the top of the jawbone may be too small. Such causes of TMJ are relatively rare.

SYMPTOMS

The symptoms of TMJ depend in part on its cause. The most common symptoms include the following:

• Facial pain in front of the ears
• Headaches
• Sore jaw muscles
• A clicking sound when chewing
• A grinding feeling when opening and closing the mouth
• Temporary locking of the jaw

Some patients also report a buzzing or ringing in the ears. In most cases, the temporomandibular joint itself is not painful.

DIAGNOSIS

TMJ is most commonly diagnosed by a dentist. The dentist can often tell simply by touching a patient's face if the temporomandibular joint is out of place. Manipulation of the jaw provides additional information. It may be possible to see that the patient's teeth do not close together properly. Looseness in the jaw may indicate hypermobility as well.

Imaging Studies

Imaging studies are used to obtain pictures of the interior of a person's body. X rays are probably the best-known form of imaging studies. In most cases, imaging studies are not very helpful in diagnosing TMJ because the temporomandibular joint will look normal in such studies. Arthrography (pronounced arr-THRAHG-ruh-fee) is one form of imaging that can be useful, however. In arthrography, a dye is injected into the patient's temporomandibular joint. The joint is then observed while being X-rayed. Any abnormal movement of the jaw can be observed by this method.

TREATMENT

The pain associated with TMJ usually goes away on its own without treatment. About 80 percent of patients with the disorder improve in six months without treatment.

Medications

The minor discomfort of TMJ can be treated with pain relievers such as aspirin or acetaminophen. Muscle relaxants may help if the condition is caused by muscle tension. Instances when TMJ is caused by arthritis can be treated with corticosteroids, methotrexate, gold sodium, or other anti-arthritic medications.

Physical Therapy and Mechanical Devices

Some patients experience serious problems with clenching and grinding of their teeth at night. For these patients a plastic splint called a nightguard can be prescribed. The nightguard is placed over the teeth before going to bed. Splints can also be used to hold the jaw and disc in place when these factors are responsible for the disorder.

TMJ can also be treated by a variety of other techniques, such as ultrasound, biofeedback, stretching exercises, electrical nerve stimulation, stress management techniques, or massage.

Surgery

Surgery can be used to place the temporomandibular joint back into its correct position. This approach is used almost exclusively in cases of TMJ caused by birth deformities or internal derangement.

PROGNOSIS

The prognosis for recovery from TMJ is excellent for almost all patients. Most patients do not need any form of long-term treatment. Surgical procedures used to treat TMJ are usually quite successful. The prognosis for cases of TMJ caused by arthritis depends on the progress of the arthritis itself.

PREVENTION

There is no way to prevent TMJ that is caused by physical factors. Stress-induced TMJ can be prevented by learning stress management techniques before the problem starts.

FOR MORE INFORMATION

Books

Shankland, Wesley E. TMJ: Its Many Faces, 2nd edition. Columbus, OH: Anadem, Inc., 1998.

Taddey, John J. TMJ: The Self Help Program. La Jolla, CA: Surrey Park Press, 1990.

Uppgaard, Robert O. Taking Control of TMJ: Your Total Wellness Program for Recovering from Tempromandibular Joint Pain, Whiplash, Fibromyalgia, and Related Disorders. Oakland, CA: New Harbinger Publications, 1999.