Temporomandibular (Jaw) Joint Diseases and Disorders

Temporomandibular joint diseases and disorders, commonly called "TMJ", refer to a complex and poorly understood set of conditions that can cause pain in the area of the jaw joint and associated muscles and/or problems using the jaw. Both or just one of the temporomandibular joints may be affected. TMJ diseases and disorders can affect a person’s ability to speak, eat, chew, swallow, and

Image of the face showing the Temporomandibular joint. Source: The TMJ Association

Signs and Symptoms

Pain is the most common symptom. TMJ pain is often described as a dull aching pain in the jaw joint and nearby areas, including the ear, which comes and goes. Some people, however, report no pain, but still have problems using their jaws. Other symptoms can include:

• Being unable to open the mouth comfortably
• Clicking, popping or grating sounds in the jaw joint
• Locking of the jaw when attempting to open the mouth
• Headaches
• A bite that feels uncomfortable or “off”
• Neck, shoulder and back pain
• Swelling on the side of the face

Additional symptoms may include: ringing in the ears, ear pain, decreased hearing, dizziness and vision problems.

Keep in mind that occasional discomfort in the jaw joint or chewing muscles is common, and is not always a cause for concern. Many people with certain TMJ problems get better without treatment. Often the problem goes away on its own in several weeks to months. However, if the pain is severe and lasts more than a few weeks, see your healthcare provider.

Causes

Not all causes are known. Some possible causes or contributing factors are injuries to the jaw area, various forms of Arthritis, dental procedures, genetics, hormones, low-level infections, auto- immune diseases, stretching of the jaw as occurs with inserting a breathing tube before surgery, and clenching or grinding of the teeth.

Diagnosis

Diagnosing TMJ diseases and disorders can be difficult and confusing. For example, facial pain can be a symptom of many conditions, such as sinus or ear infections, decayed or abscessed teeth, various types of headache, and facial neuralgia (nerve-related facial pain). At present, there is no widely accepted, standard test to correctly identify all TMJ conditions. In most cases, however, a complete evaluation, including a detailed medical history, the patient’s description of symptoms, and physical examination of the head, neck, face and jaw provide information useful for making a diagnosis.

Exams and tests

Imaging studies of the jaw may also be used as a diagnostic tool. These include:

• Routine Dental X-rays and Jaw Joint X-rays (Panoramic or Transcranial Radiographs) show the bony structure of the joint.
• Computed Tomography (CT or CAT Scan) provides greater detail of bone, but a somewhat limited view of the disc and soft tissues.
• Magnetic Resonance Imaging (MRI) provides images of the disc as well as the muscles and other soft tissues surrounding the joint.
• Tomography is a type of x-ray that shows cross sectional slices of the jaw area.

Tests that are recommended are often intended to rule out other possible medical conditions. A diagnosis of TMJ diseases and disorders may be made only after every other possibility has been considered and eliminated. Many TMJ patients see multiple healthcare providers, such as primary care physicians, dentists, sleep specialists, ear, nose and throat specialists, neurologists, endocrinologists, rheumatologists, pain specialists, chiropractors, etc., in their search for answers.

Treatment

Because most common jaw joint and muscle problems are temporary, lasting only weeks or months, simple care is all that is usually needed to relieve the discomfort. Self-care practices, for example, eating soft foods, applying ice or moist heat, and avoiding extreme jaw movements (such as wide yawning, loud singing, and gum chewing) are useful in easing symptoms.

Reversible Treatments

According to the National Institute of Dental and Craniofacial Research (NIDCR) of the National Institutes of Health (NIH), TMJ treatments should be reversible whenever possible. That means that the treatment should not cause permanent changes to the jaw or teeth.

Examples of reversible treatments are:

• Over-the-counter pain medications, used according to manufacturers’ instructions.
• Prescription medications prescribed by a healthcare provider.
• Gentle jaw stretching and relaxation exercises you can do at home. Your healthcare provider can recommend exercises for your particular condition, if appropriate.
• A Stabilization splint (biteplate, nightguard) is the most widely used treatment for TMJ

and jaw muscle problems. However, the actual effectiveness of these splints is unclear. If an oral splint is recommended, it should be used only for a short time and should not cause permanent changes in the bite. If a splint causes or increases pain, stop using it and tell your healthcare provider. Avoid using over-the-counter mouthguards for TMJ treatment. If a splint is not properly fitted, the teeth may shift and worsen the condition.

Experts convened at a NIH Technology Assessment Conference held in 1996 concluded that reversible approaches, along with adequate measures of pain relief, are the treatments of choice for most TMJ diseases and disorders. TMJ patients should be cautious in trying to seek a cure for their TMJ problems, but rather seek treatments that help manage their pain.

Irreversible Treatments

According to the National Institute of Dental and Craniofacial Research, of the National Institutes of Health, irreversible treatments have not been proven to work and may make the problem worse. Examples of irreversible treatments are:

• Manual adjustment of the bite by grinding the teeth.
• Mandibular repositioning splints which move the jaw, ligaments and muscles into a new position.
• Extensive dental work such as crown and bridge work to balance the bite.
• Orthodontics
• Surgical procedures
• Replacement of the jaw joint(s) or disc(s) with TMJ implants should be considered only

as a treatment of last resort. TMJ implants are intended to improve jaw function. Pain alone is not a reason to undergo a TMJ replacement procedure; often, after surgery, the pain level stays the same or even increases. TMJ implants may also cause permanent damage. Some of these devices may fail to function properly or may break.

Persons undergoing more than two surgeries on the jaw joint generally have a poor outlook for normal, pain-free joint function after additional surgery.

Since more studies are needed on the safety and effectiveness of most treatments for temporomandibular joint and muscle disorders, experts strongly recommend using reversible treatments. Even when the TMJ problem has become chronic, most patients still do not need aggressive types of treatment.

Prevention

There is currently no evidence that such conditions can be prevented.

Chances of Developing Temporomandibular (Jaw) Joint Diseases and Disorders

The National Institute of Dental and Craniofacial Research (NIDCR) of the National Institutes of Health (NIH) indicates that over 10 million people in the United States suffer from TMJ problems at any given time. Both men and women experience TMJ problems; however, 90 percent of those seeking treatment are women in their childbearing years.

Recent research indicates that more women seek medical care for a TMJ problem than men, and women are more likely than men to report ongoing pain. Physiological differences in pain signal processing may explain why more women suffer from TMJ conditions than men.

Related Problems

A study conducted by The Lewin Group prepared for the Agency for Healthcare Research and Quality concluded that many TMJ patients have other health problems. These may include Fibromyalgia, sleep disorders, Irritable Bowel Syndrome, chemical sensitivity, Mitral Valve Prolapse, and Hypermobile Joints. The relationship between these conditions and others and TMJ diseases and disorders needs further research. Moreover, certain medical conditions such as Ehlers-Danlos Syndrome, Dystonia, Lyme Disease and Scleroderma also may have an effect on the TMJ.

Researchers generally agree that TMJ diseases and disorders fall mainly into three categories. A person may have one or more of these conditions at the same time.

• Myofascial pain. This refers to discomfort or pain in the muscles that control jaw function and can also extend to the muscles in the neck and shoulders.
• Internal derangement of the joint. This involves displacement of the disc that acts as a cushion between the skull and lower jaw.
• Inflammatory joint disease.
  • Arthritis. This is an inflammatory condition that affects a joint. Various forms of Arthritis can affect the TMJ such as Degenerative (Osteoarthritis), Rheumatoid, Traumatic, Infectious, Psoriatic, and Gouty Arthritis.
  • Synovitis This is an inflammatory condition of the synovial membrane. The synovial membrane lines the joint and produces a fluid that lubricates the joint.

Some people may have other health conditions that may co-exist with TMJDs, such as:

• Allergies
• Cardiac arrhythmias
• Chronic fatigue syndrome
• Chronic headaches – migraine & tension
• Dizziness
• Ear pain
• Endometriosis
• Fibromyalgia
• Generalized pain conditions
• Interstitial cystitis
• Irritable bowel syndrome
• Meniere’s Disease
• Movement disorders
• Multiple chemical sensitivity
• Rheumatoid arthritis
• Sleep disorders or disturbances
• Tinnitus (ear ringing)
• Vestibular Disorders
• Vulvodynia

Even if a patient is diagnosed with one or more of the conditions listed above, he or she may or may not experience pain in the jaw area and/or have jaw dysfunction. Research has found that many people who have these conditions are completely unaware of them and lead perfectly healthy lives.

Conditions that may produce similar signs and symptoms as TMJDs (pain and/or jaw dysfunction) and can lead to misdiagnosis include:

• Atypical (vascular) neuralgia
• Hypo- and hyperkinesia (abnormal jaw movements)
• Lyme disease
• Myositis (muscle inflammation)
• Myositis ossificans (calcification in a muscle)
• Otitis (earache)
• Parotitis (salivary gland inflammation)
• Scleroderma (chronic hardening of the skin)
• Sinusitis
• Temporal arteritis (inflammation of the temporal artery)
• Toothache
• Trigeminal neuralgia
• Trotter’s syndrome (nasopharyngeal carcinoma )

Expected Outcome

Some TMJ problems improve on their own, without treatment, within weeks or months with simple home therapy. For others, symptoms worsen over time and develop into long-term, persistent and debilitating pain. Most people with TMJ problems have relatively mild or periodic symptoms.

Notable Experts

There is no specialty because this area lacks the science necessary for the American Dental Association and American Medical Association to establish a specialty. Although a variety of healthcare providers advertise themselves as TMJ specialists, treatments available today are based largely on beliefs, not on scientific evidence.

As we learn more about the TMJ and its associated structures, many in the healthcare community are reassessing their treatments and the basis upon which they were developed. It is clear that the various temporomandibular diseases and disorders are far more complex than was previously believed.

References

1. Agency for Healthcare Research and Quality. (2001). Study of the per-patient cost and efficacy of treatment for temporomandibular joint disorders. (AHRQ Publication No. 290-96-0009). Washington, D.C.: The Lewin Group.

2. Centers for Disease Control & Prevention. (1998). Taking part in research studies: What questions should you ask? Retrieved May 9, 2005, from http://www. cdc.gov/hiv/pubs/brochure/unc3bro.htm

3. Cowley, T., & Laskin, D. (2002). A plea for the TMD patient. Dental Abstracts, 47 (5), 188-189.

4. Landro, L. (2002, December 5). Assessing safety of clinical trials. The Wall Street Journal, pp. D3.

5. Mercuri, L. (1991). Fixation on the Disc. Practical Reviews in Oral and Maxillofacial Surgery [cassette]. Birmingham: Oakstone Medical Publishing.

6. National Institutes of Health: National Institute of Dental and Craniofacial Research. (1993). Estimated prevalence and distribution of reported orofacial pain in the United States. Journal of the American Dental Association, 5 (10), 115-121.

7. National Institutes of Health Technology Assessment Conference Statement. (1996). Management of temporomandibular disorders. Washington, D.C.: Government Printing Office.

8. National Institutes of Health: National Institute of Dental Research. (1996). TMD: Temporomandibular disorders. (NIH No. 94-34870). Washington, D.C.: Government Printing Office.

9. Schmid, J. M. (2000, September). Should you join a clinical trial? Ladies’ Home Journal, 117 (9), 110. Christensen, D. (2001). Moving temporomandibular joint research into the 21st century. TMJ Science, 1 (2), 9-18.

External Links

NIH, "Less Is Often Best In Treating TMJ Disorders"

NIH "TMJ Disorders"

The TMJ Association, Ltd.