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Articles » TMD-TMJ (Jaw Disorders): NWHIC

TMD-TMJ (Jaw Disorders): NWHIC

Article title: TMD-TMJ (Jaw Disorders): NWHIC

Conditions: temporomandibular disorders, jaw

Source: NWHIC

TMD/TMJ (Jaw Disorders)

What is TMD?
What is TMJ?
What are the causes of TMD?
What are the signs and symptoms of TMD?
How do you diagnose TMD?
How do you treat TMD?

What is TMD?

TMD, or temporomandibular disorders, are a group of conditions affecting the temporomandibular joint (TMJ) and the muscles involved in chewing. These disorders occur more frequently in women than men, and it has been estimated that approximately 10 million women in the USA suffer from chronic face or jaw joint pain. There are many possible causes of these disorders, and diagnosis can be confusing and difficult. Treatment is usually conservative and reversible, and may require many different medical specialists. Occasionally injections and surgery are necessary for chronic pain and disability.

What is TMJ?

The temporomandibular joint's name is derived from the two bones that it connects. It joins the bone at the side of the head (temporal bone) to the lower jaw (mandible). This joint can be felt on either side of the head when placing a finger in front of each ear and opening the mouth.

Upon opening the mouth, the rounded end at the top of the lower jaw, known as the condyle, will glide along a groove in the temporal bone. Upon closing the mouth, the condyle will slide back to its original position. In order to preserve a smooth gliding motion, a very thin soft disc lies between the condyle and the temporal bone. This disc acts as a shock absorber for the TMJ during daily functions such as chewing, talking, and yawning. It is during these actions that the TMJ and its surrounding muscles may be affected, resulting in any one of a number of uncomfortable conditions including TMD.

TMD Categories researchers have found that temporomandibular disorders generally fall into three main categories:

  • Myofascial pain. This is the most common form of TMD, which involves discomfort or pain in the muscles that control jaw function, as well as the neck and shoulder muscles.

  • Internal deranqement of the TMJ. This involves a dislocated jaw, displaced disc, or injury to the condyle.

  • Degenerative joint disease. This includes diseases such as osteoarthritis or rheumatoid arthritis in the TMJ.

What are the causes of TMD?

Severe injury to the jaw or TMJ can cause TMD. For example, a heavy blow can fracture the bones associated with the joint, or damage the disc. This may result in a disruption of smooth jaw motion causing pain or locking of the jaw during movement. Other causes of TMD are less clear. A poor bit (malocclusion) orthodontic treatment, jaw clenching, teeth grinding, as well as physical and mental stress have all been linked to TMD. Unfortunately, their roles as definite causes have not yet been determined.

What are the signs and symptoms of TMD?

Pain, particularly in the chewing muscles and/or the TMJ is the most common symptom of TMD. Other symptoms include the following:

  • Limited movement or locking of the jaw

  • Radiating pain to the face, neck, or shoulders

  • Painful clicking, popping, or grating sounds in the jaw joint when opening or closing the mouth

  • Sudden major changes in the way that the upper and lower teeth fit together

  • Headaches, earaches, dizziness, and hearing problems may also be related to TMD.

It is important to understand that occasional discomfort in the jaw or chewing muscles is quite common. It is usually temporary in duration, and is not generally a cause for concern.

A common sensation in the general population is clicking or popping of the TMJ. Upon opening and/or closing the mouth, one may hear or feel a clicking or popping of the jaw joint. Researchers believe that most people who have clicking or popping of the TMJ probably have a displaced disc within the joint. If the displaced disc causes no pain or locking of the jaw, then typically no treatment is required.

How do you diagnose TMD?

Since the causes and symptoms of TMD are often unclear, diagnosis can be confusing and difficult. In about 90% of cases, the combination of the patient's description of symptoms, dental and medical history, and a physical examination of the face and jaw, can provide useful information for the diagnosis of these disorders.

The physical examination involves feeling the TMJ and chewing muscles for pain or tenderness; listening for clicking, popping, or grating sounds during jaw movement; and observing any limited motion or locking of the jaw while opening or closing the mouth.

Routine dental and TMJ x-rays are not always useful in the diagnosis of TMD, but may be helpful in few patients. Other x-ray techniques such as arthrography (x-rays of the joint using a dye), and magnetic resonance imaging (MRI, which pictures the soft tissues) are usually needed only when the practitioner strongly suspects a condition such as osteoarthritis or internal derangement of the TMJ, or when significant pain persists over time and symptoms have not improved with previous treatment.

How do you treat TMD?

Since most of the discomfort of TMD is temporary, treatment is usually conservative and reversible. Conservative non-surgical treatments do no invade the tissues of the face, jaw, or joint. Reversible treatments do not cause permanent, or irreversible changes to the position of the jaws or teeth. Researchers strongly recommend using the most conservative, reversible treatments possible before considering any invasive treatments.

Simple self-care practices such as special relaxation and stress-reduction techniques can be used in order to help patients relieve the pain that is often a TMD symptom. Eating soft foods, applying moist heat packs, and avoiding extreme jaw movements are useful measures that can help ease TMD symptoms. Other conservative, reversible treatments include physical therapy that focuses on gentle muscle stretching, and the short-term use of muscle relaxants and anti-inflammatory drugs. Occasionally, a psychiatric/psychological or neurological condition is believed to be the cause of TMD, and then referrals to the appropriate clinicians are recommended.

In some cases, an oral appliance, known as a splint, may be necessary. The splint is a plastic mouth guard that fits over the upper or lower teeth. It acts to help reduce clenching or grinding of the teeth, thereby easing muscle tension. It should not be used for a long period of time, nor should it increase pain, or cause permanent changes in a person's bite.

Other less conservative treatments of TMD include injecting medications directly into the joint or affected muscles, removing scar or destroyed tissue from the TMJ, or conducting surgery on the jaw bone to improve the relationship between upper and lower teeth (orthognathic surgery). Surgical treatments are often irreversible and as with most surgical procedures, there are usually significant risks involved. Surgery may result in an increased level pf pain, discomfort, or cause permanent damage to the jaw and TMJ. Typically, conservative therapy is recommended prior to any surgical procedure. Only if multiple conservative therapies have failed should surgery be considered.

Prior to any surgery, it is strongly advised that one clearly understands the reason for this type of treatment, its benefits, and possible risks. Furthermore, one should seek at lease a second opinion prior to consenting to any possibly irreversible surgical procedure.

For More Information...

You can find out more about TMD/TMJ by contacting the following organizations:

National Institute of Dental and Craniofacial Research

National Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse

Contributing to this FAQ on TMD/TMJ: University of Michigan's Women's Health Program, a National Center of Excellence in Women's Health, sponsored by the Office on Women's Health in the Department of Health and Human Services'

All material contained in the FAQs is free of copyright restrictions, and may be copied, reproduced, or duplicated without permission of the Office on Women's Health in the Department of Health and Human Services; citation of the source is appreciated.

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Publication date: 1998



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