Temporomandibular Joint (TMJ) Disorder (TMD)

1. What is it?
2. Symptoms
3. Diagnosis
4. Expected Duration
5. Prevention
6. Treatment
7. When To Call
8. Prognosis

What Is It?
Temporomandibular disorders (TMDs) describe several problems that affect your temporomandibular joint (TMJ), or jaw joint, and the muscles of the face that help you to chew. If you place your fingers just in front of your ears and open your mouth, the movement you feel is your TMJ. It is a small ball-and-socket joint consisting of the ball, called the condyle; the socket, called the glenoid fossa; and a small, fibrous disk, which acts as a shock absorber between the ball and socket.

Studies estimate that between 20% and 30% of people experience the symptoms of TMDs. Although there is some disagreement, it appears that more women than men develop TMDs. The reason isn't clear, but one theory is that the collagen that holds the disk in position between the ball and socket is structurally different in women. This may cause more women to have dislocated disks, which can lead to TMDs. In addition, some studies have suggested that hormones like estrogen may affect the way women perceive pain.

TMD is a general term, not a specific condition. If your dentist tells you that you have TMD, it's a lot like your doctor telling you that you have a knee problem. Often, people will say they "have TMJ." TMJ is the name of the joint, not a disease or condition.

The causes of TMD are not understood completely but can include:

? Trauma to the jaw, either a direct blow to the joint or prolonged
   clenching or grinding of the teeth (bruxism)
? Tension or stress, which triggers muscle spasms
? Poor alignment of the teeth (malocclusion)
? Arthritis of the temporomandibular joint
? Tumors of the temporomandibular joint
? Also, some general medical problems, such as rheumatoid
   arthritis or osteoarthritis can affect the temporomandibular joint.

Symptoms
Symptoms of TMD include:

? Pain or tenderness in the area in front of your ear, especially when
   you chew, speak or open your mouth wide
? An occasional feeling of the jaw being stuck open or closed
? Facial-muscle spasms that make it difficult to open your mouth or
   that make it feel as though your teeth don't meet normally
? Clicking, popping or cracking sounds or a grating sensation in the
   jaw when you open or close your mouth
? Headaches that tend to start in the front of the ear and spread to
   the rest of the head or neck

Diagnosis

An important part of the diagnosis is reviewing the history of your problem: how long you've had symptoms and if they occur at certain times (such as only when eating or only at night).

Your dentist will look at the way your jaw moves, examining your teeth for signs of habits such as clenching or grinding (bruxism) and probing the TMJ and the muscles of your jaw and neck for signs of tenderness. He or she might use a stethoscope to listen for joint sounds that would suggest a disorder involving the disk or bones of the joint.

Your dentist will determine whether your problem is a muscle disorder or if it involves the bones or disk of the joint. Usually, a regular X-ray or a panoramic X-ray can rule out a serious disorder within the joint.

If a more detailed view of the joint is necessary, magnetic resonance imaging (MRI) or a computed tomography (CT) scan might be used.

The exam also will be used to check for other conditions that could be causing your symptoms, including arthritis, sinus infections, toothache, earache and neurological problems. All of these conditions have symptoms similar to those of TMDs.

When your dentist or doctor has established that you have a TMD, he or she will be able to tell you what type of TMD you have and how it can be treated.
 
Expected Duration
TMDs can last only for a few weeks when they are caused by trauma to the jaw, for example. Other types of TMD, such as a problem caused by arthritis or bruxism, can last months or even years, depending on how they respond to treatment.

Prevention

A TMD caused by bruxism can be prevented by using a nightguard, which is a molded piece of plastic used to reduce the pressure on the jaw. If you clench your teeth due to tension or anxiety, working with a psychologist or undergoing relaxation therapy or biofeedback may help prevent TMJ problems.

Treatment
The treatment of a TMD depends on its cause.

Most TMDs are related to sore muscles that can spasm periodically. This type of TMD usually responds to conservative treatment, which can include any or a combination of the following:

? Soft diet — Avoid hard or crunchy foods. Cut food into small pieces
   and chew with your back teeth rather than biting into large items,
   such as a thick sandwich, with your front teeth.
? Physical therapy, which can include heat, massage and ultrasound
? Intraoral plastic splints (also known as nightguards), which are
   similar to mouth guards, to control teeth clenching and grinding
? A nightguard to help stop teeth clenching and grinding
? Stress reduction therapy, including biofeedback
? Over-the-counter pain relievers
? Prescription anti-inflammatory medications
? Prescription muscle-relaxing medications
? Bite adjustment, which might include reshaping teeth slightly so
   that they meet properly
? Replacement of missing teeth
? Orthodontic therapy

If conservative measures do not provide relief, surgery might be considered.

Often, surgery can be done arthroscopically, through two or three very short incisions. A tiny camera is inserted through one incision and surgical instruments are inserted through one or two other incisions. Inflamed tissue is removed and the joint is flushed.

If the jaw is locked shut because of a dislocation or scarring within the joint, open surgery might be necessary. The jaw can be repositioned and the obstructing disk can be repositioned or removed.

When To Call A Professional
Call your doctor if:

? Your jaw movement is limited.
? You have injured your jaw and are taking over-the-counter pain
   medication, but the pain doesn't go away after several days.
? You have swelling in the area of your TMJ.
? Jaw pain keeps you up at night or makes eating difficult.

Prognosis
With proper care and control of habits, the symptoms should go away. Some cases may go away in less than a month. Other cases, such as those involving arthritis or people with long-standing or severe bruxism, may take longer.

Additional Information

American Academy Of General Dentistry
211 East Chicago - Suite 900
Chicago, IL 60610-1999
Toll-Free: (888) 243-3368
Fax: (312) 440-0559
http://www.agd.org/

National Institute of Dental and Craniofacial Research
National Institutes of Health
Bethesda, MD 20892-2190
Phone: (301) 496-4261
E-Mail: nidcrinfo@mail.nih.gov
http://www.nidcr.nih.gov/

American Association of Oral & Maxillofacial Surgeons
9700 West Bryn Mawr Ave.
Rosemont, IL 60018-5701
Phone: (847) 678-6200
E-Mail: inquiries@aaoms.org
http://www.aaoms.org/

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