Temporomandibular joint disorders (TMJ disorders) are problems or symptoms of the joints that connect your lower jaw to your skull.

See also: Facial pain

There are two matching temporomandibular joints -- one on each side of your head, located just in front of your ears. The abbreviation "TMJ" literally refers to the joint but is often used to mean any disorders or symptoms of this region.

Many TMJ-related symptoms are caused by the effects of physical and emotional stress on the structures around the joint. These structures include:

• Cartilage disk at the joint
• Muscles of the jaw, face, and neck
• Nearby ligaments, blood vessels, and nerves
• Teeth

For example, daily stress can lead you to clench and grind your teeth, both during the day and at night while you sleep. Clenching means you tightly clamp your top and bottom teeth together, especially the back teeth. The stressful force of clenching causes pressure on the muscles, tissues, and other structures around your jaw.

Many people who clench also grind their teeth. Grinding is when you slide your teeth over each other, generally in a sideways, back-and-forth movement. This action may wear down your teeth and can be noisy enough at night to bother sleeping partners.

Poor posture can also be an important factor in TMJ. For example, holding the head forward while looking at a computer all day strains the muscles of the face and neck.

Other factors that might make TMJ symptoms worse are stress, poor diet, and lack of sleep.

All of these stresses can result in "trigger points" -- contracted muscles and pinched nerves in your jaw, head, and neck. Trigger points can refer pain to other areas, causing a headache, earache, or toothache.

Other possible causes of TMJ-related symptoms include arthritis, fractures, dislocations, and structural problems present since birth.

• Biting or chewing difficulty or discomfort
• Clicking sound while chewing or opening the mouth
• Dull, aching pain in the face
• Earache
• Grating sensation while chewing
• Headache
• Jaw pain or tenderness of the jaw
• Reduced ability to open or close the mouth

TMJ pain and symptoms may need to be checked by more than one medical specialist, such as your primary care provider, a dentist, or an ear, nose, and throat (ENT) doctor, depending on your symptoms. Some dentists specialize in TMJ diagnosis and treatment.

A thorough examination may involve:

• A dental examination to show if you have poor bite alignment
• An MRI of the jaw area
• Feeling the joint and connecting muscles for tenderness
• Pressing around the head for areas that are sensitive or painful
• Sliding the teeth from side to side
• Watching, feeling, and listening to the jaw open and shut
• X-rays to show abnormalities

In some cases, the results of the physical exam may appear normal.

Simple, gentle therapies are usually recommended first. If those don't work, mouth guards and more aggressive treatments may be considered. Surgery is generally a last resort. Fortunately, there are many steps you can take at home long before that point.

Try massaging the various muscles that may be involved. Probe all of the muscles of the face, shoulders, and back of the neck. (Avoid the area around the throat.) Press on the muscles to identify extremely painful points. Massage the painful spot with hard, slow, short strokes. Do this several times a day until the muscle is no longer painful when pressed.

To massage the masseter muscles on each side of your jaw, place your thumb inside your mouth and squeeze the thick muscle in your cheek (toward the back of your mouth) with your fingers. To get at the harder-to-reach jaw muscles inside your mouth, use your index finger to probe for tender areas behind the teeth, and use the finger to massage these spots.

Other home-care therapies, such as moist heat or cold packs on the face, vitamin supplements, or biofeedback are useful for some people. Exercising several times each week may help you relax, strengthen your body, increase flexibility, and increase your ability to handle pain.

Read as much as you can, as opinion varies widely on how to treat TMJ disorders. Get several doctor's opinions. The good news is that most people eventually find something that helps.

MOUTH GUARDS

Mouth guards, also called splints or appliances, have been used since the 1930's to treat teeth grinding, clenching, and TMJ disorders. Many people have found them to be useful, but the benefits vary widely. The guard may lose its effectiveness over time, or when you stop wearing it. Other people may feel worse pain when they wear one.

There are different types of splints. Some fit over the top teeth, while others fit over the bottom teeth. They may be designed to keep your jaw in a more relaxed position, prevent clenching, or provide some other function. If one type doesn't work, another may.

For example, a new type of splint is called the NTI-tss. It fits over just a couple of top, front teeth. The idea is to keep all of your back teeth completely separated, under the theory that most clenching is done by these back teeth. With the NTI splint, the only contact is between the tiny splint and one bottom front tooth.

MORE AGGRESSIVE TREATMENT

Be cautious about any non-reversible treatment method that permanently alters your bite. However, if a mouth guard doesn't work, your dentist may recommend orthodontics to help re-align your teeth.

Reconstructive surgery of the jaw is rarely required. In fact, studies have shown that the results are often worse than before surgery.

Muscle relaxant medications may help. Nonsteroidal anti-inflammatory medications (NSAIDs) help reduce swelling (inflammation) in the jaw stemming from arthritis or other causes.

For additional information, two excellent books are Taking Control of TMJ by Robert Uppgaard and The Trigger Point Therapy Workbook by Clair Davies.

Most cases can be successfully treated, although at first it may be difficult to diagnose the problem and find an effective solution. Some cases of pain go away on their own without treatment. TMJ-related pain may return again in the future. If the cause is nighttime clenching, treatment can be very tricky because it is a sleeping behavior that is hard to control.

Mouth splints are a common treatment approach for teeth grinding. While some splints may silence the grinding by providing a flat, even surface, they may not be as effective at reducing pain or stopping clenching. Splints may be effective in the short-term but could become less effective over time. Splints can also cause changes in your bite.

• Chronic face pain
• Chronic headaches

See your health care provider right away if you are having trouble eating or opening your mouth. Keep in mind that a wide variety of possible conditions can cause TMJ symptoms, from arthritis to whiplash injuries. Experts who are specially trained in facial pain can help diagnose and treat TMJ.

TMJ problems do not fall clearly into one medical area. There are a wide variety of treatment approaches. If you are interested in a massage-based approach, look for a massage or physical therapist trained in trigger point therapy, neuromuscular therapy (NMT), clinical massage, or pain relief, especially for TMJ pain.

Dentists who specialize in evaluating and treating TMJ disorders will typically perform x-ray exams and may use a kinesiograph or EMG (electromyography). They may give you a mouth guard. Surgery is now considered a last resort by most TMJ experts.

• Avoid eating hard foods and chewing gum.
• Drink plenty of water every day and get plenty of sleep.
• Learn relaxation techniques to reduce overall stress and muscle tension.
• Maintain good posture, especially if you work all day at a computer. Pause often to change position, rest your hands and arms, and relieve stressed muscles.
• Use safety measures to reduce the risk of fractures and dislocations.

American Dental Association. TMD/TMJ (temporomandibular disorders). Available at: http://www.ada.org/public/topics/tmd_tmj.asp.

Lobbezoo F. Topical review: new insights into the pathology and diagnosis of disorders of the temporomandibular joint. J Orofac Pain. 2004; 18(3): 181-191.

Simons DC, Travell JG. Myofascial Pain and Dysfunction: The Trigger Point Manual. Vol. 1. Upper Half of the Body. 2nd Ed. Atlanta, GA: Emory University;1998.