The temporomandibular joints (TMJs) connect your lower jaw to your skull. There are two matching 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 refer to any disorders or symptoms of this region. Such problems include popping sounds in the jaw, inability to fully open the mouth, jaw pain, headaches, earaches, toothaches, and various other types of facial pain.

Many TMJ-related symptoms are caused by the effects of physical and emotional stress on the structures around the joint. These structures include the muscles of the jaw, face, and neck; the teeth; the cartilage disk at the joint; and nearby ligaments, blood vessels, and nerves.

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 be noisy enough at night to bother sleeping partners.

Poor posture can also be an important factor. 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 aggravate TMJ symptoms are inability to relax, 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.

• Headache
• Earache (the joint is located right in front of the ears and can easily be interpreted as ear pain; in addition, pain may be referred to the ear from nearby muscles)
• Jaw pain or tenderness of the jaw
• Dull, aching facial pain
• Biting or chewing difficulty or discomfort
• Clicking sound while chewing or opening the mouth
• Grating sensation while chewing
• Reduced ability to open or close the mouth

TMJ pain and symptoms may require evaluation by more than one medical specialty, 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:

• Feeling the joint and connecting muscles for tenderness
• Watching, feeling, and listening to the jaw open and shut
• Sliding the teeth from side to side
• Pressing around the head for areas that are sensitive or painful
• X-rays which may show abnormalities, but can be difficult to read
• An MRI of the jaw area may occasionally be performed
• A dental examination may show mis-alignment of the bite (crossbite, malocclusion)

In some cases, the results of the physical examination 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 considered 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.

Here are some other steps to consider:

• Maintain good posture while working at a computer, watching TV, and reading. Take frequent breaks to relieve stressed muscles.
• Make a habit of relaxing your facial and jaw muscles throughout the day.
• Avoid eating hard foods, like nuts, candies, and steak.
• Drink plenty of water every day and get plenty of sleep.
• Learn relaxation techniques to reduce overall stress and muscle tension in your back, neck, and body.

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

Read as much as you can, as opinion varies widely on the management of TMJ disorders. Get several clinical perspectives. 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 of the teeth, some on the bottom. They may be designed to keep your jaw in a more relaxed position, inhibit 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 inflammation in the jaw stemming from arthritis or other causes of inflammation.

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 initially 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 tends to be cyclical and may return again in the future. If the cause is nighttime clenching, treatment can be particularly 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, their effectiveness at reducing pain or stopping clenching is more controversial. Splints may be effective in the short-term but could become less effective over time. Splints can also cause changes in your bite.

• Chronic headaches
• Chronic facial pain

See your health care provider immediately 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 discipline. 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, particularly as it applies to 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 the patient a mouth guard. Surgery is now considered a last resort by most TMJ experts.

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