Mysteries of TMD

Biting Pain

Dec. 4, 2000 -- At work, Deborah Zee, 45, picks and chooses whom to speak to and for how long. She never attends loud concerts, and when she looks at a menu in a restaurant, she decides what to order based not on what she wants to eat, but "how much I want to suffer."

Zee, like more than 10 million Americans, most of whom are women, suffers from temporomandibular disorder (TMD), a collection of medical and dental conditions that affect primarily the temporomandibular -- or jaw -- joint and surrounding muscles, nerves, and tendons. TMJ, an older name for the disorder, now usually refers only to a disease or disorder of the joint itself.

Unlike other joints in the body, the jaw moves up and down, forward and backward, and from side to side. It enables us to chew, talk, yawn -- even kiss. Until one day, it doesn't -- or at least not without pain.

For Zee, the pain that began in her 20s and worsened until it became what she describes as "your worst headache, earache, and toothache combined," means she no longer indulges in long conversations or submarine sandwiches. Even noise is a problem: it sparks tinnitis, or ringing in the ears.

For more than a decade, doctors tried and failed to discover what caused Zee's pain. She was variously diagnosed with multiple sclerosis, migraine headaches, rheumatoid arthritis, lupus, PMS, and depression.

Then one day, a drunken driver rear-ended the car she was driving, and her head slammed into the steering wheel. After the accident, the pain she'd suffered for years became unbearable. An MRI showed that the soft disc, a shock absorber of sorts, that lies between the temporal bone at the side of the head and the condyles, the rounded ends of the lower jaw, had been knocked out of place and torn. Surgery to repair the damage failed, and two years ago Zee received an artificial joint implant in her jaw.

On the whole, she says, her quality of life has improved, thanks in large part to a new arthritis drug, Vioxx. But on bad days, the inflammation can be terrible, causing her face to bulge out and her eyes to swell shut.

The most common symptom of TMD is pain in the jaw joint or the muscles when chewing, according to the NIH's National Institute of Dental Research. Other symptoms include clicking, popping, or grating sounds in the jaw when opening or closing the mouth, or a change in the way the upper and lower teeth fit together. TMD patients also may suffer limited movement or locking of the jaw, headaches, earaches, dizziness, or ringing in the ears.

But because TMD includes so many different conditions, its causes vary widely and in most cases are simply unknown. "TMD is really a garbage term," says David Cottrell, MD, associate professor and director of the Oral Maxofacial Residency Program at Boston University Medical School. "It could be one of 15 different things. In most cases, we don't know the exact cause." Nor do researchers know why the disorder strikes women far more frequently than men. Hormones may play a role because patients often report improvement during pregnancy, explains Cottrell.

Rheumatoid arthritis and Lyme disease also can cause TMD because these diseases affect joints. So can psoriasis, a chronic skin disorder that can have several components, such as scaly patches, but also may cause arthritis. Trauma, such as the car accident that injured Zee, is another culprit, although Zee says she believes undiagnosed arthritis already had weakened her jaw and the blow she received "finished off" the disc.

Oftentimes, stress is to blame, as along with stress come such habits as teeth grinding and jaw clenching. And in a recent study, poor posture seemed to be at the root of the problem. An Air Force study published in the February 2000 issue of the Journal of the American Dental Association showed that posture training reduced symptoms by 42% in a group of patients who had suffered for at least six months from TMD.

While causes of TMD remain elusive, most TMD sufferers can find some relief in any number of treatments. Cottrell estimates that more than 80% of his patients recover on their own once they understand the problem and are careful about what they eat and how they open their mouths. Ten percent find relief by wearing a plastic mouth guard during the night that prevents jaw clenching or teeth grinding during sleep.

Still, some patients are more difficult to treat, and in the end they may need jaw surgery. However, Kenneth Gruber, MD, chief of the chronic diseases branch of the Dental and Cranial Facial Research at the NIH, says surgery should be the very last resort. "Our recommendation is, generally don't do anything radical or irreversible," Gruber tells WebMD.

Conservative approaches include eating soft foods, applying heat or ice packs, and avoiding extreme jaw movements like wide yawning, singing, gum chewing, or talking while cradling a telephone between your shoulder and jaw. Physical therapy and medications, such as muscle relaxants, anti-depressants, corticosteroids, and pain pills often are prescribed, and newer medications such as the Cox-2 inhibitors are very effective.

If, like Zee, conservative, reversible treatments don't do anything to quell the symptoms, it may be necessary to consult an oral and maxillofacial surgeon for further tests. But experts warn that if your jaw is opening and closing, you probably don't need surgery.

As for Zee, steaks, chewing gum, and salads will probably never be part of her diet again. Still, she says, "I've been fortunate. The quality of my life has improved immensely."