Millions of people clench and grind their teeth without realizing it, particularly while they’re sleeping. Both habits can escalate into serious pain and problems of the temporomandibular joint, or TMJ, which joins the jaw to the skull. And they are far more common in times of stress.

Illustration: Jayachandran / Mint

“TMJ and Wall Street go hand in hand, especially lately," says Anthony Chillura, a long-time dentist in New York City’s financial district. “Some people get ulcers. Some people get high blood pressure. Some manifest their stress dentally."

While most people clench or grind their teeth — a condition known as bruxism — from time to time, about 10% suffer from TMJ problems — and those can set in suddenly. Sarah Aroeste, a professional singer, woke up one morning last summer with shooting pain every time she tried to open her mouth. “It was excruciating, and it happened right before an important concert," she says. The pain persisted for weeks until a combination of a mouth guard, painkillers, Valium, a liquid diet and massage made it ease.

TMJ disorder can mimic migraine headaches, earaches, sinus infections and tooth abscesses. It can cause dizziness, ringing in the ears and muscle pain that radiates down the neck and shoulders. Adding to the frustration, it’s often hard to get insurance coverage for treatment, since medical insurers view it as a dental problem, and dental insurers view it as medical.

In some people, the real culprit is a misaligned bite — either from birth or a trauma such as a fall or a collision in sports. “It’s like you’re chewing with a limp," says Harold Gelb, an oral orthopaedist in Manhattan. He says such problems can build for years and flare up under stress.

Other people “brux" only when they’re under stress, especially during times of change, like a divorce or financial crisis, says Andrew S. Kaplan, another Manhattan TMJ expert and former president of the American Academy of Orofacial Pain. “Once they get acclimated to the new situation, the grinding sometimes stops."

Much of the tension comes out at night, when higher centres of the brain that keep it in check during the day are asleep, says Noshir Mehta, director of the Craniofacial Pain Center at Tufts University School of Dental Medicine.

A clenched jaw can exert up to 300 pounds of pressure, which can wear teeth down and crack them, particularly where there are cavities or old fillings. Over time, arthritis, inflammation and degenerative changes can occur in the jaw joint. The disc in the joint can shift and make clicking or popping sounds. It can also “lock" out of place, making it impossible to open the mouth more than an inch or so, as it did with Aroeste.

Women have more TMJ problems than men — possibly because the jaw muscle bulks up in men, whereas it becomes dysfunctional in women, says Dr Mehta. He notes that people taking antidepressants are also more prone to bruxing, for reasons not well understood.

If you suspect that you’re bruxing — if you wake up with a sore jaw or your partner complains about a grinding noise — it’s a good idea to check with a dentist before it escalates.

The most common treatment for TMJ is a night guard that fits between the teeth and makes grinding more difficult. Custom-made appliances cost anywhere from $300 (around Rs14,430) to $1,800. Devices that correct misaligned bites can cost $2,500. Over-the-counter mouth guards cost as little as $20 and are better than nothing, some dentists say.

Once TMJ problems have set in, anti-inflammatories or muscle relaxants can be helpful. Studies at Tufts have shown that magnesium citrate — 250-400mg daily — can also help relieve muscle tension.

Physical therapy — with massage, ultrasound or electrogalvanic stimulation — can help relax contracting muscles, and exercises can help keep them limber. Injections of Botox can temporarily weaken jaw muscles that are in spasm. A trained dentist or physical therapist can relieve activated trigger points with an injection of saline or even a dry needle. Massaging the trigger points can also keep them from becoming active.

In rare cases, surgery — either open or arthroscopic — may be used to reposition the TMJ disc, but that’s generally a last resort. Some specially trained dentists now can manipulate the disc back into position in an office procedure.

Learning some new habits can be just as effective. If you work at a computer, keeping your keyboard low and your monitor high — propped up on phone books if necessary — will straighten your posture and keep your chin from jutting forward.

Avoid sleeping on your stomach, which can strain your neck and jaw muscles. Try reducing your stress with exercise, yoga or meditation.

Biofeedback techniques can teach you to deal with it differently. In one method, electrodes are attached to the patient’s jaw and the level of muscle tension is displayed on a computer monitor. The patient learns relaxation techniques to bring down the level of tension. Portable gizmos rest in the back of your jaw and emit a beep or a bad taste if you try to close it.

Try this no-cost, low-tech tip: Get in the habit of resting your tongue behind your upper teeth and closing your lips as you go about your day. That will naturally keep your jaw open and at ease.

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