Jaw pain—often accompanied by a feeling that your jaw has come unhinged and is "clicking" whenever you open your mouth—is an old complaint. And fittingly, it has a jaw-breaking name: temporomandibular disorder (TMD), which has replaced a previous jaw-breaking name, temporomandibular joint syndrome, or TMJ. After low back pain, it is the most common kind of pain in the musculoskeletal system. It is a major cause of missed work and medical bills. It's estimated that 20 million American adults experience some form of TMD, and more than 5 million seek treatment for it each year. Women are particularly susceptible.
The jaw hinge connects the lower jaw (mandible) to the temporal bone on each side of the head. Sometimes this joint hurts, clicks, or locks painfully. Jaw muscles may become sore, making it hard to chew. Pain may radiate to the facial and neck muscles, the head, ears, and teeth; it may persist around the clock. It may take both a dentist and a physician to diagnose TMD.
Causes and controversies
There are many theories about the causes of TMD. Some of the obvious ones are injury to the jaw or some form of arthritis in the joint. Genetic factors may play a role. In fact, TMD is very hard to diagnose and treat, probably because it may be a lot of different problems that vary from person to person. Some dentists blame grinding or clenching the teeth (bruxism), especially at night. Dislocation of the disk that cushions the jaw joint is another possible culprit. Emotional stress is often cited as a cause of both teeth grinding and TMD. You may tend to clench your jaw when under stress. Certainly the pain of TMD, if it persists, can cause emotional stress. Gum chewing, nail biting, and eating chewy foods or crunchy candies might also contribute. Malocclusion (teeth that don’t fit together properly) can throw the jaw out of line, though researchers now doubt that this has much to do with TMD. Bad posture, particularly thrusting the chin forward, can strain the neck muscles and those of the jaw and thus contribute to TMD.
Unfortunately, after years of study, there is still no consensus about the causes of TMD or what treatments are most effective.
What to do first
The first line of treatment is self-care. Over-the-counter pain relievers can reduce pain and muscle spasm. Eat soft foods. Give up hard bagels, gummy candies, and dried fruit for a while. Cut your food into small pieces. Don't chew gum. Squelch cavernous yawns (hold your chin in place with your fingers). Cold or hot compresses to the jaw may help; you can try alternating ice and heat. Massage your jaw muscles and temples. Let your jaw hang slightly when not chewing, swallowing, or speaking.
Perform gentle stretches and jaw-relaxation techniques. Slowly open and close your mouth; puff air between your lips to keep your teeth apart. Correct any habit that may be contributing to your problem. For instance, beware of gripping a phone between your shoulder and cheek during a long conversation, or carrying a heavy shoulder bag for long periods on the same shoulder.
What your dentist can do
If your symptoms don't go away with these measures, consult your dentist. In the past, correcting malocclusion by grinding down a few tooth surfaces was regarded as a good treatment for TMD. Mouth splints (also called mouth guards or bite plates, worn while sleeping) can help stabilize the bite and eliminate nocturnal tooth grinding—which is desirable anyway. But most recent studies indicate that neither mouth splints nor correcting malocclusion are very good at relieving TMD. Researchers at the University of Washington in Seattle found that mouth splints were no better than the self-help methods described above. A review article from the University of Pittsburgh School of Medicine last year found that grinding tooth surfaces to correct malocclusion was no use against TMD, but that mouth splints may be beneficial. If you try a splint, a study in the Journal of the American Dental Association found that low-cost athletic mouth guards often work as well as made-to-order devices.
If emotional problems and stress are contributing to your TMD, professional counseling may help. In a 2007 study researchers found that people suffering from acute TMD responded well to relaxation training, biofeedback, distraction therapy, and related techniques. If your condition has resulted in chronic pain, this kind of therapy may prove useful.
Keep in mind that TMD may improve with time and go away on its own. If it does not, you may want a referral to an orofacial pain management clinic or TMD center affiliated with a hospital or university. If nothing like that is available in your area, your dentist may refer you to other professionals, such as a physical therapist, oral surgeon, or neurologist.
At least two small but well-designed studies have found that acupuncture can be useful in reducing pain and other symptoms of TMD, at least in the short term. If your pain persists, this is worth trying.
At the opposite end of the medical spectrum is surgery, which some practitioners advise for severe and persistent cases. Be very cautious about this. Jaw implants are a bad idea, and jaw surgery can have disastrous results. Most TMD experts say surgery has no place in TMD treatment. Consider it only if your pain is disabling; even then, get a second and possibly third opinion. Surgery should be only a last resort.