Thursday, July 15, 2004

Understanding Temporomandibular Joint (TMJ) Disorder Although you use it hundreds of times each day, you may never give a second thought to your temporomandibular joint, or "TMJ" for short. This complex joint connects your lower jaw (called the mandible) with the temporal bones of your skull, found on each side of your head in front of each ear. A small disc of cartilage separates the bones so that the mandible can easily move every time you chew. The TMJ is one of the most complicated joints in the human body. Anything that causes a change in its shape or function can bring on head, facial and jaw pain that is known as a TMJ disorder. Typically, a patient suffering from a TMJ disorder experiences headaches, soreness in the chewing muscles and clicking, stiffness or locking of the jaw joints," said Charles Tentinger, D.D.S., an oral surgeon at Marshfield Clinic. "Pain may also spread to the ears, neck or shoulders." In most patients with a TMJ disorder, pain results from displacement of the cartilage disc that causes pressure and stretching of the associated sensory nerves. "The most common TMJ disorder is the result of habitual clenching, gritting or grinding of the teeth or jaw (also called bruxism)," Dr. Tentinger said. "Less commonly, the condition may be related to trauma from an injury or accident." Many people may not even realize they grind their teeth, especially if they do so in their sleep," added Weiguang Ma, D.D.S., M.D.S., Ph.D., an oral surgeon at Marshfield Clinic. "But habitually doing so increases the wear on the cartilage lining of the joint and it doesn't have a chance to recover." Psychological stress, anxiety and other related factors play a role in TMJ disorders. "In addition to physical, anatomic reasons that can be clearly people identified and measured - such as displaced cartilage, for example - most TMJ patients I see are undergoing a great deal of stress or may have a psychiatric illness or other health issue that contributes to their condition," said Jeffrey Davis, D.D.S., also an oral surgeon at the Clinic. "This makes sense when you consider how many of us brace a muscle when we feel stress. For some people, it's the shoulder or neck muscles; for others, it is the teeth and jaw area." While research has yet to determine why, TMJ disorders most commonly are seen in women, typically in their childbearing years. "For every male patient, I see 20 females with this condition," said Dr. Davis. "Although we can speculate as to why women in this age group more often experience TMJ disorders, we don't have a factual explanation for it." "Some theories relate it to the ways women may deal with stress; others say it may be hormone related, but we honestly don't know why more women than men suffer from TMJ syndrome," said Bernadette Wilson, D.D.S., M.D., another of the Clinic's oral surgeons. The good news about TMJ is that, in the majority of cases - up to 80 percent - this painful condition can be relieved through conservative, non-surgical treatment that includes thorough patient education. "Seventy to 80 percent of TMJ patients respond well to non-invasive remedies such as resting the muscles and joints by eating a diet of soft foods, becoming more aware of and avoiding clenching or grinding their teeth, using moist heat packs and practicing simple jaw relaxation techniques," said Yvonne DeJean, D.D.S., also an oral surgeon at the Clinic. Additional non-surgical TMJ treatment options include physical therapy; biofeedback with an occupational therapist; non-steroidal, anti-inflammatory medications; or a night guard, splint or other orthotic device that helps patients stop clenching or grinding their teeth while they sleep. "In most instances, relief can be provided without surgical intervention," said Dr. Davis. "A small group of individuals requires minimally invasive surgery, which may be as simple as washing out the joint with salt water. The next stage is arthroscopic manipulation, and the end stage of treatment could be a total reconstruction of the jaw joint." Dr. Davis stressed that surgery is recommended only in advanced cases, for example, if the condition clearly affects a patient's ability to speak or chew. "Perhaps there is acute locking of the jaw joint, or the person has already gone through the realm of conservative therapies without improvement," he said. Source: marshfieldclinic.org