THE TRUTH ABOUT TMJ
Many patients come to us with questions as to whether or not they have TMJ. On a strictly factual basis, our response would always be, yes, they have TMJ—two of them, in fact! TMJ is an abbreviation for temporomandibular joint, also known as the jaw joint. The TMJ acts as a hinge connecting the upper and lower jaws, so that the jaws can function together when you eat and speak. Sometimes a patient can have problems with one or both of their TMJ’s and these problems are properly termed temporomandibular dysfunction (TMD). TMD can affect either or both of your joints, and may be as minor as mild soreness of the facial muscles, to as severe as debilitating pain and locking up of the joint.
Your TMJ is a ball-and-socket joint with the ball (called the condyle) at the top of your lower jaw (called the mandible) resting in the socket (called the glenoid fossa) of your upper jaw (called the maxilla), which is fused to your skull. Your TMJ's are located just in front of your ears. All healthy joints contain cartilage, and the TMJ is no exception. A wafer of cartilage cushions the contacts, and the entire joint is guided and powered by its surrounding muscles and ligaments.
TMD is quite simply the disruption of one or both of your TMJ’s. TMD is an inflammatory disorder, with all the accompanying signs and symptoms of inflammation: pressure, swelling, pain, and loss of function. The inflammatory changes that can occur inside the joint may cause muscle spasms, fluid build-up, ligament sprains, or (in severe cases) dislocation.
There are many factors that either alone or in combination can contribute to TMD. Malocclusion (misaligned bite), trauma, and, indirectly, stress through bruxism (grinding your teeth) or clenching can all cause TMD. The signs and symptoms of TMD are many. Besides pain, you may notice tightness in your jaw muscles that might be accompanied by a burning sensation, an uneven bite, or a grating sensation when you open or close. These symptoms may be particularly recognizable when you wake in the morning and, depending on the severity of your condition, may resolve somewhat as the day progresses. This is especially likely if you are bruxing in your sleep. If you are clenching during the day (an activity you may not be aware of for long periods of time), your symptoms will probably not subside. It is highly unlikely that you would grind your teeth while awake because this behavior is so noticeable. Other signs of TMD include grating, clicking, or popping sounds when you open (usually not when you close) that can be quite loud; a limited ability to open (called trismus); and lock-jaw in the open or closed position.
The first step in treating TMD is a thorough examination. You will be asked to fill out a questionnaire detailing your TMJ history. The dentist will need a panoramic x-ray image of your joints to look for any bony changes in them that may indicate TMD. He will also pay special attention to the chewing surfaces of your teeth to look for signs of grinding. Cracks in your teeth may also be signs of bruxism. The dentist will also manipulate your TMJ’s to sense for any roughness or interruption in their movements.
Once he has gathered all the information needed to assess your TMJ’s, the dentist will discuss your case with you and review available treatment options. These may include staying on a soft diet, wearing an appliance called an occlusal splint or biteplane to alleviate nocturnal bruxism, or the use of prescription muscle relaxants. If the dentist feels your TMD is particularly advanced, he may recommend a referral to an oral surgeon. Reshaping your teeth with slight adjustments or crowning them can sometimes correct instances where misalignment of your bite is limited. In cases of severely misaligned bite, referral to an orthodontist may be indicated.
Remember that you do not necessarily have TMD just because you may have some of the characteristic signs. Some patients go through their entire lives with mild clicking or limited opening, while functioning normally and without any complaints or deterioration. If you are in this situation, the dentist will monitor your joints closely at each routine oral examination to check for any changes that may suggest some deterioration in them. If this occurs, proper treatment will be initiated at that time.