Of course you do. Everyone does. In fact, everyone has two TMJs. TMJ stands for temperomandibular joint. Most people more commonly call them their jaw joints and they are the hinges that connect your upper and lower jaws so that they can function together when you eat and speak. Sometimes a patient can have problems with one or both of their TMJs and these problems are properly termed temperomandibular dysfunction (TMD). TMD can affect either or both of your joints and be as minor as mild soreness of the facial muscles to as severe as debilitating pain and locking of the joints in the open or closed position.
Your TMJ is a ball-and-socket joint with the ball (called the condyle) at the top of your lower jaw bone (called the mandible) resting in the socket (called the glenoid fossa) of your upper jaw bone (called the maxilla) which is fused to your skull. Your TMJs are located just in front of your ears. All healthy joints contain cartilage and your TMJ is no exception. A wafer of cartilage called the articular disk lies between the condyle and the glenoid fossa cushioning your joint that is lubricated by synovial (joint) fluid. Your joint is guided and powered by its surrounding muscles and ligaments.
The anatomy of a normal TMJ.
TMD is quite simply the disruption of one or both of your TMJs. 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 your joint may cause spasms of the joint's muscles, fluid build-up within the joint, spraining of its ligaments and (in severe cases) dislocation or tearing of the articular disk. In the latter instance, bone scrapes against bone in the joint causing extensive complications.
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. Malocclusion may cause misalignment within your joint that can lead to TMD. Malocclusion can also be a form of physical strain that induces bruxism in a vicious cycle that spirals steadily downward. Other, severe physical strain such as weight lifting is often associated with clenching. Bruxism and clenching are also known to be reactions to mental and emotional tension you may be experiencing. Parafunctional habits such bruxism and clenching put varying amounts of stress on your TMJ. This stress may result in the inflammation that is TMD. Obviously, blunt trauma such as hitting your chin on the steering wheel in an automobile accident can 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 and 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. The signs of TMJ include grating or 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. Dr. McArdle will need a special kind of x-ray image of your joints known as a panoramic view 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 called wear facets. Cracks in your teeth called craze lines may also be signs of bruxism. Dr. McArdle will also manipulate your mandible and TMJs to feel for any roughness or interruption in their movements.
Once Dr. McArdle has gathered all the information needed to assess your TMJs, he will discuss your case with you and review the available treatment options appropriate to your condition. These may include staying on a soft diet, wearing an appliance called an occlusal splint or nightguard to alleviate nocturnal bruxism, or the use of prescription muscle relaxants. If Dr. McArdle feels your TMD is particularly involved, as when articular disk displacement has caused bony degeneration of your joints, he will refer you to an oral surgeon. Sometimes surgery that only an oral surgeon is qualified to perform may be needed to correct extreme states of TMD. Instances where misalignment of your bite is limited can sometimes be corrected by reshaping your teeth with slight adjustments or crowning them. This may necessitate referral to a specialist in this field called a prosthodontist. In cases of severely misaligned bite, referral to an orthodontist may be indicated.
Remember that you do not necessarily have TMD just because you have some of the characteristic signs of TMD. Just because you may have a hesitation on opening or closing, you can't open very wide and your joints click occasionally doesn't mean you have TMD that needs to be treated. Some patients go through their entire lives with mild clicking or limited opening while functioning normally and without any complaints or deterioration. Dr. McArdle feels that unless you are in pain, your jaws lock, your teeth wear unusually, you need extensive restorative treatment or there are bony changes on the panoramic image of your joints, there is no need for TMD treatment. If you are in this situation, Dr. McArdle will monitor your situation closely at each of your routine oral examinations to check for any changes that may suggest some deterioration in them. If this occurs, proper treatment will be initiated at that time.
IF YOU BECOME AWARE OF ANY OF THE SIGNS OR SYMPTOMS OF TMD, NOTIFY DR. MCARDLE
IMMEDIATELY SO HE CAN EVALUATE THEM TO DETERMINE IF TREATMENT IS NECESSARY!