Temporomandibular joint disorders - (TMJ)
Temporomandibular joint disorders are a variety of conditions that cause pain in the temporomandibular joint (TMJ). TMJ is the hinge joint on each side of your head where your lower jawbone (mandible) joins the temporal bone of your skull. Problems include popping sounds in the jaw, jaw pain, earaches, and other types of facial pain.
The bony surfaces of the TMJ are covered with cartilage and separated by a small disk, which prevents them from rubbing against each other. The muscles that enable you to open and close your mouth stabilize this joint.
The potential causes of tenderness and pain in your TMJ are many. They include wear and tear, arthritic inflammation, injury, stress, some dental appliances, and clenching or grinding your teeth. The pain associated with TMJ disorders can vary from minor to severe. The condition may be temporary or chronic.
However, a variety of approaches can provide relief, and you can take actions to counter the factors that may lead to TMJ pain.
Signs and symptoms
Signs and symptoms of TMJ disorders may include:
You may feel the pain or tenderness, even when you aren't moving your jaw. But in most cases, the pain or tenderness worsens when you move your jaw or chew.
A dull discomfort in your jaws and muscles on awakening in the morning or that gets progressively worse throughout the day may be the result of excessive grinding (bruxism) and jaw clenching. This condition is sometimes associated with a TMJ disorder.
Jaw clicking is common and doesn't always signal a problem. If there's no pain or limitation of movement associated with your jaw clicking, you probably don't have a TMJ disorder.
Tenderness and pain originating in the TMJ can stem from a variety of causes. Like other joints, the TMJ is susceptible to osteoarthritis, rheumatoid arthritis and other forms of inflammation.
Normally, the TMJ allows the jaw to open and close smoothly. The lower jaw has rounded ends called condyles that glide in and out of the joint socket when you talk, chew or yawn. There is also a disk between each condyle and the bone to absorb shock and keep the movement smooth.
If movement of your left and right TMJs aren't coordinated, pain and other symptoms can develop. The disk that separates your lower jaw from your skull can slip out of position or a condyle can become dislocated, either of which can cause pain or the inability to open your mouth or jaw fully. An improperly aligned bite can contribute to dislocation. Pain in the TMJ can also result from degeneration of or trauma to the joint, such as by a blow to your jaw.
Chronic tension and anxiety may cause you to grind your teeth (bruxism), often at night, or to maintain clenched jaws. This overuse of your TMJ and supporting muscles may cause pain.
Stress can be a factor in temporomandibular joint disorders. Chronic tension and anxiety may cause you to keep your jaws clenched, overusing the muscles attached to the temporal bone that stabilize the temporomandibular joint, leading to a TMJ disorder.
Stress can cause you to vigorously grind your teeth even when you're not eating. Vigorous and excessive grinding overuses the muscles of the temporomandibular joint region, which can cause pain. Many people are unaware they grind their teeth while they are sleeping.
Women are more likely to develop TMJ disorders than are men.
When to seek medical advice
If you have persistent pain or tenderness in your temporomandibular joint, if you have facial pain and experience clicking or grating when you chew or move your jaw, or if you can't open or close your jaw completely, seek medical attention. Your doctor, dentist, TMJ specialist, or oral and maxillofacial surgeon can discuss possible causes and treatments with you.
Screening and diagnosis
Your doctor, dentist, TMJ specialist, or oral and maxillofacial surgeon can discuss your signs and symptoms with you, how long you've experienced them, whether you've had an injury to your jaw, and whether you've had recent dental treatment. In addition, your doctor or dentist can listen to any sounds your jaw makes and observe the range of motion of your jaw.
Examining your bite can reveal abnormalities in the alignment of your teeth and in the movement of your jaw. Conditions such as a high filling, a tipped tooth, teeth displaced due to earlier loss of other teeth or certain inherited characteristics can cause misalignments and subsequent pain. Your dentist can also determine if you chronically grind your teeth by examining the wear patterns. Feeling the joint while you move it also may help your dentist diagnose the condition. Examination of the muscles that open and close the jaw can reveal a muscular component of the pain.
An X-ray or computerized tomography (CT) scan can evaluate the bony structures in your mouth. A magnetic resonance imaging (MRI) scan can provide an image of the disk and soft tissue to check for abnormalities.