TMJ disorders include a variety of conditions that cause tenderness and pain in the temporomandibular joint (TMJ). Your TMJ is the ball-and-socket joint on each side of your head where your lower jawbone (mandible) joins the temporal bone of your skull.
The lower jaw has rounded ends (condyles) that glide in and out of the joint socket when you talk, chew or yawn. The surfaces of the condyle and the socket of the temporal bone are covered with cartilage and separated by a small disk, which absorbs shock and keeps the movement smooth. The muscles that enable you to open and close your mouth stabilize this joint.
Between 5 percent and 15 percent of people in the United States experience pain associated with TMJ disorders, according to the National Institute of Dental and Craniofacial Research (NIDCR), part of the National Institutes of Health. Women are more likely than men to develop TMJ disorders.
In most cases, pain and discomfort associated with TMJ disorders can be alleviated with self-managed care or nonsurgical treatments, but more severe cases may need to be treated with dental or surgical interventions.
The cause of some TMJ disorders can be traced to trauma from a severe blow to the jaw, degeneration of the joint, osteoarthritis, rheumatoid arthritis or other forms of inflammation.
The causes of many cases of TMJ disorders, however, aren't always clear. Some experts believe that responses to stress or anxiety may be a primary or contributing causal factor.
If you frequently clench your jaw when you're stressed, irritated or concentrating, the muscles of the TMJ are kept in a contracted position — not unlike the discomfort you would probably feel if you flexed your biceps all day. Similarly, you may respond to tension or anxiety by grinding your teeth (bruxism). You may even clench your jaw or grind your teeth in your sleep without realizing it.
Other habits that overwork the jaw muscles, such as chewing on a pen or chewing gum, may exacerbate the pain of TMJ disorders.
Poor posture of the head, neck and shoulders — such as pushing your head forward or slouching while working at a computer — may put strain on the muscular and skeletal systems that are closely related to the jaw muscles and joints.
NIDCR is conducting a large-scale study to assess early stages of TMJ disorders and to identify biological or genetic factors that may contribute to pain sensitivity.
When to seek medical advice :
If you have persistent pain or tenderness in your TMJ, 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 or a TMJ specialist can discuss possible causes and treatments of TMJ disorders with you.
Signs and symptoms of TMJ disorders may include :
- Pain or tenderness of your jaw
- Aching pain in and around your ear
- Difficulty chewing or discomfort while chewing
- Aching facial pain
- A clicking sound or grating sensation when opening your mouth or chewing
- Locking of the joint, making it difficult to open or close your mouth
- Uncomfortable bite
- An uneven bite, because one or more teeth are making premature contact
You may feel 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.
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.
Your doctor, dentist, oral and maxillofacial surgeon, or TMJ specialist can discuss your signs and symptoms with you. An exam may include the following issues :
- Conducting a medical history, including questions about how long you've experienced pain, whether you've had an injury to your jaw, and whether you've had recent dental treatment
- Listening to and feeling your jaw when you open and close your mouth
- Observing the range of motion in your jaw
- Examining your bite to check for abnormalities in the alignment of the jaws
- Checking for conditions — such as a high filling, a tipped tooth, teeth displaced due to earlier loss of other teeth or certain inherited characteristics — that can cause misalignment of your jaw
- Examining your teeth for wear patterns that would indicate chronic grinding
- Pressing on areas around your jaw to identify sites of pain or discomfort
- Asking questions about whether you're experiencing stress or anxiety and how you're coping
Your doctor may also order an X-ray or computerized tomography (CT) scan to assess the condition of the bony structures in your mouth or a magnetic resonance imaging (MRI) scan, which reveals such soft tissues as cartilage and disks.
Conservative, nonsurgical treatments
In some cases, the symptoms of a TMJ disorder may go away without treatment. If they persist, your doctor or dentist will most likely recommend one or more conservative, nonsurgical treatments or behavioral interventions to alleviate pain, to correct dental problems that contribute to the disorder, or to change habits that exacerbate symptoms. Your doctor or dentist may suggest the following treatments or interventions :
- Breaking bad tension-related habits. Your doctor will probably ask you to be aware of daytime habits, such as clenching your jaw, grinding your teeth, or chewing on your lip or on objects. These habits should be replaced with good jaw "posture" — keeping the jaw muscles relaxed with the teeth slightly apart, the tongue lightly touching the roof of your mouth and resting directly behind your upper teeth.
- Avoiding overuse of jaw muscles. Your doctor or dentist will probably ask you to change diet choices or behaviors that overwork or strain your jaw muscles. Eating soft foods, cutting food into small pieces, avoiding sticky or chewy food, and avoiding gum will minimize muscle use and may help alleviate pain. When yawning, avoid opening your mouth too wide.
- Stretching and massage. Your doctor or dentist may show you how to do exercises that stretch your jaw muscles and how to massage the muscles yourself. He or she may also show you exercises to improve your head, neck and shoulder posture.
- Heat or cold. Applying warm, moist heat or ice to the side of your face may help you relax your muscles or alleviate pain.
- Anti-inflammatory medications. To reduce inflammation and lessen pain, your doctor or dentist may advise taking aspirin or another nonsteroidal anti-inflammatory drug, such as ibuprofen (Advil, Motrin, others).
- Biteplate. If your TMJ is misaligned, your dentist may recommend a plastic biteplate (splint), worn over your teeth, to help align your upper and lower jaws. A biteplate may also reduce pressure in the joint structure.
- Night guard appliance. If you grind your teeth in your sleep, a night guard appliance, which is a soft or firm device inserted over your teeth, can help prevent grinding and excessive wear of your teeth.
- Cognitive-behavioral therapy. If your symptoms of TMJ disorder are made worse by poorly managed stress or anxiety, your doctor or dentist may refer you to a psychotherapist with experience in cognitive-behavioral therapy. This approach includes interventions to help you be aware of and change behaviors, learn relaxations techniques, manage stress, and change unproductive or harmful thinking habits.
If nonsurgical treatments or interventions don't alleviate the pain or discomfort of TMJ disorder, your doctor or dentist may recommend one of the following treatments.
- Corrective dental treatment. Your dentist may improve your bite by balancing the biting surfaces of your teeth, replacing missing teeth, or replacing needed fillings or crowns.
- Corticosteroid drugs. For significant pain and joint inflammation, corticosteroid drugs injected into the joint space may provide relief.
- Arthrocentesis. This procedure involves insertion of a needle into the joint so that fluid can be irrigated through the joint to remove debris and inflammatory byproducts.
- Surgery. If the other approaches don't work, your doctor or dentist may refer you to an oral and maxillofacial surgeon. Surgery to repair or remove the disk between your mandible and temporal bone may be beneficial. When advanced osteoarthritis is present, a partial or total joint replacement may be recommended and beneficial to remove bone-on-bone contact and improve joint mechanics and motion.