Temporomandibular joint syndrome (TMJ) is a group of disorders that affect the jaw joint and the muscles that allow us to chew. The TMJ is a ball- and -socket joint on each side of your head, in front of your ear, where the lower jaw and skull meet. The lower jaw has rounded ends (condyles) which glide in and out of the joint socket when you chew, talk or yawn. Cartilage covers the surfaces of the condyle and the socket of the temporal bone. Between the surfaces is a small disk which acts as a shock absorber to keep the movements smooth. This joint is stabilized by the muscles that allow you to open and close your mouth. There are also ligaments that stabilize this joint. Besides being important for talking, chewing and yawning the TMJ's, along with the muscles and ligaments that stabilize it, play an important role in swallowing and making facial expressions.
Approximately 25% of the population, in the United States, experience symptoms of TMJ syndrome in their lives. The female to male ratio is approximately 4:1. For some patients, symptoms are resolved within weeks or months. For other patients, chronic symptoms may persist for years despite therapy. The greatest incidents are between the ages of 20 and 40 years. TMJ disorders rarely occur in the pediatric population. Seek medical attention if you experience popping or clicking when moving your jaw, persistent pain in your jaw or difficulty closing your jaw completely.
Signs and Symptoms
The most common symptom is pain at the jaw joint where the jaw meets the skull, just in front of the ear on each side of the face. Signs and symptoms may also include
- jaw pain or tenderness;
- radiating pain to the ear or around the ear;
- pain and or difficulty with chewing;
- facial pain;
- neck, mid back and shoulder pain;
- locking of the jaw;
- an uneven or uncomfortable bite;
- limited jaw opening;
- facial swelling; and
- rheumatoid arthritis;
- degeneration of the joint;
- trauma in the past such as a severe blow to the jaw;
- stress or anxiety;
- poor posture of the head, neck, and shoulders;
- poor fitting dentures;
- repetitive chewing of gum or ice;
- repetitive clenching of the jaw or grinding of the teeth (related to stress and anxiety and may occur when sleeping);
- mal-alignment of the teeth and other dental abnormalities;
- hereditary conditions;
- hypermobile TMJs; and
- whiplash injuries.
TMJ disorder can be diagnosed by your dentist, oral and maxillofacial surgeon, or doctor. Doctors include your primary health provider, an ear, nose, and throat doctor (ENT doctor) or pain management specialist. They will perform a history and physical examination. These may include
- inquiring about the length of time of your symptoms, previous history of injuries to your jaw and recent history of dental treatment;
- inquiring about recent or old stressors and possible causes of anxiety;
- performing a dental examination;
- measuring the range of motion of your jaw;
- examining the alignment of your jaws;
- palpating or pressing on or around your jaw to localize areas of discomfort;
- listening for clicking or popping when you open and close your mouth;
- pressing or palpating to search for muscle spasms in your cheek and head; and
- magnetic resonance (MRI) scan of your jaw to examine soft tissues such as cartilage and disks;
- X-rays of the jaw area and mouth;
- computerized tomography(CT) scan of your jaw and mouth;
- complete blood count (CBC) if an infection is suspected;
- uric acid blood test if gout is suspected;
- rheumatoid factor blood test if rheumatoid arthritis is suspected;
- erythrocyte sedimentation rate blood test if temporal arteritis is suspected; and
- calcium, phosphate or alkaline phosphatase blood test if bone disease is suspected.
Occasionally, the symptoms of a TMJ disorder will resolve without treatment. These conservative treatments may be recommended by your healthcare provider:
- heating pad set at low for 15 minutes, 4 to 10 times a day;
- applying ice, with a barrier, to your jaw for 15 minutes, 4 to 10 times a day;
- avoiding repetitive movements of your jaw such as chewing gum or ice, and avoiding loud singing;
- altering your diet by eating only soft food and cutting your food into small pieces;
- not clenching your jaw or grinding your teeth (a bite block may be recommended to be worn at night);
- exercises to stretch your jaw muscles and massage your jaw muscles;
- exercises to improve the posture of your head, neck, and shoulders (holding the head forward for long periods can strain the muscles of the face and neck leading to "trigger points," localized areas of contracted muscles);
- aspirin or other non-steroidal anti-inflammatory drugs to decrease inflammation and pain (only taken with meals and avoided in asthma, peptic ulcer disease, kidney disease or bleeding disorders);
- psychotherapy including biofeedback to learn stress and anxiety reducing techniques;
- exercising regularly to decrease stress, decrease anxiety and improve your ability to handle pain;
- bite plate or splint if your TMJ is misaligned;
- mouth guard to help prevent grinding and excessive wear of your teeth;
- muscle relaxant medications for a short period;
- corticosteroid injection into the joint space;
- replacing missing teeth, fillings or crowns if an imbalance of the biting surfaces of your teeth is contributing to your TMJ disorder;
- physical therapy;
- ultrasound therapy to provide deep heat to the area of tenderness;
- massaging the masseter muscles on each side of your jaw by placing your thumb inside your mouth and squeezing the muscle of your cheek with your fingers (use your index finger to check for tender muscles in your cheek, behind your teeth and massage them).
- cold laser therapy;
- TENS; and
- techniques to treat or prevent insomnia.
Occasionally, your dentist may recommend orthodontics to help realign your teeth. Reconstructive surgery of the jaw is a rare treatment and a second opinion should be obtained if this procedure is recommended. Unfortunately, many studies have shown that the results are often worse after reconstructive surgery. Some health care providers perform arthroscopy of the joint. As with reconstructive surgery, a second opinion should be sought.
Jose Veliz MD is the medical director of Palomar Spine & Pain, in Escondido, CA (North San Diego County).