The Temporo-Mandibular Joint (TMJ) is the joint where the mandible, or lower jaw, joins the temporal bone of the skull immediately in front of the ear on each side of your head. A small disc of cartilage separates the bones, so that the mandible may slide easily, especially as it moves each time you chew, talk or swallow. It is one of the most frequently used joints in the body as well as one of the most complex.
You can locate this joint by putting your finger on the triangular structure in front of your ear. Then move your finger just slightly forward and press firmly while you open and close your jaw. The motion you feel is the TMJ. You can also feel the joint motion in your ear canal. These maneuvers can cause considerable discomfort to a patient who is having TMJ trouble, and physicians use these maneuvers with patients for diagnosis.
How Does TMJ Work?
When you bite down hard, you put force on the object between your teeth and on the joint. In terms of physics, the jaw is the lever and the TMJ is the fulcrum. More force is applied (per square foot) to the joint surface than to whatever is between your teeth. To accommodate such forces and to prevent too much wear and tear, the cartilage between the mandible and skull normally provides a smooth surface, over which the joint can freely slide with minimal friction.
This distributes the forces of chewing over a wider surface in the joint space and minimize the risk of injury. In addition, several muscles contribute to opening and closing the jaw and aid in the function of the TMJ.
How Does TMJ Dysfunction Feel?
- Ear pain
- Sore jaw muscles
- Temple/cheek pain
- Jaw popping/clicking
- Locking of the jaw
- Difficulty in opening the mouth fully
- Frequent head/neck aches
The pain associated with TMJ dysfunction may be sharp and searing, occurring each time you swallow, yawn, talk, or chew, or it may be dull and constant. It hurts over the joint, immediately in front of the ear, but pain can also radiate elsewhere. It often causes spasms in the adjacent muscles that are attached to the bones of the skull, face, and jaw. However, pain can also be felt at the side of the head, cheek, lower jaw, and teeth.
Patients should also be aware that a very common focus of pain is in the ear. Many patients come to the doctor convinced their pain is from an ear infection. When the earache is not associated with a hearing loss and the eardrum looks normal, the doctor will consider the possibility that the pain comes from TMJ dysfunction.
In addition to pain, TMJ dysfunction can cause popping, clicking, or grinding sounds when the jaw is opened widely, or the jaw locks when wide open. At the other extreme, TMJ dysfunction can prevent the jaws from fully opening. Some also experience ringing in their ears from TMJ issues.
How Can Things Go Wrong with TMJ?
In most patients, pain associated with the TMJ is a result of displacement of the cartilage disc that causes pressure and stretching of the associated sensory nerves. The popping or clicking occurs when the disk snaps into place when the jaw moves. In addition, the chewing muscles may spasm, not function efficiently, and cause pain and tenderness.
Both major and minor trauma to the jaw can significantly contribute to the development of TMJ problems. If you habitually clench, grit, or grind your teeth, you increase the wear on the cartilage lining of the joint, and it doesn't have proper time to recover. Many are unaware that they grind their teeth, unless someone tells them of the habit.
Chewing gum constantly can cause similar problems. Stress and other psychological factors have also been implicated as contributory factors to TMJ dysfunction. Other causes include teeth that do not fit together properly (improper bite), malpositioned jaws, and arthritis. In certain cases, chronic malposition of the cartilage disc and persistent wear in the cartilage lining of the joint space can cause further damage.
What Can Be Done for TMJ?
Because TMJ symptoms often develop in the head and neck, otolaryngologists are appropriately qualified to diagnose TMJ problems. Proper diagnosis of TMJ begins with a detailed history and physical, including careful assessment of the teeth occlusion and function of the jaw joints and muscles. If the doctor diagnoses your case early, it will probably respond to simple self-remedies:
- Rest the muscles and joints by eating soft foods
- Do not chew gum
- Avoid clenching or tensing the jaw
- Relax muscles with moist heat (30 minutes at least twice daily)
In cases of joint injury, ice packs applied soon after the injury can help reduce swelling. Relaxation techniques and stress reduction, patient education, non-steroidal anti-inflammatory drugs, muscle relaxants or other medications may be recommended by your physician.
Other therapies may include fabrication of an occlusal splint to prevent wear and tear on the joint. Improving the alignment of the upper and lower teeth and surgical options are available for advanced cases. After diagnosis, your otolaryngologist may suggest further consultation with your dentist and oral surgeon to facilitate effective management of TMJ dysfunction.
Do not hesitate to contact your physician if you believe you are suffering from pain that may be associated with TMJ dysfunction.
The information provided above is for general use only, and medical decisions should not be made without consulting a physician. The information is provided by The American Academy of Otolaryngology Head & Neck Surgery Foundation.
