Temporomandibular Joint Disor... Health Article

Definition

Temporomandibular joint (TMJ) disorder, also known as TMD, is the name given to a group of symptoms that cause pain in the facial muscles and dysfunction in the head, face, and jaw. TMD often has psychological as well as physical causes.

Description

TMD results from pressure on the facial nerves due to muscle tension, injury, or bone abnormalities. Some 70% of adults exhibit at least one sign of TMD, but only 5% seek treatment. Most sufferers are women between ages 20 and 50.

The TMJ connects the temporal bone with the condyle of the mandible anterior to the ear on each side of the skull. The jaw pivots on ligaments, tendons, and muscles to allow motion downward and laterally as well as forward. Anything that causes a change in shape or functioning of the TMJ can cause pain and other symptoms.

Causes

TMD has varied causes:

• Bruxism, or unconscious clenching or grinding of the teeth, is the most common cause of TMD. Bruxism occurs during periods of stress or during sleep. It results in muscle tension and soreness around the jaw joint and in the facial muscles.
• Misalignment of the teeth or displacement of the TMJ disc may contribute to TMD.
• Injury to the jaw or side of the head, either from a direct blow or from repeated and prolonged opening and closing (as in gum chewing), can result in a dislocation of the TMJ and subsequent TMD problems.
• Arthritis in different forms can lead to TMD. Traumatic arthritis from an injury, osteoarthritis, and rheumatoid arthritis are all possible causes.
• Hypermobility, a condition in which the ligaments of the TMJ are too loose, may allow the mandible to slip out of position and create TMD.
• Poor posture is another potential cause of TMD. When an individual carries his or her head too far forward and strains the neck muscles, TMD can result. In one research study in Texas, patients who were given posture training along with traditional treatment had greater improvement than those without posture training.
• Birth abnormalities are the least frequent cause of TMD, but can occur. In some cases, the condyle of the mandible is too large or too small.