More than 15% of Australian adults suffer from chronic facial pain, typically in or around the ear and jaw. The pain is often accompanied by clicking or popping noises when opening the mouth, or headaches and neck aches.
The temporomandibular joint (TMJ) connects the lower jaw, called the mandible, to the temporal bone at the side of the head. Because these joints are flexible, the jaw can move smoothly up and down and side to side, enabling us to talk, chew, and yawn. Muscles attached to, and surrounding the jaw joint, control its position and movement.
When we open our mouths, condyles (the rounded ends of the lower jaw), glide effortlessly along the joint socket of the temporal bone. A soft disc lies between the condyle and the temporal bone to ensure smooth motion. This disc absorbs shocks to the TMJ from all movements.
Temporomandibular (jaw) disorders, also called TMD or TMJ syndrome, are a general class of health problems associated with the jaw. TMD may occur when the jaw twists during opening, closing or side-motion movements. These movements affect the jaw joint and the muscles that control chewing. Although researchers do not yet know how many people have TMD, the disorders appear to affect twice as many women as men. People with TMD often clench or grind their teeth at night, which can tire the jaw muscles and lead to pain.
A dental exam and X-rays may identify the source of the pain. In some cases, the pain may be linked to a sinus problem, toothache, or an early stage of periodontal disease.
Other reasons are not so easily diagnosed. The pain could be related to the facial muscles, the jaw or TMJ in the front of the ear. Treatments for this pain may include stress reducing exercises, muscle relaxants, or wearing a mouth protector to prevent teeth grinding.
The majority of TMJ problems can be treated by resting the joint, taking a pain reliever without aspirin, and practicing stress management and relaxation techniques.
More severe cases may be treated with physical therapy, ice and hot packs, posture training, and splints.
Fortunately for most people, jaw joint or jaw muscle pain is usually not a sign of a more serious problem. Pain and discomfort from TMD is temporary and sporadic, and can come in waves or cycles. Only a small percentage of people with TMD pain develop significant, long-term symptoms.
Temporomandibular disorders fall into three main categories:
- Myofascial pain, the most common form of TMD, which is discomfort, or pain in the muscles that control jaw function and the neck and shoulder muscles
- Internal derangement of the joint, dislocated jaw or disc, or injury to the condyle
- Degenerative joint disease, such as osteoarthritis or rheumatoid arthritis in the jaw joint
Severe injury to the jaw or TMJ can lead to problems. Arthritis in the jaw joint may also follow an injury. Orthodontic treatment, such as braces and the use of headgear, has also been blamed for some forms of TMD, but studies now show that this is unlikely.
As long as the displaced disc causes no pain or problems with jaw movement, no treatment is needed.