You may have heard about “TMD” — temporomandibular (jaw) disorders, also called “TMJ syndrome.” TMD is not just one disorder, but a group of conditions, often painful, that affect the jaw joint (temporomandibular joint, or TMJ) and the muscles that control chewing.
What is the Temporomandibular Joint?
The temporomandibular joint connects the lower jaw, called the mandible, to the temporal bone at the side of the head. If you place your fingers just in front of your ears and open your mouth, you can feel the joint on each side of your 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, the rounded ends of the lower jaw, called condyles, glide along with the joint socket of the temporal bone. The condyles slide back to their original position when we close our mouths. To keep this motion smooth, a soft disc lies between the condyle and the temporal bone. This disc absorbs shocks to the TMJ from chewing and other movements.
What are Temporomandibular Disorders?
Today, researchers generally agree that 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, meaning a dislocated jaw or displaced disc, or injury to the condyle
Degenerative joint disease, such as osteoarthritis or rheumatoid arthritis in the jaw joint
A person may have one or more of these conditions at the same time.
We know that severe injury to the jaw or temporomandibular joint can cause TMD. A heavy blow, for example, can fracture the bones of the joint or damage the disc, disrupting the smooth motion of the jaw and causing pain or locking. Arthritis in the jaw joint may also result from injury. Other causes of TMD are less clear. Some suggest, for example, that a bad bite (malocclusion) can trigger TMD, but recent research disputes that view. 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.
Some experts suggest that stress, either mental or physical, may cause or aggravate TMD. People with TMD often clench or grind their teeth at night, which can tire the jaw muscles and lead to pain.
TMD Signs and Symptoms
A variety of symptoms may be linked to TMD. Pain, particularly in the chewing muscles and/or jaw joint, is the most common symptom. Other likely symptoms include:
- Limited movement or locking of the jaw
- Radiating pain in the face, neck or shoulders
- Painful clicking, popping or grating sounds in the jaw joint when opening or closing the mouth
- A sudden, major change in the way the upper and lower teeth fit together
Symptoms such as headaches, earaches, dizziness and hearing problems may sometimes be related to TMD.
The best way to get a diagnosis is to be being with an oral examination. The examination includes feeling the jaw joints and chewing muscles for pain or tenderness; listening for clicking, popping or grating sounds during jaw movement; and examining for limited motion or locking of the jaw while opening or closing the mouth. In most cases, this evaluation provides enough information to locate the pain or jaw problem, to make a diagnosis, and to start treatment to relieve pain or jaw locking.
Most TMD problems are temporary and do not get worse, simple treatment is all that is usually needed to relieve discomfort. Self-care practices, for example, eating soft foods, applying heat or ice packs, and avoiding extreme jaw movements (such as wide yawning, loud singing and gum chewing) are useful in easing TMD symptoms. Learning special techniques for relaxing and reducing stress may also help patients deal with the pain that often comes with TMD problems.
Other conservative, reversible treatments include physical therapy, which focuses on gentle muscle stretching and relaxing exercises, chiropractic therapy, and short-term use of muscle-relaxing and anti-inflammatory drugs.
The health care provider may recommend an oral appliance, also called a splint or nightguard, which is a plastic guard that fits over the upper or lower teeth. The splint can help reduce clenching or grinding, which eases muscle tension.
There are other types of TMD treatment, such as surgery or injections, that invade the tissues. Some involve injecting pain-relieving medications into painful muscle sites, often called “trigger points.”
Surgical treatments are often irreversible and should be carefully considered by yourself and your doctor. When such treatment is necessary, be sure to have the doctor explain to you, in words you can understand, the reason for the treatment, the risks involved, and other types of treatment that may be available.