|Temporomandibular Disorder (TMD)|
Temporomandibular disorder (TMD) is a common ailment of the jaw joint. It is estimated that more than 10 million Americans have TMD symptoms at one time or another. A majority of these people are women between the ages of 20 and 40.
The good news is that for most TMD sufferers, symptoms usually do not lead to a serious, long-term problem. In fact, with or without treatment, most people eventually get better. Unfortunately, some people have severe pain and discomfort that lasts for many years.
TMD is not just one specific problem. It is a group of conditions that affect the jaw joint, also known as the temporomandibular joint or TMJ, and/or the muscles that control chewing and jaw movement.
The TMJ is like a ball and socket. When you open your mouth, the ball, or condyle, moves along the joint socket, or glenoid fossa. When you close your mouth, the ball slides smoothly back in place. A soft cushion, or disk, lies between the ball and socket. The cushion prevents these parts from rubbing and absorbs shocks from movements such as chewing. Holding all this together are muscles that stretch from the top of the skull to the lower jaw. Usually the muscles that help close the jaw are the ones affected in TMD.
The jaw joint allows you to open and close your mouth and move your jaw from side to side and backward and forward. As a result, we can talk, yawn, chew and swallow. You can feel these two joints by placing fingers on each side of your face in front of your ears. Now open and close your mouth. You should feel the condyle moving in and out of the socket.
Today, most experts agree that TMD falls into three categories:
- Problems that affect the muscles in the jaw and neck
- Problems that affect the bones and cartilage within the joint
- TMD that falls into both categories
Some people have TMD that falls into more than one category.
TMD can cause many different types of symptoms. In fact, it often causes symptoms very similar to other diseases and conditions. That's why it can be so difficult for doctors to diagnose.
The most common symptom of TMD is pain or discomfort in the jaw joint or chewing muscles. Other symptoms may include:
- Popping, clicking or grating noises when the jaw opens and closes
- An inability to open the mouth wide
- Pain in the face, neck and shoulders
- A tired feeling in the face
- A sudden uncomfortable bite, as if the upper and lower teeth don't fit together the right way
- Swelling on the side of the face
Some people also have earaches, toothaches, headaches, ringing in the ears, dizziness or hearing problems.
Experts are unsure about what causes TMD. However, many think that symptoms can be the result of:
- Injury to the jaw, chin or TMJ as a result of a car accident, fight or fall. It is also possible to injure the jaw by opening the mouth too wide if you already have a TMJ condition.
- Grinding or clenching the teeth, which puts a lot of pressure on the TMJ
- Dislocation of the soft cushion or disk between the ball and socket
- Arthritis, such as osteoarthritis or rheumatoid arthritis
- Stress, which causes a person to tighten facial and jaw muscles or clench his or her teeth
In some cases, dentists are unable to determine the exact cause of a person's TMD.
The symptoms of TMD often resemble or mimic other conditions and diseases, including migraine headaches and neuralgia. For this reason, it is difficult to diagnose. There is also no test that gives a definitive answer.
If your dentist suspects that you have TMD, he or she will review your medical history, including:
- Your symptoms
- When your symptoms started
- Whether the symptoms are constant or come and go
- Whether you have pain when you wake up in the morning
- Whether the pain gets better or worse during the day
- How the symptoms affect your life
- Whether you have other conditions or diseases such as arthritis
- Whether you take medicine for other conditions or diseases
- Whether there have been recent changes in your life that are causing you stress
Your doctor also will do a physical examination, and will:
- Feel your jaw joints and facial muscles
- Listen for popping or clicking noises as you open and close your mouth
- Examine how far you can open your mouth
- Look at your teeth for signs of grinding or clenching, also called bruxism
Usually this is enough information to identify the problem, make a diagnosis and determine the best form of treatment. Your dentist also may take a panoramic X-ray to evaluate the bones. This also allows the dentist to be sure that other problems aren't causing your symptoms.
In some cases, more testing is needed. Your dentist may request magnetic resonance imaging (MRI). This special test provides an image of the TMJ disk and its relation to the ball and socket. It also can evaluate the health of the bone in the joint. In rare instances, other imaging tests may be needed.