What are temporomandibular disorders (TMD)?

Temporomandibular disorders (TMD) are disorders of the jaw muscles, temporomandibular joints, and the nerves linked to chronic facial pain. Any problem that prevents the complex system of muscles, bones, and joints from working together in harmony may result in temporomandibular disorder.

The temporomandibular joints (TMJ) are the 2 joints that connect your lower jaw to your skull. More specifically, they are the joints that slide and rotate in front of each ear. They include the lower jaw (mandible) and the temporal bone (the side and base of the skull). The TMJs are among the most complex joints in the body. These joints, along with several muscles, allow the mandible to move up and down, side to side, and forward and back. When the mandible and the joints are correctly aligned, smooth muscle actions can take place. These include chewing, talking, yawning, and swallowing. When these structures (muscles, ligaments, disk, jawbone, temporal bone) are not aligned, they don’t move well together. This may cause several problems to occur.

The National Institute of Dental and Craniofacial Research classifies TMD by the following:

• Myofascial pain. This is the most common form of TMD. It results in discomfort or pain in the connective tissue covering the muscles (fascia) and the muscles that control jaw, neck, and shoulder function.

• Internal derangement of the joint. This means a dislocated jaw or displaced disk. A disk is the cushion of cartilage between the head of the jawbone and the skull. Or it may mean an injury to the condyle. This is the rounded end of the jawbone that articulates with the temporal skull bone.

• Degenerative joint disease. This includes osteoarthritis or rheumatoid arthritis in the jaw joint.

You can have 1 or more of these conditions at the same time.

What causes TMD?

In many cases, the actual cause of this disorder may not be clear. Sometimes the main cause is too much strain on the jaw joints and the muscle group that controls chewing, swallowing, and speech. This strain may be due to bruxism. This is the habitual, involuntary clenching or grinding of the teeth. Injury to the jaw, the head, or the neck may also cause TMD. Arthritis and displacement of the jaw joint disks can also cause TMD pain. In other cases, another painful health condition, such as fibromyalgia or irritable bowel syndrome, may overlap with or make TMD pain worse. A recent study by the NIDCR identified clinical, psychological, sensory, genetic, and nervous system factors that may put a person at higher risk of developing chronic TMD.

What are the symptoms of TMD?

The following are the most common symptoms of TMD:

• Jaw discomfort or soreness (often most common in the morning or late afternoon)

• Headaches

• Pain spreading behind the eyes, in the face, shoulder, neck, or back

• Earaches or ringing in the ears (not caused by an infection of the inner ear canal)

• Clicking or popping of the jaw

• Locking of the jaw

• Limited mouth motions

• Clenching or grinding of the teeth

• Dizziness

• Teeth sensitivity without an oral health disease

• Numbness or tingling feeling in the fingers

• A change in the way the upper and lower teeth fit together

The symptoms of TMD may look like other conditions or health problems. See a dentist or your healthcare provider for a diagnosis.

How is TMD diagnosed?

A variety of methods are used to diagnose TMD. These include:

• Health history. Your healthcare provider will ask if you have a past history of facial or jaw pain when you chew, bite, or open your mouth. Your provider will ask if you have had cracking, popping, or noise when opening or closing your mouth.

• Physical exam. Your provider will check if you have facial or jaw pain when moving your jaw or can’t open your mouth wide. They will also check for TMJ noises when you open or close your mouth.

• Imaging tests. X-rays, CT scans, and MRIs may be used to clarify a diagnosis.

How is TMD treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is and what the cause is.

Treatment may include:

• Resting the temporomandibular joint (TMJ)

• Medicine or pain relievers

• Relaxation methods and stress management

• Behavior changes (to reduce or stop teeth clenching)

• Physical therapy

• An orthopedic appliance or mouthguard worn in the mouth (to reduce teeth grinding)

• Posture training

• Diet changes, such as eating soft foods (to rest the jaw muscles)

• Ice and hot packs

• Surgery

TMD symptoms can come back during times of stress. It is helpful to be aware of what triggers your symptoms so you can do things to prevent it from happening again. See your dentist on a regular basis so your TMD can be checked.

Key points about temporomandibular disorders

• Temporomandibular disorders (TMD) are disorders of the jaw muscles, temporomandibular joints, and the nerves linked to chronic facial pain.

• It may be caused by too much strain on the jaw joints and the muscle group that controls chewing, swallowing, and speech. This may be due to teeth grinding, injury to the jaw, head, or neck, or arthritis.

• Symptoms may include jaw pain, headaches, earaches, limited mouth motions, and jaw clicking, popping, or locking. There may also be pain in the face, shoulder, neck, or back.

• Treatment may include resting the temporomandibular joint, physical therapy, medicine, behavior changes, or an orthopedic appliance or mouthguard.

• TMD symptoms can come back during times of stress. It helps to be aware of what triggers your symptoms so you can prevent a recurrence.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new directions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions.