Definition

Temporomandibular disorder (TMD) is a painful condition. It involves the joint that opens and closes the mouth. The temporomandibular joints are the small joints in front of each ear. They attach the lower jaw (mandible) to the skull. The disorder may affect the jaw joint or the muscles surrounding it.

The Temporomandibular Joint

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Causes

The exact cause of TMD syndrome is often unclear. Possible causes include:

  • Excess tension in the jaw muscles
  • Faulty alignment between the upper and lower teeth and jaws
  • Disturbed movement of the jaw joint
  • Displacement or abnormal position of the jaw joint or cartilage disc inside the jaw joint
  • Arthritis or similar inflammatory process in the joint
  • Excess or limited motion of the joint
  • Injury of the jaw or face

Risk Factors

Factors that increase your chance of TMD include:

  • Sex: female
  • Age: 30 to 50 years old
  • Clenching or grinding of teeth
  • Poorly fitting dentures or crowns
  • Fibromyalgia
  • Stress
  • Arthritis

Symptoms

Symptoms include:

  • Pain in the temporomandibular joint, jaw, or face
  • Pain may be worse with chewing, yawning, or opening the mouth
  • Clicking, popping, or grating sounds with movement of the jaw
  • A sensation of the jaw catching or locking briefly, while attempting to open or close the mouth, or while chewing
  • Difficulty opening the mouth completely
  • A bite that feels off, uncomfortable, or as though it is frequently changing
  • Swelling in the affected side of the face or mouth
  • Painful muscle spasm in the area of the temporomandibular joint
  • Headache
  • Earache
  • Neck, back, and/or shoulder pain

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. The physical exam may include:

  • Range of motion tests
  • Listening for sounds of popping or clicking in the temporomandibular joints
  • Visual inspection of your teeth, temporomandibular joints, and muscles of your face and head
  • Palpation of the joints and the muscles of the face and head

Other tests may include:

  • X-rays —plain x-rays or panoramic dental x-rays of the jaw and jaw joint
  • Arthrography—jaw movements videotaped with x-rays taken after dye is injected into the joint
  • MRI scan —a test that uses magnetic waves to create detailed images of the joint

Treatment

Treatment may include:

Lifestyle Measures

  • Rest the jaw with a soft diet
  • Restrict movement with smaller bites
  • Apply warm packs for pain relief
  • Cognitive behavior therapy may help some learn to avoid clenching and grinding their teeth

Medications

The most commonly used medicines include:

  • Acetaminophen
  • Nonsteroidal anti-inflammatory drugs
  • Muscle relaxants
  • Low-dose antidepressants

Some medication may be injected into the jaw such as:

  • Pain relieving medicine (eg, cortisone or lidocaine)
  • Botulinum toxin (Botox)—may offer temporary relief if pain or clicking are major symptoms

Physical Therapy

To help reduce pain and allow muscles to relax:

  • Gentle massage or stretching exercises
  • Transcutaneous electrical nerve stimulation (TENS)

Stress Reduction

Dental Procedures

A splint or mouth guard can be made to relax your jaw muscles. This will prevent clenching and grinding of your teeth. The guard is usually worn at night. Correction of bite abnormalities by a dentist or orthodontist is sometimes needed.

Surgical Procedures

Surgical correction is a last resort. Many of the available procedures have not been well-studied for their effectiveness.

Prevention

There are no guidelines for preventing TMD. If you have TMD, the following may help prevent symptoms:

  • Ask your dentist if you need a night guard for grinding and clenching of the teeth.
  • Try to limit jaw movements. Learn to relax your jaw. Block a yawn by putting your fist under your chin.
  • Avoid extensive movements of the jaw.
  • Don't chew gum.
  • Learn relaxation techniques. Develop effective ways to cope with stress.