Temporomandibular disorders (TMD) involves the two joints that link the lower jaw to the skull. These joints let the mouth open and close. They are in front of your ears.

There are three types of TMD:

  • Myofascial pain of the muscles that control jaw function
  • Joint derangement, such as a displaced disc, dislocated jaw, or injury to the bone
  • Arthritis of the temporomandibular joint
Adult Skull Showing Temporomandibular Joint
Adult Skull Showing TMJ and Muscles
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You may have TMD if:

  • The temporomandibular joints (TMJ) are often swollen and sore.
  • The muscles that work the joints spasm often.
  • The disc that rests between the joint and the skull is worn out or out of place.
  • You have problems moving your jaw.
  • Your bite is off or not in line.
  • You have clicking in when you move your jaw.

The exact cause of TMD is not known. Some people have had accidents or injuries of the jaw, but many others have not. Some causes may be:

  • Grinding the teeth or clenching the jaw because of stress
  • Arthritis of the joint
  • Past injury or trauma to the joint
  • Facial bone defects
  • A bit that is off or not in line

Enlargement of TMJ With Jaw Open
Enlargement of TMJ with Open Jaw
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TMD symptoms may originate within the joint itself or from the muscles that surround the joint. The treatment of these 2 variants of TMD may differ.

What are the risk factors for TMD?What are the symptoms of TMD?How is TMD diagnosed?What are the treatments for TMD?Are there screening tests for TMD?How can I reduce my risk of TMD?What questions should I ask my doctor?What is it like to live with TMD?Where can I get more information about TMD?

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