Temporomandibular disorders (TMD) involves the two joints that attach the lower jaw (mandible) to the skull. These two joints allow the mouth to open and close, and are located directly in front of your ears.

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 chronically inflamed and sore.
  • The muscles that work the temporomandibular joints are regularly in spasm.
  • The cushioning disc that should rest between the temporomandibular joint and the skull becomes worn out or displaced.
  • You have limited movement of your mandible.
  • You have clicking in the TMJ during motion.
  • Researchers do not exactly know what causes TMD. Some people have had accidents or injuries involving their jaw, but many others have had no such incident. Some of the possible causes include:

        
  • Grinding the teeth or clenching the jaw in response to stress, known as bruxism
  • Arthritis of the temporomandibular joint
  • History of injury or trauma to the joint
  • Facial bone defects
  • Misalignments of the jaw or of the bite
  • 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 two variants of TMD may differ.