How the Chewing Muscles and Jaw Joints Work

The structures that make it possible to open and close the mouth are very specialized and work together when you chew, speak and swallow.  These structures include muscles and ligaments, as well as the bones and discs which make up the TM joints.

A number of muscles allow you to open and close your mouth.  They also control forward, backward and side-to-side movements of the lower jaw.  Both joints also are involved in these movements.  Each of these joints has a disc between the ball and socket.  This disc cushions the load while enabling the jaw to open widely and to move in combinations of hinge and gliding movements.  Any problem that prevents this complex system of muscles, ligaments, discs and bones from working together properly may result in a TM disorder. 

Causes of TM Disorders

When muscles and joints do not work properly, the muscles will often go into a spasm (cramp).  This spasm can become part of a cycle that results in tissue damage, pain, muscle tenderness and more spasm.

While some cases of TM disorder may have clear-cut causes such as trauma, arthritis, or severe stress, most are due to a combination of factors.  Discs often slip forward in the joint, leading to problems such as clicking, popping, or even getting "stuck" for a moment.  However, these often are minor problems, and in the absence of jaw pain they usually don't require treatment.

Oral habits such as clenching or grinding the teeth (bruxism) may develop as a response to stress, or as part of a sleep disorder.  You may not be aware of nighttime clenching or grinding, but you may catch yourself doing this during the day.  These habits can tire the muscles and cause them to go into spasm.  The spasm causes pain which in turn causes more spasm.  In time, persistent muscle problems may affect the joints themselves, and a complex cycle of pain and improper function will be set up.

It is important to note that while many of the above factors are believed to cause TM disorders, the exact causes of the disorders are unknown and sometimes it is not possible to determine the causes of the symptoms.

Signs and Symptoms of TM Disorders

TM disorders have many signs and symptoms.  Some of the most common ones include the following:

•  Pain in or around the ear, sometimes spreading to the face.
•  Tenderness of the jaw muscles.
•  Clicking or popping noise when one opens or closes the mouth.
•  Difficulty in opening one's mouth.
•  Jaws that "get stuck," "lock," or "go out."
•  Pain brought on by yawning, chewing or opening the mouth widely.
•  Certain types of headaches or neckaches.

Your dentist can recommend a course of treatment by taking a complete history, conducting a clinical examination and by taking appropriate X-rays, or perhaps other diagnostic tests.  To the extent that the causes of you TM disorder can be identified, proper diagnosis is an important step before treatment.  It can save time and money by ensuring that you receive the treatment appropriate for your particular problem.

Treatment of TM Disorders

Treatments for TM disorders vary, based on your individual diagnosis.  The dentist may recommend a treatment involving a series of phases.  This step-by-step plan is in your best interest because only minor corrective treatment may be needed.

If pain and other symptoms persist, a more involved treatment may be considered.  Although the specific therapy recommended for you may not be described below, your dentist may consider the following:

•  Trying to eliminate muscle spasm and pain by applying moist heat or prescribing medication such as muscle relaxants, analgesics or anti-inflammatory drugs.
•  Eliminating some of the harmful effects of clenching or grinding the teeth by wearing bite plates.
•  Teaching relaxation techniques to help control muscle tension in the jaw.  Your dentist may suggest training or counseling to help eliminate stress, tooth grinding or clenching. 
•  Finally, when the jaw joints are affected and other treatments have been unsuccessful, jaw joint surgery may be recommended.

Your dentist and other health professionals who provide treatment for TM disorders care about your health and comfort.  Discuss your concerns openly with them.  In many cases the pain, headaches and other symptoms associated with TM disorders can be successfully and readily treated.