Temporo Mandibular Joint - Enabling Jaw Movements, Structure and Conditions
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Temporo Mandibular Joint: Enabling Jaw Movements

Dr.Surya Rao Poodipeddi profile Authored by Dr.Surya Rao Poodipeddi on 2 May 2014 - 12:13.

Most of us might not have even heard the name of this joint, but all of us use it hundreds of times every day. We are speaking of a very important joint considered more busy than any other joint in the human body even while we are resting, a joint called Temporo Mandibular Joint (TMJ).

TMJ location: The temporo-mandibular joint can be located very easily. Put your finger over a triangular structure in front of the ear which is known as tragus. Just move your finger slightly forwards pressing it firmly while you open your jaw all the way and shut it when you can feel the movements of the joint .The motion you feel is due to the movements of the TMJ.

Structure: One of the four pairs of bones in the human skull is known as temporal bone (one on each side).The face has an L shaped bone called the mandible which is otherwise known as the lower jaw. The point where the mandible joins the temporal bone immediately in front of the ear on each side of the head is what constitutes the temporo-mandibular joint.

Like in the case of a knee joint a small disc of the cartilage separates the bones to enable the mandible to slide easily. Each time we chew food, talk, and swallow we move the temporo-mandibular joint. On an average we swallow once every three minutes.

We also move the TMJ when we yawn, laugh, frown, cough and shout loudly, besides several other activities involving the opening of the joint.  It is, therefore, one of the most frequently used of all joints of the body and one of the most complex too.

These oft repeated activities also explain why the TMJ is subjected to lot of pressure on the joint making it a victim for most of the problems affecting the joint.

Almost all the conditions affecting the temporo-mandibular joint present with one or more of the following signs and symptoms:

  • Pain in and around the ear is the commonest symptom which often spreads to the face.
  • The muscles of the jaw are tender when touched.
  • A distinctly audible clicking or popping noise when an attempt is made to open or close the mouth. In severe cases, the victim avoids opening the mouth because of intense pain.
  • Even when one tries to open the mouth it becomes difficult to do so.
  • In some cases the victim finds that the jaw is locked like in cases of tetanus when we term it as lock jaw. Sometimes it might get stuck or even go out.
  • Opening the mouth, attempting to yawn or trying to chew triggers the onset of pain.
  • One may notice certain types of headaches or pain in the neck.

Any problem in the TMJ needs a dentist’s attention who will conduct a series of diagnostic tests which includes a thorough medical history, clinical examination, X-ray and casts of your teeth.

Sometimes the dentist himself may refer you to another dentist with an additional specialization. If he suspects other problems as the cause of your distress, you may be referred to a physician. Though it involves considerable time and expenditure it is absolutely necessary to pinpoint the cause of your distress so that it can be treated successfully.

Several structures  like muscles, ligaments, bones and joints are involved in making it possible for the mouth to open to accomplish the act of chewing, speaking and swallowing all of which may pose different types of problems depending on what structure is affected. Therefore, a thorough evaluation becomes necessary for proper diagnosis.

Although accidents such as injuries to the jaw, head or neck, or diseases such as arthritis, may result in some TMJ problems, factors relating to the teeth and bite are also believed to be common causes of TMJ disorders.

These factors include:

  • Oral habits like clenching or grinding the teeth. These habits can tire the muscles and lead them to spasm which causes pain which in turn causes more spasm and the vicious circle continues. The end result of the cycle “spasm-pain-spasm” is what constitutes a TMJ disorder.
  •  Problems in the teeth like improper alignment could be the cause for stress on the muscles of chewing once again leading to spasm-pain-spasm cycle.
  • Oral habits and problems with the bite often work together leading to severe spasm. Several examples can be given to explain problems related to these factors the most common one being biting of teeth when angry or under stress or a habitual clenching of teeth at nights without himself/herself knowing it.

Treatment for all the common disorders affecting the temporo-mandibular joint is covered separately in the following topic, Treating TMJ Disorders.

*Disclaimer: This is not medical advice. The content is for educational purposes only. Please contact your doctor for any health care issues.