Expert: Steven C. Scherr, D.D.S. - 2/27/2004

Question
Hello!
  I'm a freshman in college, in good general health (as far as I can tell), and I've been experiencing a stiffness and soreness in my right jaw muscle for almost a month now.  It started when I was taking, or attempting to take, a bite of a large sandwich.  The muscle popped once, and since then I have been unable to open my jaw wide or bite down with any strength without experiencing moderate pain in my jaw.  I assumed I just "pulled a muscle," but it has lasted much longer than I originally assumed.  I'm not very familiar with disorders of the jaw, but might this be a form of TMJ?  In any case, do you have any suggestions on how to lessen the pain and/or speed the natural healing process?  Thank you for your time!

Answer
Wade,

You are right on track.  Yes, this does sound like a TMJ problem.  The TMJ, or jaw joint, is the hinge that allows the jaw to move.  Lets take a look at the anatomy of the TMJ so this will make a little more sense.

The TMJ consists of four main parts: condyle, articular eminence, disk, and capsule. The joint is held together by ligaments, and all joint movements are controlled by muscles. The condyle is roughly a ball-shaped nub of bone at the uppermost back extent of the lower jaw. It forms the lower part of the TMJ. The articular eminence is part of the skull and forms the roof of the TMJ. The disk is a soft tissue pad that sits between the condyle and articular eminence to keep the bones from grating directly against each other. The capsule is a fluid filled sack that envelopes the joint and provides lubrication and nutrition.

The joint functions smoothly when healthy. Cramped muscles or trauma can stretch and tear the ligaments that hold the joint together. Damaged ligaments allow the disk to be forced out of its normal position. This can result in  inflammation and pain. The displaced disk can also impinge on the sensitive neurovascular tissues surrounding the disk.  If the disk is out of position, it will initially prevent the jaw from opening completely.  Over time, the disk may become deformed.  Sometimes jaw motion improves as the malpositioned disk is repeatedly tugged and crushed. However, there continue to be health risks to the damaged joint.

Early professional attention is important.  The older the injury becomes, the harder it may be to fix.  In addition, there is up to a ten fold increase in the risk of advanced joint damage following a jaw locking episode.  CAT and MRI scans are often useful aids in determining the specific diagnosis. There are more than 50 different kinds of TMJ problems. The key to determining what type of treatment, if any, is right for you is to determine the cause and extent of any joint damage that may be present.

Wade, I suggest you see a dentist with advanced training in the treatment of TMJ disorders.  I wish you well.

Steve