#129 How Does TMD Cause My Jaws to Lock?

One of the most common symptoms of Temporomandibular Joint Disorder, (TMD), is the inability to open the mouth fully causing the jaws to be locked partially closed. Patients usually complain that opening widely to eat, sing, yawn, or during a dental appointment causes pain.   

It was previously thought that the inability to open the mouth widely was caused by the overused and sore muscles that controlled jaw motion due to constant clenching and grinding of the teeth, (Bruxism).  But that explanation, although sounding reasonable, does not adhere to the science that has proven all the symptoms associated with TMD are directly caused by inflammation within the joint, (TMJ).  It is inflammation within the joint that causes joint locking. 

To understand how inflammation inside the jaw joint causes locking you first need to understand a little about the anatomy inside the jaw joints. 

The TMJ is like other joints in the body, in that it consists of a ball and socket arrangement.  Between the ball and socket is a small disc made of cartilage about the size of a nickel surrounded by ligaments which suspend it in place above the ball and below the socket.  This cartilage is responsible for keeping bone from rubbing on bone when it is its normal position.   

The most important component of a healthy joint is the lubricating fluid that occupies the inside of a joint and lubricates the inside of the joint like motor oil lubricates the inside of an engine while all the parts are in motion. Instead of calling the joint lubricant an oil, doctors have named this lubricant Synovial Fluid because it is secreted by the synovial tissue lining every joint.  Synovial fluid is a very fine lubricating fluid with much more lubricating characteristics than the finest lubricating oil used on expensive wristwatches. 

As has been discussed in many of the earlier articles in this series, TMD is nothing more than the symptoms created by chronic inflammation inside the jaw joints secondary to three varieties of joint damage.  Once the jaw joints are damaged due to bruxism, acute trauma, or functional malocclusion of the teeth, chronic inflammation occurs.  Chronic inflammation is the continuation of the inflammatory process way beyond normal healing.  Basically, chronic inflammation is a wound which does not heal properly. 

And here is the key that explains why chronic inflammation causes joint locking. CHRONIC INFLAMMATION CASUES THE SYNOVIAL FLUID TO BECOME STICKY LIKE GLUE INSTEAD OF SLIPPERY LIKE A LUBRICATING OIL. When the synovial fluid becomes like glue it causes the ball to stick to the disc pushing it forward and dislocating it out of position.  The ligaments that suspend the disc between the ball and socket are like rubber bands and tend to snap the disc back into place, usually with a loud noise and some pain.  After a while, the ligaments lose their elasticity, and the disc is now permanently pushed forward and works like a door stop underneath a door keeping it from opening all the way. 

Sometimes the patient can open their mouth ¾ of the way, ½ of the way, and sometimes only a few millimeters.  The decrease in the ability to open widely is usually progressive over time.  Sometimes it occurs so slowly that the patient is not aware there is a problem until they need some dental work toward the back of their mouth and the dentist is unable to accomplish what needs to be done.   

The good news is when the patient rests the jaw joints by placing a device between the front teeth according to a protocol that allows the chronic inflammation to subside, the inside of the joint heals, the synovial fluid recovers its lubricating properties and the dislocated disc slides into a more normal position. The patient will then be able to open their mouth again pain free. 

Now you know how chronic inflammation of TMD causes jaws locking and how the Urbanek Device and Protocol corrects the locking.