TMJ is an abbreviation for temporomandibular joint, therefore to say that someone has tmj is not really a diagnosis but rather the naming of a body part. It’s analogous to having a torn meniscus and giving it a diagnosis of “knee”. So let’s get a little more specific about the types of TMJ problems that patients can have.
About 98% of TMJ problems are muscle related, the rest being problems in the joint itself. Today, let’s talk about the 98% and leave the 2% for another time. There are 2 basic sets of muscles that move the jaw. Elevator muscles (as the name implies) move your jaw as you open and close. The positioner (or horizontal) muscles move you forward and back. These 2 sets of muscles work in conjunction with one another to perform all of the complex movements that we make during talking, chewing etc.
The way that the teeth fit together and function dictates the position and muscle movements of the jaw joints. If the fit and function of the teeth force some of the muscles to become overworked and fatigued, joint pain and facial muscle headaches are often the result. So what can be done to solve this puzzle involving the joints, teeth and muscles? You can’t really change the muscles or joint, so that leaves us with the teeth. And essentially what we do is take the fit and function of the teeth out of the equation and build a better bite on an appliance that fits over the teeth.
The most important thing an appliance (aka splint) must do is allow the joints to go to the position that allows the overworked muscles to relax and rest. I’d like you to think about the jaw joints like a baseball diamond. The most restful position for the muscles is like home base which in terms of tmj position means that it is seated in the socket. 1st, 2nd and 3rd base would be analogous to moving the jaw right, forward and to the left. So the bite that we create on our appliance needs to be in harmony with the joint being on home base where the muscles can rest. Next time, we’ll talk about what constitutes a good bite and how we create it on our appliance.
Photo by Seth Doyle on Unsplash