Understanding the Mechanics of the Jaws and Teeth

The jaw complex consists of the upper and lower jaws, left and right jaw joints (TMJ's), related muscles, and the teeth. How these components function is most important because of the fact that their dysfunction has such far reaching effects. The relationship between the upper and lower jaws and the joints that function between them work much like other bone and joint complexes in the body. Muscles are attached to both of the bones on either side of the joint, and those muscles create the movement through the joint. The jaw joints and bones function much the same, but also have two components that make their relationship unique in the body. The first is the fact that both joints must work together, as you cannot move the left side of the jaw without some similar movement of the right and vice versa. The second is the fact that as the upper and lower jaw bones approach each other (closing your mouth), the teeth meet. If they mesh together properly, the whole system functions fine. If they mesh together in a manner that forces the jaws out of alignment, problems develop. These problems are expressed in three areas. They are the teeth and gum problems, jaw joint problems, and problems of the head and neck. The teeth and gum problems are a result of the physical stresses applied to the teeth. These stresses come from two sources. One is the reciprocal force applied to the teeth as they force the jaw to move out of the natural skeletal relationship. The other source is the stresses applied from clenching or grinding the teeth. This is abnormal muscle activity stimulated by a reflex mechanism that senses that something is out of order. Clenching and grinding (bruxism) results in the teeth wearing down and/or the gums and bone receding. (Yes, I know, you were told that your gums were receding because you were brushing too hard, and you have bone loss because you don't floss, and you wear your teeth down because you're nervous, or "stressed", but we now know better.) The effects of these stresses are the following: Temperature Sensitivity, Abfractions (gumline notches in the tooth), Gum Recession, Bone Loss (Gum Pockets), Loose Teeth, breaking off parts of teeth, wearing or grinding down of the tooth surface, jaw joint problems that result from the alignment discrepancy include clicking or popping in the joint, pain in the joint, and locking of the joint(s) that limits opening or closing. These may occur in one or both joints, and occur in any combination. The joint sounds are due to the displacement of the cartilage disk in the joint, much like cracking your knuckles. The pain usually comes from the muscles attached to the joint or nerves being pinched due to the abnormal position of the joint. The locking of the joint is due to the cartilage disk being displaced such that it interferes with the joint opening or closing The head and neck problems are the most common of the symptoms of jaw joint dysfunction. These problems are: Headaches (all kinds, including migraines), Earaches, Ringing in the Ears, Otitis Media in children, Sinus Pain, Sinus Congestion, Pain in or behind the Eyes, Pain or tenderness in the jaw muscles, false toothaches, neck muscle stiffness or pain, pain radiating to the shoulders and arms, pain or tenderness in the back muscles. These signs and symptoms I consider to be highly indicative of TMJ. The presence of any of these would prompt me to evaluate carefully for cranio-mandibular dysfunction.