The research being done at the Ferreri Institute, (Brooklyn NY, USA) since 1983 has recognized the TMJ as the functional part of a greater structure, the "pelvis of the Skull". It has long since been known that there is reactivity from one part of the body to another known as the Lovett Brother Reactor. The interdependence becomes very important because research has indicated that most of the "back conditions" suffered by most people are really problems with the TMJ functions.
One of the most important discoveries made at the institute was the vital survival reflex found in the action of the TMJ muscles. When the jaw is clenched in time of possible danger, the muscles of mastication lock the sutures of the skull together and increases tension in the cranial dura (covering of the brian and spinal cord) by flexing the sphenoid. The muscles,the bones of the skull and spine protect the Central Nervous System from damage.
Every function of the TMJ has a dramatic reaction some place else in the body. If you have any chronic health problems, particularly if they relate to structure (grinding of teeth/dental alignment work) or digestion in any way, you should have the function of your TMJ and its muscles examined and corrected.