TMJ is an abbreviation for the temporomandibular joint. The TMJ is the joint that connects the temporal bone (a portion of the skull bone) with the mandible (the lower jaw bone). The TMJ is actually two joints in one, with the joints being connected by the jawbone. The TMJ is one of the most complicated and sensitive joints in the body. There are many soft tissues surrounding it, and more than one-third of all nerves that go the brain pass near this joint.
Your teeth dictate the TMJ’s function. While your teeth are “passive” components of your upper and lower jaw, they have a very specific way they must fit together in order to function properly. As far as the brain is concerned, your tooth position has priority over the joint position. Thus, your TMJ is forced by the surrounding muscles to move in whatever ways are necessary to allow your teeth to function properly. When this happens, the muscles can get caught between the tooth (priority) position and the jaw position. This compromising position can cause the muscles to spasm, resulting in facial pain and discomfort.