Jaw malalignment is the cause of most TMJ conditions. If one were to be involved in trauma, jaw malalignment will prevent the jaw from healing. This often makes patients think that it was all due to the trauma, when there was a pre-existing hidden condition that has kept them from healing.
Definition: Jaw Malalignment– a condition in which the teeth do not support the jaw in the same position as where the muscles suspending the jaw want the jaw to be. This requires the jaw muscles to accommodate to the tooth position, thus causing the jaw muscles and the trigeminal nerve to become hypertonic/hyperactive. This condition is present in over 95% of the population from suspected multigenerational dietary insufficiencies. This condition can be made worse by dental therapies.
There are two primary requirements of a well aligned jaw: one should bite and talk on the same trajectory (i.e. the lower jaw should not thrust forward or to the side during speech), and one should open and close on a fair arc. Typically, these criteria are assessed by watching one count from sixty to seventy. Overbites are a fairly reliable indication of the amount the jaw is out of alignment as most people want to bite end on end. Biting is a skeletal phenomenon, and speaking is a muscular phenomenon, and they should be on the same trajectory.
This assessment should be done from both a side perspective and an anterior perspective. Most of my patients that have major medical complications as a result of their bite have a shift in excess of 3 millimeters (=1/8 inch).
2.one should open and close on a fair arc. This assessment is best done by opening wide and closing on a thin object. With an object placed between the teeth the brain instantly recognizes that it no longer has to accommodate to the teeth, and will usually close to the relaxed jaw position.
Note: Both of these tests are often in error when done on patients with prior orthodontic treatment in which bicuspid extraction was performed. One would best assume that the jaw is malaligned if they have had orthodontic extraction therapy due to the way the upper anterior teeth retract, causing the lower jaw to posture excessively posteriorly.