The Components of TMJ Dysfunction

(Part 1 --- The Structural Component)

After over 20 years of experience in dealing with TMJ dysfunction, it is apparent to me the problem has two components; a structural component, and a stress component. This article is directed toward the structural component.

Oddly enough, the best information we have about what constitutes health in the TMJ has come to us from a study in anthropology. The researchers proposed that by selecting a large number of skulls which exhibited none of the skeletal problems associated with TMJ dysfunction, they might be able to discover some "common threads" or attributes which would constitute dental and TMJ health. What they discovered was very profound and has enabled me to develop the highly effective treatment protocol I use today for TMJ dysfunction. It has enabled me to treat the underlying "source" or cause of the problem rather than just the "symptoms" or results of the problem. Additionally, it can be done non-surgically and with little discomfort.

In the anthropology study, the criteria for skull selection included the following characteristics:

  1. The teeth could not exhibit any excessive wear.
  2. There could be no fracturing of the teeth.
  3. The teeth had to exhibit excellent periodontal support from the alveolar (supporting) bone.
  4. There could be no arthritic or degenerative changes in the bones of the temporomandibular joint (TMJ).

Even though the criteria for the skull selection were quite simple, the findings were extraordinarily profound. There were a number of attributes that each of these "healthy" skulls shared. Among the "common threads" of health that each of these skulls possessed were:

  1. The teeth were straight and in ideal occlusion.
  2. Both the upper and lower jaws were "centered" in the skull.
  3. The upper jaw was level on a horizontal plane. In other words, it was never "canted" up on one side.
  4. There were also no "slants" in the upper jaw.
  5. There were no "sideshifts" in the upper jaw.
  6. There was never an excessive "slope" to the upper jaw.
  7. A line drawn between the center of the temporomandibular joints and to a point between the two front teeth formed an equilateral triangle.

With a little thought, what becomes apparent is that the position of the upper jaw in healthy subjects has been defined in three dimensions. Not only as the ideal position of the maxilla (upper jaw) been defined, it has been absolutely related to TMJ health, periodontal health, and to esthetics (by way of symmetry).

So just what does all this mean? Let me explain. For there to be optimal health in the temporomandibular joint (TMJ), there must be a harmony between the joint itself and the way the teeth come together or occlude. What we now know is if that harmony does not exist, at least one, but possibly two or more of the following signs will be present. There will be excessive wear of the teeth, fracturing of the teeth, loosening of the teeth in their sockets, and/or TMJ dysfunction symptoms. As you will recall, these were the criteria used for skull selection in the anthropology study, and the findings have now been borne out clinically on live patients.

What are the symptoms associated with TMJ dysfunction? The symptoms of TMJ dysfunction are unbelievably diverse, both in nature and in severity. The most common symptoms are migraine-like headaches, which seem to come from behind the eyes or the side of the head. Also, there are the headaches or neckaches, which occur at the back of the head right where the neck attaches to the skull. People usually describe these neckaches as "tension headaches", as they are often associated with stress. The pain often radiates down into one or both shoulders.

Slightly less frequent, but occasionally more severe symptoms include vertigo (dizziness), ringing in the ears, lancing pain in one or both ears, hearing difficulties, stuffiness in one or both ears, light sensitivity in the eyes, ulcer-like pains in the stomach, low back pain, and poor posture.

More obvious, but less severe TMJ symptoms include clicking, popping, and/or grinding (crepitus) in the jaw joint; tenderness or pain in the jaw joint; sore or painful muscles in the head, face, or neck; difficulty in chewing; fatigue of the jaw muscles after prolonged chewing or talking; limitations of the range of motion of the lower jaw; locking of the jaw in either the open or closed position; clenching or grinding the teeth; sensitivity of the teeth; and deviation of the jaw when opening or closing the mouth.

Because the mandible (lower jaw) is kind of in a "sling" of muscle and tendons, the brain tells it to go wherever it needs to go to get maximum interdigitation of the teeth. (In other words, the best bite possible)

What factors can destroy or disrupt the harmony between the TMJ and the occlusion (bite)?

It could be something as simple as a single tooth that is slightly out of position, or a dental restoration (filling or crown) that is high or otherwise creating an interference preventing the TMJ from working in an unstrained way. I have seen a number of full-blown TMJ dysfunction cases, which exhibited severe symptoms, be totally resolved by adjusting a single restoration or relieving the bite on one tooth.

It could also come from the loss of one or more teeth, which have caused a collapse of the dental arch and/or a loss of vertical dimension. Vertical dimension could be thought of as the chin-to-nose distance, but it actually has to do with how far the lower jaw has to close before the teeth meet each other. In cases involving the loss of vertical dimension, treatment can sometimes be as simple as replacing the missing teeth and/or otherwise restoring an optimal vertical dimension. As you might have already surmised from this paragraph, orthodontic extractions could predispose a person to TMJ dysfunction.

Yet another problem which can cause TMJ dysfunction is an upper jaw (maxilla) which exhibits a side-shift, a slant, a cant, an excessive slope, an under-development or over-development and thereby forces the lower jaw (mandible) into a strained position when biting down. The only way to treat a problem of this derivation is to actually move or develop the maxilla into a more ideal position. The good news is that this treatment can be accomplished non-surgically and with minimal discomfort using a very light force with a dental orthopedic appliance.

As should be quite apparent at this point, a correct and definitive diagnosis is essential. That cannot be done without a study of the function of the patient's jaws and teeth by mounting their dental casts on an articulator, which can be programmed to replicate the functional movements of the patient's jaws. Additionally, there must be a three-dimensional analysis of the position of the of the patient's upper jaw. These two absolute prerequisites of a correct diagnosis are most often not done by those treating TMJ.