TMJ Chart


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The Great Imposters: TMJ and Myofacial Pain Dysfunction (TMD) Orthodontics, Dentofacial Orthopedics and Temporomandibular Dysfunctions Exclusively

by S. Kent Lauson, D.D.S., M.S.


Over forty million Americans suffer at some time from a Temporomandibular Dysfunction (TMD), an affliction that can be very painful and debilitating and which, unfortunately, is often misdiagnosed. Billions of dollars are spent each year by individuals consulting numerous doctors who cannot relieve their pain

Known as the “great imposter," a TMD or craniofacial pain disorder can, when properly diagnosed, be successfully treated for relief of symptoms over 90% of the time.

About the Temporomandibular Joint (TMJ)

The Temporomandibular Joint is the jaw joint in front of the ear connecting the mandible, or lower jaw, to the temporal bone of the skull. It is the most complex joint in the human body and its proper functioning is critical to the health and well-being of an individual. Inside the joint is an articulating disc of cartilage which is held and controlled by ligaments and muscles and which moves with the lower jaw as it opens and closes. Behind this disc is a rich supply of nerves and blood vessels.

Muscles of Mastication

A group of muscles known as the “muscles of mastication” control the movements of the lower jaw. These muscles coordinate movements each time a person closes his or her teeth together. Ideally, the teeth fit together normally with free, unrestrained hinge-like movements of the Temporomandibular joint. When this happens, a lifetime of normal joint function is possible.

Just What are Temporomandibular Dysfunctions (TMD)?

These disorders include dysfunctions of the TMJ and the structures directly relating to and affecting it. The problem may be related to pain in muscles controlling the lower jaw movements, or in improper positioning of the lower jaw within the jaw joint (TMJ).

What are common symptoms of Temporomandibular Dysfunction?

  1. Headaches and facial pain
  2. Neck aches or stiffness and back aches
  3. Ear pain, ringing, fullness and hearing loss
  4. Back of the eye pain and visual problems
  5. Clicking, popping and grinding in the jaw joints
  6. Limited or painful opening of the jaw
  7. Clenching, grinding and excessive wear of teeth
  8. Numbing in the fingers and hands

Although the symptoms listed are very common to TMD, many can be from other causes also. Because of this, a thorough clinical examination by a dentist specially trained to diagnose and treat TM dysfunctions should be completed.

Causes of Temporomandibular Dysfunction

Whenever the best fit of the teeth does not match the free, unrestrained hinge-like movement of the Temporomandibular joints, the muscles adjust their movements to allow the teeth to fit together best on closure. This happens because the teeth are abundantly supplied with nerves that provide a sense of touch. A strong neuromuscular message is sent to the brain which then directs the muscles to guide the lower jaw to close with the teeth fitting best.

If the difference between the best fit of the teeth and the ideal unrestrained movement of the TMJ is significant, then the muscles have to work very hard to accommodate each time a person closes his or her teeth together (reported to be up to 2000 times a day just during swallowing). This continual activity is hard on the muscles as they are constantly working to accommodate and are literally fighting each other as activity in one group of muscles causes bracing activity in opposing muscles. This eventually leads to lactic acid buildup and causes pain, spasms and shortening of the muscles. Further bracing of opposing muscles follows as the body attempts to protect itself. A vicious cycle has now begun. This condition is known as Myofacial Pain Dysfunction or MPD.

While this accommodation and dysfunction is occurring within the muscles, it is also having an impact within the TMJ. The movement of the lower jaw to accommodate to the teeth can cause the lower jaw (condyle) to become displaced. The displaced condyle and muscular spasms can cause the disc to become displaced. As the jaw opens and closes, the disc will literally click in and out of position causing it to become worn, deformed and dysfunctional in time. This condylar displacement can cause pressure against the posterior ligament and can pinch critical nerves and blood vessels which supply the ears, eyes and other facial structures. Painful inflammation can result.

Teeth improperly positioned for proper jaw joint function is by far the most common cause of TMJ dysfunctions. However, traumas such as blows to the jaw, whiplash and excessively wide opening of the jaw (during yawning and even dental procedures) are a common cause of TMD. Neck problems, breathing problems or even sinus problems can help to create TMD.


The treatment of these disorders is usually accomplished in phases, beginning with a thorough evaluation by a dentist specializing in treatment of these problems. A complete history of the symptoms and problems will be taken, the Temporomandibular joint and related muscles are palpated for tenderness; jaw opening measurements are taken, joint sounds are evaluated, x-rays, and other records are studied. If TM dysfunction is diagnosed, the first phase of treatment will be to correct the position of the condyle within the joint by means of a Myocentric Orthotic (a very special type of splint).

Treatment in the Computer Age

Over four decades of research have produced a revolutionary bioelectric instrument to precisely measure jaw movements. With the aid of a Computerized Mandibular Scan (CMS), it is possible to track and record jaw movements in three dimensions very precisely (within a tenth of a millimeter). This record along with Tomographic x-rays provides documentation of an existing TM dysfunction and help to provide a precise roadmap to health.

As previously stated, the first phase of actual treatment is to correct the position of the lower jaw within its joint through the use of a Myocentric Orthotic. Made of hard plastic, it is worn all the time (except to clean the teeth) and directs the patient to bite into a certain position. Because dysfunctional muscles are almost always a strong factor, they must be normalized to the greatest extent possible prior to making the Orthotic. Otherwise, many of the muscles will remain shortened and in spasm and healing will be slowed or will not occur.

The normalization of the muscles can be done by using a Myomoniter (a special type of transcutaneous electroneural stimulation or TENS) for approximately an hour prior to getting an actual jaw registration (CMS). With intermittent painless electrical pulses (similar to that used in a cardiac pacemaker), the Myomoniter gradually causes the muscles to relax and extend to a more normal resting length, and deprogram themselves by pumping out the lactic acid and other waste products lodged in the dysfunctional muscles. This also allows oxygen and other nutrients to flow in.

Once this initial muscle relaxation has taken place, the Computerized Mandibular Scan (CMS) is taken, which provides a precise target for a new, healthy neuromuscular bite. That precise bite is incorporated into the new Myocentric Orthotic created at the initial treatment visit. This oral appliance maximizes the healing rate, and for many, relief from symptoms can occur in a matter of hours or days. Others require weeks to see significant relief.

We typically see patients every week or two at first, and as progress is made, appointments can be stretched out to several weeks between visits. Those visits include monitoring of symptom levels to assess progress and further muscle treatments with a Dyna, (a type of TENS) to continue the muscle treatment process started at the initial seating of the Orthotic. Adjustments to the Orthotic may be necessary as more relaxation of the muscles occurs during these visits; however it is not uncommon for the Orthotic to not require any adjustments at all.

Once the new bite is in as comfortable and as physiological a position as possible, it is necessary to allow about 6 months of healing and stabilization to occur. As the original tooth positions were not compatible with correct jaw functioning, orthodontic/orthopedic treatment is almost always necessary at this point to move teeth to stabilize the bite permanently to the newly corrected neuromuscular position. Sometimes other work by another dentist is also necessary for the complete stabilization of the bite.

Other factors outside of this described treatment may have an effect on overall treatment success. These include patient attitude and commitment, stress levels, nutritional habits, postural habits, sleep habits and overall health of the individual. Additional professional treatment may be necessary to address spinal misalignment, neck or back muscle spasms or ear/eye problems. In addition, certain life habits may need to be changed before a permanent solution is achieved.

A Final Word…

Even though TM dysfunction problems can be quite complicated in nature, you don’t have to live with chronic pain or undiagnosed symptoms. With proper evaluation and treatment, your improvement can astonish you. Our patients average a 90% reduction in their symptoms with our method of treatment. Now that’s a lot of relief!