The Neuromuscular Dentistry Scam
SUMMARY
"Neuromuscular dentistry" (AKA computerized diagnostic testing) is an attractive name for a TMJ and bite treatment philosophy that was developed half a century ago based on a false assumption that delivering transcutaneous electrical nerve stimulation (TENS) over the motor root of the jaw muscles will fire all the jaw muscles evenly. It doesn't. Today it provides a conceptual basis for marketing equipment that looks impressive but has no clinical relevance and provides no useful diagnostic information.
BACKGROUND
Neuromuscular dentistry was developed during the 1980's by a well known and loved dental researcher, Dr. Bernard (Barney) Jankelson, who thought he had discovered a way to use modern electronic technology to precisely identify and record the ideal centric (CR) bite position precisely, instead of depending on the manual techniques that had always been used by dentists. His sales line was, "If you can measure it, it's a fact. If you can't measure it, it's an opinion."
His technique for electronically identifying the ideal bite position involved placing a pulsing TENS (transcutaneous electrical nerve stimulation) machine on the patient's cheeks, over the motor root of the jaw muscles, to cause them to fire evenly, keeping it there for long enough to relax them all, and then turning up the amplitude of the TENS until it closes the mandible into the ideal bite. He called that bite position the "myocentric" position, and he claimed it was so important that the pathways into and out of it did not matter. He even marketed it with articulators that moved only straight up and down and permitted no lateral movement. To record this myocentric position, he included a jaw tracking device; and to record the expected relaxation of the jaw muscles, he included surface EMG. Eventually he started a company to market the pulsing TENS machine along with the jaw tracker and the EMG recorder as a treatment for TMJ and other bite related disorders.
When Dr. Jankelson was in his 80s and near the end of his life, the ADA gave his equipment its seal of approval. However, a flood of scientific research showed that the pulsing TENS machine does not work as intended. One study used needle electrodes to show that the jaw muscles don't respond to the TENS evenly. They respond in proportion to their distance from its source. In another study, the diagnostic equipment was unable to distinguish between TMJ disorder patients and healthy people. The jaw tracker is not nearly precise enough to record bite positions with the accuracy needed for restorative or prosthetic dentistry, and surface EMG is far too variable to be able to show relaxation of the jaw muscles.
However, when the ADA went to withdraw its approval for Dr. Jankelson's equipment, the dentists who had already bought it based on the ADA recommendation threatened to sue, and the ADA's hands were tied. They can never withdraw their approval without repaying all the dentists who bought the equipment based on their approval. In addition, the FDA cannot regulate the equipment, because their job is to evaluate safety and efficacy, and the diagnostic equipment is safe and effective at measuring what it measures, even if those measurements are clinically useless.
Freed from all regulations, the company has achieved so much success that about half of the dentists who advertise TMJ treatment use their equipment. Their latest marketing involves cementing a resinous "myoaligner" bite surface over the back teeth, which must be followed by crowns that recreate the biting surfaces which were engineered to fit the position determined by the non-diagnostic equipment - a significant expense for the patient.
Making an oral appliance to fit the position determined by pre-treating the jaw muscles with pulsing TENS sometimes relieves TMJ disorder symptoms, but not for the reasons claimed. Applying TENS over the cheeks usually shifts the lower jawbone anteriorly, because the muscles closest to the source of the TENS are the superficial masseters, which are oriented in a more forward direction than the other jaw closing muscles; and most TMJ disorders are caused by a lower jawbone that has been driven too far backward by the bite, not because TENS has some special ability to relax the jaw muscles. In fact, TENS is not used to relax muscles in medicine.