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 introduced in 1967 by a well known and loved dental researcher, Dr. Bernard (Barney) Jankelson, who thought he had discovered a way to use electronic technology to record the ideal centric (CR) bite position, instead of depending on the manual techniques that had always been used by dentists. He used to say, "If you can measure it, it's a fact. If you can't measure it, it's an opinion."
His technique involved placing a pulsing TENS (transcutaneous electrical nerve stimulation) electrode on the patient's cheeks, over the motor root of the jaw muscles, keeping it there pulsing for 1/2 hour, 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 his equipment 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. Then a flood of scientific research undermined it. One study used needle electrodes to show that TENS does not stimulate the jaw muscles evenly; it stimulates them in proportion to their distance from the source of the TENS. 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 regulations, the company has been so successful that most dentists believe that it relaxes muscles, although TENS is used in medicine for pain relief by acting on nerves, not for relaxing muscles.
Making an oral appliance to fit the position determined by pre-treating the jaw muscles with pulsing TENS sometimes relieves TMJ disorder symptoms, because it shifts the mandible 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 mandible that has been driven too far backward by the bite.