The Neuromuscular Dentistry Scam

SUMMARY

"Neuromuscular dentistry", (AKA computerized diagnostic testing) is an attractive name for a TMJ and bite treatment philosophy that was invented to provide a conceptual basis for marketing a technique requiring a package of diagnostic equipment that looks impressive but has no clinical relevance and provides no useful diagnostic information. The idea that dentistry should take the nerves and muscles into account when treating the teeth is obvious and appealing, but the only neuromuscular aspect of the technique that it employs the neuromuscular system in a machine that is supposed to find your ideal bite. It works by delivering electrical pulses to the neuromuscular system in the form of transcutaneous electrical nerve stimulation (TENS). The theory behind it is that delivering TENS electrical pulses over the motor root of the jaw muscles will relax them all evenly, and then increasing the magnitude of the pulsing will fire the jaw muscles all evenly and thereby close the mandible directly into the perfect centric bite location. However, locating the electrical pulses over the motor root of the jaw muscles does not fire them all evenly - it fires them in proportion to their distance from the source of the pulses.  

BACKGROUND

Neuromuscular dentistry was not devised as a scam. It was developed during the 1980's by a well known and loved dental researcher, Dr. Bernard (Barney) Jankelson, who thought he had found a better way to identify and record the ideal centric (CR) bite position than the previous manual techniques. He came up with the idea that he could precisely locate and record it electronically by 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, keep it there for long enough to relax them all, and then turn 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 at all. To locate and record this myocentric position, he included a jaw tracking device; and to record the relaxation of the muscles that was expected due to the 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. His sales line was, "If you can measure it, it's a fact. If you can't measure it, it's an opinion." 

When Dr. Jankelson was in his 80s and near the end of his life, the ADA gave his equipment its seal of approval. It became popular immediately, because TMJ disorders were among the most controversial topics in dentistry. After he died, a flood of scientific research showed that the pulsing TENS machine cannot work as intended.  One study used needle electrodes to show that it did not fire all the jaw muscles evenly, it just fired 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 any bite positions with the accuracy needed for restorative or prosthetic dentistry, and surface EMG is far too variable to be able to show a significant effect from treatment. 

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 latest marketing involves cementing a resinous "myoaligner" bite surface over the back teeth, which must be followed by new crowns that recreate the biting surfaces which were engineered to fit the position determined by the non-diagnostic equipment. 

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.