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What Is the J5 Myomonitor TENS — And Why Is It the Only Dental TENS That Matters for GNM?
Not all TENS units are the same — and in dentistry the difference is clinically critical. The J5 Dental TENS delivers ultra low frequency stimulation at 0.67 Hz — a frequency scientifically proven to relax masticatory muscles through neural mediation, not direct muscle stimulation. This distinction is what makes it uniquely capable of establishing a truly physiologic and unstrained mandibular rest position for accurate bite registration. Equally important — the J5 Dental TENS is the only TENS device with FDA 510K approval specifically for dental use. GNM teachings are grounded in this understanding. Many practicing in the broader neuromuscular arena, however, are unaware of this critical distinction — and numerous competing TENS units are being used clinically without dental-specific FDA clearance. This means the foundational step of muscle relaxation in NM treatment may be built on an instrument that was never approved for the purpose it is being used for — a gap that GNM specifically addresses through its rigorous instrumentation standards.
The History of the J5 Dental TENS — From Jankelson’s Original Vision to Today
The J5 Dental TENS did not arrive fully formed. It is the result of five generations of refinement built upon the original vision of Dr. Bernard Jankelson — the Father of Neuromuscular Dentistry — who developed the first Myomonitor, the J1, as a clinical instrument to objectively relax masticatory muscles through ultra low frequency neural stimulation. From the J1 through J2, J3 and J4 each successive generation refined the precision, reliability and clinical application of the device. The J5 — now officially designated the J5 Dental TENS by Myotronics — represents the current pinnacle of that evolution.
What remained constant through all five generations was Jankelson’s foundational insight — that muscles cannot be assumed to be relaxed. They must be measured before and after stimulation using objective EMG recordings to confirm that true physiologic rest has been achieved. This principle is the cornerstone of GNM diagnosis at Occlusion Connections — and it is why the J5 Dental TENS is not optional in the GNM protocol. It is essential.
Occlusion Connections is the only dental CE curriculum in the world that teaches the J5 Dental TENS at this level of clinical depth — not as a convenience tool but as a diagnostic instrument whose pre and post stimulation EMG data drives every treatment decision.
Literature Review of Scientific Studies Supporting the Efficacy of Low Frequency T.E.N.S. in the Diagnosis and Treatment of TMJ/ MSD
The following list below is a partial list of the large body of supportive evidence documenting the use and efficacy of ultra low frequency TENS (Transcutaneous Electro-Neural Stimulation).
Efficacy of Low Frequency TENS in the Diagnosis and Treatment of TMJ/ MSD
- The medical literature is clear and unequivocal – low frequency T.E.N.S. (0.5 – 10 Hz) is both safe and efficacious for muscle relaxation and pain control.
- Nicolae Chipaila, Fabrizio Sgolastra, Alessandro Spadaro, Davide Pietropaoli,
Chiara Masci, Ruggero Cattaneo, Annalisa MonacoCranio: The Journal of Craniomandibular & Sleep Practice 2014 VOL. 32 NO. 2, pp. 118-130. - It is also clear that low frequency T.E.N.S. has a high degree of specificity when utilized for craniofacial pain (Andersson, 1979; Eriksson et al., 1984; Chapman et al., 1979; Andersson et al., 1977; Andersson and Holmgren, 1975; Sjolund et al., 1982; Phero, 1987; Lasagna et al., 1986; Thomas, 1986; Pantaleo et al., 1983; Wessberg and Dinham, 1977; Konchak et al., 1988). (Over 44 studies internationally).
Evoked response while using wire EMG electrodes
Choi and Mitani at Osaka Dental University in 1973 applied the Myomonitor to 15 subjects and monitored the evoked response using wire EMG electrodes. The study concluded “The evoked EMG was recorded from the anterior portion of the temporal, the masseter, the anterior ventral of the digastric, and obicularis oris and the buccinator muscles…The Myo-monitor pulse stimulates the nerve trunks of the fifth and seventh cranial nerves at the superior mandibular notch percutaneously and it appeared to have afferent and efferent effects.”
Myo-monitor Stimulus is Transmitted Neurally
Using accepted intensity-duration methodology Jankelson, et al., 1975 demonstrated that the chronaxy values for Myo-monitor generated curves were well below those for direct muscle stimulation. Further verification of neural mediation resulted from the study of Williamson and Marchall, 1986 using succinylcholine. The study concluded “Succinuylcholine acts by competing with acetylcholine at the myoneural end plate and, therefore, no neurally stimulated muscle contraction under such conditions is by direct depolarization of the muscle itself. With the Myo-monitor evoking electrical impluses, there was no muscle contraction in either instance. This information would support the conclusion that they Myo-monitor stimulus is transmitted neurally.”
Multiple Site Monitoring
Fujii 1977 at the University of Osaka used multiple site monitoring to distinguish M wave and H wave response. Using multiple anatomically separate recording sites the study concluded “Two kinds of response were obtained with latencies of about 2.0 msec. and about 6.0 msec. respectively. The former was assumed to be a direct potential (M wave) and the latter a monosynaptic reflex potential (H wave).” The use of recording sites anatomically distant from the input stimuli is essential for valid conclusions using this methodology. In a 1988 study of Myo-monitor stimulation, Dao, Feine and Lund for unexplained reasons placed the recording needle proximate to the electrode stimuli site.
Stimulation is Neurally Mediated
McMillan et al., 1987 at the University of Hong Kong concluded that “Contraction of muscles of the upper and lower eyelids, the lateral aspect of the nose and the upper lip indicates stimulation of the facial nerve, in particular its zygomatic and buccal branches. The results of our anatomic investigation indicate that this effect is produced by the stimulation of the branches of the upper division of the facial nerve as they pass in a more or less direct anterior course over the preauricular region. These branches will then be directly beneath a surface electrode placed according to the standard protocol. Propagation of the Myo-monitor stimulus along branches from the buccal anastomotic loops of the nerve would ensure contraction of muscles of the upper lip and angles of the mouth…This observation supports electromyographic evidence and results of intensity duration tests that indicate muscle contraction resulting from Myo-monitor stimulation is neurally mediated.”
Latency and Conduction Velocity of Peripheral Motor Nerves
Goodgold and Eberstein examined eight individual investigative studies and found that normal distal latency and conduction velocity of peripheral motor nerves ranged from 2.1 to 5.6 msec. and 44.8 to 67.9 msec., respectively. They concluded that the latency to the obicularis oris which is innervated by the facial nerve in response to stimulation at the angle of the jaw, averages 2.5 to 3.0 msec. Basmajian summarized the results of six studies conducted by separate authors on peripheral nerve conduction velocity and found a range of conduction velocity between 37 and 73 meters/sec. Assuming the distance between the stimulation electrode and the wire recording electrode was approximately 2 cm, it should have taken .27 to .54 msec. for the pulse to travel this distance if the muscles were stimulated directly. This time interval is much less than the 1.85 to 4.4 msec. measured in the Dao study. This suggests the pulse must have traveled a much longer distance. A neurally mediated pulse would have: 1) .5 msec. charching the dermal capacitance, 2) neural conduction time of .7 msec. assuming a neural conduction pathway of 4 cm and conduction velocity of 55 meters/sec. which is the average of Basmajian’s review, 3) residual latency (delay at the myoneural junction) of .6 msec., 4) intermuscular delay of approximately .4 msec. depending upon electrode placement. Adding the sum of these phenomena we find the latency of 1.8 to 4.04 msec. as measured by Dao, et al. is well within the rage of neurally mediated response, despite their electrode placement.
Read More On — J5 Myomonitor TENS Science:
- Relaxing the Muscles with J5 Myomonitor TENS →
- Efficacy of Myomonitor TENS – More Published Literature →
- About the J5 Myomonitor TENS FDA 510K Status and Classification →
- Dental TENS Safety and Effectiveness →
- Contraindications for Ultra Low Frequency Myomonitor TENS →
- Not Every TENS Unit is FDA Approved for Dental Use →
Read More On — Core Concepts:
- Science of K7 Electro-Diagnostic Instrumentation →
- Science of Computerized Mandibular Scanning (CMS) →
- Myocentric: The Correct Bite Position →
- What Is Physiologic Occlusion? Why the Answer Determines Everything →
- Parameters of Physiologic Health: Post TMJ Treatment →
Read More On — The Original Science Behind GNM:
- SCIENTIFIC TRUTHS: Bio-Physiology & Objective Measurements→
- Why OC is Different — The Original Science Behind GNM Dentistry →
- Why Anterior Deprogrammers Fail the Complex TMD Patient — And What GNM Does Instead →
- Why Posterior Occlusal Support Matters — The Neurophysiologic Explanation →
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Written by Clayton A. Chan, D.D.S. — Founder and Director, Occlusion Connections | Las Vegas, Nevada
6170 W. Desert Inn Road, Las Vegas, Nevada 89146 | Telephone: (702) 271-2950
Leader in Gneuromuscular and Neuromuscular Dentistry