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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.
Regulatory Recognition of the J5 Dental TENS
The J5 Dental TENS holds a distinct regulatory position among all TENS devices used in clinical practice. Where most TENS units are FDA-cleared for general musculoskeletal applications, the J5 Dental TENS is FDA-cleared under 510(k) specifically for dental use — a clearance no competing TENS device holds. This dental-specific clearance is not a technicality. It reflects that the J5 Dental TENS has been evaluated and cleared for the precise clinical purpose for which it is being used in GNM and neuromuscular dentistry: relaxation of masticatory musculature through ultra-low-frequency neural stimulation for the establishment of physiologic mandibular rest position.
The Myotronics J5 Dental TENS operates within the broader regulatory framework established for the K7 Evaluation System. The American Dental Association’s Council on Scientific Affairs awarded the K7 system its “Seal of Acceptance” as a diagnostic aid in the management of temporomandibular disorders, with K7-specific Acceptance Seals granted in October 2001 (K7/EMG), November 2003 (K7/CMS and K7/ESG), and extended across all K7 modalities in April 2004.¹ The ADA Seal Program for professional products was subsequently phased out effective April 29, 2007, as an administrative discontinuation of the program rather than a clinical determination about TMD instrumentation. The J5 Dental TENS continues to hold its FDA 510(k) clearance for dental use today, independent of the ADA Seal Program’s discontinuation.
The clinical implication is significant. When generic TENS units are used in dental practice — units that were never cleared for dental application — the foundational diagnostic step of muscle relaxation is being performed with an instrument operating outside its regulatory clearance. The clinician may achieve some level of muscle relaxation, but the methodology cannot be defended on regulatory grounds, and the relaxation cannot be guaranteed to operate through the neural-mediation pathway the dental literature documents for ultra-low-frequency stimulation. GNM dentistry is built on the J5 Dental TENS specifically because it is the only instrument whose dental clearance, frequency parameters, and clinical purpose align with the diagnostic role it is being asked to perform.
For the broader regulatory framework and chronological documentation, see our companion pages: Science of K7 Electronic Diagnostic Instrumentation → and Computerized Electro-Diagnostic Instrumentation →.
The Etiologic Value of the J5 Dental TENS
The clinical value of the J5 Dental TENS extends beyond muscle relaxation. The J5 occupies a unique position among the K7 measurement modalities — it is the only instrument that is simultaneously therapeutic and diagnostic. Surface electromyography measures. Computerized mandibular scanning measures. Electrosonography measures. The J5 Dental TENS does something — it delivers ultra-low-frequency neural stimulation — and that intervention is what makes objective pre and post measurement of the masticatory system possible.
Bernard Jankelson’s foundational insight, preserved through five generations of Myomonitor refinement, is that muscles cannot be assumed to be relaxed. The patient who reports feeling relaxed is often holding chronic compensatory activity the patient cannot perceive. The clinician who observes apparent rest is often observing adaptation to a non-physiologic state. Without an intervention that objectively reduces resting muscle activity, the clinician has no way to know what physiologic rest looks like in the individual patient — and therefore no way to know whether subsequent treatment has restored it.
The J5 Dental TENS resolves this problem methodologically. Pre-TENS resting EMG documents the patient’s baseline state — typically elevated, asymmetric, and reflective of chronic compensation. Post-TENS resting EMG documents the patient’s relaxed state — the physiologic floor against which any subsequent treatment intervention can be measured. The difference between these two readings is not just clinical information. It is the establishment of the diagnostic baseline that makes the entire four-channel convergence framework possible. Without the J5, there is no defensible pre-treatment measurement. Without a defensible pre-treatment measurement, there is no way to demonstrate that orthotic therapy has produced mechanical correction rather than symptom management.
This is what distinguishes the J5 Dental TENS from a comfort device. The J5 is not delivering relaxation as an end in itself. It is establishing the methodological reference point against which every subsequent measurement is interpreted. The pre-treatment Scan 9 resting EMG, the pre-treatment Scan 2 trajectory captured with relaxed musculature, the pre-treatment Scan 11 recruitment baseline, the pre-treatment Scan 15 joint signature recorded during a relaxed swallow — all of these depend on the J5 having established a physiologic baseline first. Subsequent post-treatment measurements then document whether GNM orthotic therapy has shifted the masticatory system toward, away from, or beyond that baseline state.
The J5 Dental TENS is therefore not optional in GNM protocol. It is the instrument that makes the convergence framework empirically falsifiable. Without it, the GNM clinician is back to claiming improvement based on patient report. With it, the clinician can document with measurement what the orthotic actually changed.
For documented case examples of pre and post TENS K7 measurement responses, see The Evidence Behind GNM →.
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.
- Chipaila N, Sgolastra F, Spadaro A, Pietropaoli D, Masci C, Cattaneo R, Monaco A. The effects of ULF-TENS stimulation on gnathology: the state of the art. CRANIO: The Journal of Craniomandibular & Sleep Practice 2014;32(2):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).
The J5 Dental TENS in clinical application — myotrodes positioned over the coronoid notches for neurally mediated masticatory muscle relaxation.
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 orbicularis 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 Marshall, 1986 using Succinylcholine. The study concluded “Succinylcholine acts by competing with acetylcholine at the myoneural end plate and, therefore, any neurally stimulated muscle contraction under such conditions is by direct depolarization of the muscle itself. With the Myo-monitor evoking electrical impulses, there was no muscle contraction in either instance. This information would support the conclusion that the 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.
J5 Dental TENS in clinical application — used together with K7 sEMG and ESG measurement to objectively document pre and post stimulation muscle and joint response.
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 distal latency and conduction velocity of peripheral motor nerves ranged from 2.1 to 5.6 msec. and 44.8 to 67.9 m/sec., respectively They concluded that the latency to the orbicularis 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. charging 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 range of neurally mediated response, despite their electrode placement.
References
¹ Chronological Overview of Myotronics ADA Seal Programs (Myotronics archival document). Documents K6 and K7 Acceptance Seal dates and the April 29, 2007 program phase-out. Sourced May 18, 2026.
Continue Learning
🔹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 →
🔹Core Concepts:
- Science of K7 Electro-Diagnostic Instrumentation →
- Computerized Electro-Diagnostic Instrumentation →
- Science of Electromyography (sEMG) →
- Science of Computerized Mandibular Scanning (CMS) →
- Functional Electrosonography (ESG) →
- Myocentric: The Correct Bite Position →
- What Is Physiologic Occlusion? Why the Answer Determines Everything →
- Parameters of Physiologic Health: Post TMJ Treatment →
🔹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 →
🔹Ready to Train:
Originally published May 9, 2015. Last updated May 19, 2026.
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