Wednesday, July 29, 2009



The following are important features that have been considered when using electronic instrumentation in NMRG's clinical research.

SURFACE ELECTROMYOGRAPHY (Surface EMG):It is important to be aware, when investing in neuromuscular electro-diagnostic instrumentation, that low noise distortion in the wires and software is an integral factor in the quality and accuracy of data collection. Line noise, external room interferences and sensor array distortion can influence data collection. This can produce flawed and inaccurate data and interpretation. The K7 Evaluation System is noise-free, clear and easy to interpret with precision.

SIMULTANEOUS EMG bite registration capability – this modality is a critical component to visualizing muscle activity in real time while using jaw tracking. This feature is automated with the K7 technology, making this technology unique and desirable for clinical research.

ELECTRICAL NOISE IMMUNITY – A necessity for consistent accurate data collection in order to discern between good data and environmental noise. Some technology on the market today picks up 60 Hz noise along with the patient EMG activity. This is unacceptable in a parameter where value lies in its accuracy.

EMG NEUROMUSCULAR FUNCTION CLENCH TEST – Real time integration EMG capability is a must feature for easy discernable comparative tests and evaluation of muscle balance and muscle recruitment. The monitor display should have the ability to analyze the entire clench without converting from raw data to processed data. (Important clinical feature for reconstruction/ TMD cases). This feature is a must when evaluating technology for clinical use.

EMG MONITORING MODE – This feature is available to provide the clinician real-time bio-feedback to the patient and clinician on all K7 Evaluation Systems.

OCCLUSAL PREMATURITIES IDENTIFICATION – A feature that is important to produce diagnostic data for clinical application and research, not just interesting graphics.

SPECTRAL ANALYSIS on EMG to determine muscle fatigue is a unique feature available with K7 technology.

EMG leads today are required to comply with FDA directives requiring "protected pins" on patient connected lead wires. Rather than a “quick” fix” of gluing leads into the preamplifier, Myotronics technology has a history of complying with these stringent directives in spite of the costly changes in manufacturing costs. The K7 model has the new, safety connectors incorporated in the basic design. Make sure your technology complies with FDA directives for patient safety and compliance.

The following should be considered in optimizing the use of neuromuscular instrumentation when using it to take a bite registration:

LEVEL OF ACCURACY - The K7 technology is set at a default gain of 1 mm when taking a bite registration. Competing technology display a default of 2-5 mm gain. This is important in regards to the level of accuracy our Clinical Research Associates are able to record a bite registration.
Having instrumentation that has the capability to take bite registration accurately is one of the key reasons NMRG research is accurate and reliable. The technology should be able to synchronize EMGs with jaw tracking simultaneously and display it in real time on the same display rather than having to flip from window to window.

The Myotronics K7 is designed to do TREATMENT as well as document.

COMPREHENSIVE SENSORY ALIGNMENT FEATURE is critical to properly align each scan before data collection. Graphic representation of how to adjust the sensor is needed so the data is consistent and not compromised.

ELECTRICAL NOISE IMMUNITY – The K7 picks up virtually no system noise giving our Clinical Research Associates accurate data readings unlike noise caused by poor system design and inexpensive components used.

IMMUNITY TO MOVEMENT OF OBJECTS - The jaw tracking signal should not be susceptible/ “contaminated” by any movement of metal or non metal objects that might not normally come within four feet of the patient (rings, watches, towel clips, dental instruments, etc.) nor by minor to moderate head motion.

MAXIMUM DEFLECTION of the cursors should not exceed 1 mm. When the doctor’s hands are placed near the patient’s mouth and between the sensor array there should not be any deflective movement of the cursor. The K7 has this capability. Any motion of the operator around the system should not diminish the signaling.

Fine versus thick sweep lines are clearly displayed while the patient is at habitual C.O. The K7 passes the No noise test when performing a no movement test in both the vertical, A/P and lateral dimensions.

Velocity tracings on opening and closing cycles yield visually readable lines on the monitor to discern smooth versus sporadic movements of the jaw.

SENSITIVITY TESTING – The K7 Evaluation System is immune from any distortions of tracings when moving the hand within three feet of any sensor array unlike other instrumentation.

SENSOR ARRAY: Myotronics sensor array weight is 6 oz only. It is attached via velcro straps around the head to avoid direct contact to the mandible.

WEIGHT OF THE SENSOR ARRAY is significant in that it can effect posture, patient comfort and impede muscle relaxation. The K7 sensor array passes the NMRG test of light weight compared to other heavier sensor arrays of 13-14 oz. This can be extremely uncomfortable and clearly not conducive to patient relaxation and clinical research.

LOW INHERENT NOISE for a more accurate and easier to discern diagnostic data. Noise can be interpreted as patient information leading to an incorrect diagnosis.

The K7 by Myotronics is extremely stable. When performing the sensitivity test it has been observed that any hand movement with objects or no objects produced stable, consistent, readable data on the monitor with no distortion. This is again significant when taking a bite registration and collecting accurate data.

ELECTROSONOGRAPHY:BALANCED SOUND TRANSDUCER DIAPHRAGMS should be able to record clear, undistorted joint vibrations.

UNOBSTRUCTED TRANSDUCERS - Transducers should be placed directly over the skin rather than a dome of solid silicon between the transducer and the skin which would reduce the ability to pick up soft sounds in the joint.

It is imperative that this technology has the capacity to distinguish low frequency noise from high frequency noise, a significant feature in distinguishing joint noise diagnostically and accurately.

UNLIMITED FILTERING CAPABILITIES – The Myotronics Sonography has the capability to filter out loud joint sounds (clicks, pops, etc.) that might be masking the high frequency of degenerative joint disease sounds. This gives the doctor a better picture of what is going on in the joint during function.

Electro-sonographic technology should have the ability to read an entire range of joint sound vibrations. Recording of both the low frequency joint vibrations as well as the high frequency joint vibrations at the same time should be available. This will eliminate having to retake data, save time and avoids loss of good data. The Myotronic electro-sonographic features have met these challenges.

An ultra low frequency TENS (Ulf TENS) units used in our research delivers a “simultaneous” and “bilateral” pulse effective for accurate bite registration physiologically. The Ulf TENS is 3 electrode lead system rather than just the common two electrode lead systems – This feature is important to relax not only the masticatory muscles, but also the cervical neck region. (This is critical for establishing an optimal mandibular position during research). The cervical neck region is a critical part of the mandibular masticatory system that should also be relaxed for optimal posture and bite recording. NMRG choses Myotronics J5 Myomonitor and BNS-40 TENS units because of their capability in delivering a “simultaneous synchronous pulse bilaterally” unlike competing manufacturers that produce an alternating stimulus to the mandible. The TENS units our Clinical Research Associates use at NMRG are the patented 3 electrode lead system which many in the neuromuscular arena do not realize is an important aspect that establishes muscle rest for both the masticatory and cervical neck region. A frequency that has shown to be most effective by most muscle physiologist is a frequency below 2.0 Hz with a biphasic wave form stimulus between 150-500 milliseconds. The J5 Myomonitor has a set frequency of 0.67 Hz and stimulates every 1.5 seconds.

BITE REGISTRATION APPLICATION:The ultimate evolution of Jaw Tracking and EMG Technology.

We have chosen the K7 since it is designed for clinical bite registration of TMD, fixed and removable prosthetic, orthodontics and diagnostic bite recordings. It was designed by clinical dentists for clinical ease and precision of optimal bite registration. The technology chosen has the unique features of combining simultaneous three dimensional real time sweep and sagittal/frontal display of mandibular position with real time graphic display of eight channel EMG for precise identification of mandibular rest position and optimal bite recording.

The K7 Evaluation technology comes complete with an automated bite registration capability for treatment that is automated to display a neuromuscular trajectory.

PRECISE MARKING OF THE OCCLUSAL BITE POSITION – Necessary for easy to use Myocentric Targeting with graphic software allows for precise placement of the occlusal bite position to within 0.1 mm precision prior to final bite registration. (A key feature for accuracy and precision using a gain = 1mm).

RECORDING BITE REGISTRATION WHILE MONITORING EMGs – A visual display and data analysis of real time EMG is used to insure optimally relaxed masticatory muscles.

SIMULTANEOUS JAW TRACKING AND EMG CAPABILITY enables our Clinical Research Associates to guide the mandible to optimum myocentric bite position while viewing the real time EMG to insure optimally relaxed musculature.

FIRST TOOTH CONTACT EMG MONITORING MODE - Finishing the bite/ or adjusting the bite is critical for any restorative dentist, thus today’s technology should have EMG monitoring modes to guide the doctor to balanced musculature in both function and resting modes when coronoplasty/ equilibrating the occlusion. Myotronics is the only technology that displays first tooth contact with simultaneous EMG to assist in identifying where to adjust the bite in micron levels (Scan 12) and optimal occlusal testing.

The American Dental Association’s Council on Scientific Affairs has awarded surface electromyography (SEMG), computer mandibular scanning (CMS), and Sonography its “Seal of Acceptance”, as diagnostic aids in the management of temporomandibular and occlusal disorders.

The U.S Food and Drug Administration has granted 510K status to each of these mentioned devices for use in the diagnosis and management of musculoskeletal occlusal disorders.

Disclaimer Statement:
Dr.Clayton Chan and the NM Research Group have no vested financial interest in Myotronic-Noromed, Inc or any organization. This information is provided to substantiate this organizations unbiased, integritous research and findings while using neuromuscular technology for quantitative analysis and research.

To discover the latest and most up to date information on GNEUROMUSCULAR Dentistry and the latest in Dental Continuing Education CLICK:

© 2008 Occlusion Connections All Rights Reserved

Neuromuscular Dentistry