Neuromuscular Myth Busters: A Common Sense Evolution of NMD

Dr. James 'Jim' Harding, DDS

  • Practices in Colorado
  • Graduate of University of North Carolina
  • LVI Clinical Instructor since 2001
  • Founding and current board member of the IACA
  • Past President of the IACA (Orlando 2007-2008)
  • Official dentist of the US Ski and Snowboard Teams
  • Board member of Ski and Snowboard Club Vail
  • Board member of Vail Ski and Snowboard Academy
  • Married with two children

Brief HIstory of NM Dentistry: It all started with Dr. Bernard Jankelson in the 1960s

  • Bernard Jankelson, 84, Dies; Expert on Jaw Malfunctions
  • Special to the New York Times
  • Published: April, 1987
  • Dr. Bernard Jankelson, a dentist and a pioneer researcher in cranio-mandibular orthopedics and the study of head pain traceable to jaw malfunction, died here Monday. He was 84 years old.
  • When he was 67, and after 45 years as a specialist in prosthodontics, Dr. Jankelson began research that led to the development of electronic devices to relax muscle tension and instruments to measure muscle status in jaw action.
  • In an interview last year he explained his work as the investigation of ''maladjustments in the relationship of the jaw to the skull which cause sustained muscle tension.'' He said he had found jaw movement malfunctions to be at the root of many health problems, ranging from headaches to insomnia.
  • Born Sept. 8, 1902 at Bloemfontein, South Africa, he was reared in Saskatchewan and graduated from North Pacific College of Dentistry in 1924, now part of the University of Oregon, where a memorial fund to him has been established. He is survived by his wife, Agnes; two sons, Dr. Robert Jankelson of Seattle and Roland Jankelson of Tacoma, Wash.; a sister, Cecilia Magnuson of Seattle, and four grandchildren.

Neuromuscular Historical Timeline

  • 1964: Development of first ultra-low frequency electrical muscle stimulator (TENS or Myomonitor) by Dr. Bernard Jankelson. Used to relax the facial and masticatory muscles through gentle, repetitive stimulation via the neural pathways.
  • Early 1970s: First Mandibular Kinesiograph (MKG) built by Bernard and his son Dr. Robert Jankelson. "A unique and innovative instrument to track and record the position of a fixed point on the mandible in three dimensions." (K = Kinesiograph...I can't tell you how long it was before I knew that!)
  • 1975: The first commercial model of the MKG was introduced. Because this predated personal computers it was "virtually a home made computer attached to an oscilloscope."
  • 1976: Jim Garry (Pedodontist) who becomes the preeminent expert on airway takes his 1st NMD course from Dr. Jankelson which not only saves the life of his sister but also alters the history of NMD because of the connections he establishes with arch arch development and TMD.*
  • 1977: A group of international doctors who had studied under Dr. Jankelson and used the Kinesiograph known as the K5 gathered in Hawaii. During this meeting it was decided to form an organization to support neuromuscular dentistry
  •  1979: ICCMO was formed. The International College of Cranio-Mandibular Orthopedics included names like the Jankelson(s), James Garry, Norm Thomas among many other NM pioneers. 
  • 1979: Dr. Barry Cooper (himself a TMD sufferer) takes a course from Dr. Jankelson and goes on to publish many articles on NMD and later serves as the International President of ICCMO
  • 1981: Introduction of Surface Electromyography (SEMG). Allows the NM dentist to now actually see how much relaxation is achieved through TENS. 
  • 1986: NMD instrumentation was recognized by the ADA Council on Scientific Affairs as being safe and effective for it's intended purposes. (USFDA in July 1994)
  • 1987: Dr. Bernard Jankelson ("The Father of NMD") dies at age of 84 but his son Dr. Robert Jankelson who had been working by his father's side steps in to become the leader of NMD
  • 1987: Dr. Norm Thomas was elected Chancellor of College of ICCMO. This honor was "bestowed on him in recognition of his contributions as a teacher, researcher, author, mentor and beloved friend of NMD" 
  • 1989: TM joint sound detection (sonography) is introduced. Known as joint vibration analysis
  • 1990: Dr. Robert Jankelson publishes the classic textbook of neuromuscular principles. Neuromuscular Dental Diagnosis and Treatment
  • 2000: Bill Dickerson adopts NMD for LVI and in many ways brings NMD to the forefront of dentistry. For much of the first 40 years only small pockets of NM dentists existed. Many of those were outside of the US in places like Italy, Japan and South America. LVI has exposed thousands of dentists to NMD as well as creating a whole new generation of foot soldiers and "lamplighters" (Bill's gift is the ability to understand the parts of NMD that were relevant in real world dentistry)
  • 2000: Many of NM "giants" begin to teach courses at LVI as they quickly realize the importance of what LVI has to offer NMD

Some of the Important Contributions of LVI to Neuromuscular Dentistry Over the Last 10 Years

  • LVI Fixed Orthotic is introduced and taught to the students at LVI which becomes a major revolution in how full mouth reconstruction cases are set-up before treatment
  • LVI, after evaluating and documenting thousands of cases through the live patients courses adopts the "EMG's Rule." This allows for a more accurate myobite and much less occlusal adjustment during Phase I because the muscles guide the bite into a better physiologic position
  • CO rest split screen is developed to demonstrate muscle activity in slight contact. Teeth come together thousands of times a day. If they are required to overwork in this position that is a recipe for pain
  • LVI Golden Proportion 

Some of those who have dedicated so much of their lives to the cause of NMD besides the Jankelsons. 

  • Dr. Bill Dickerson (LVI becomes the marriage of form and function of NMD)
  • Dr. Jim Garry (Pedodontist who describes how airway and facial development affected the normal formation of the jaws and face) 
  • Dr. Mike Mazocco (Advanced scan interpretation and orthodontics)
  • Dr. Jay Gerber (NMD orthodontic education)
  • Dr. Gary Wolford (Understanding of mandibular closure pathways)
  • Dr. Barry Cooper (published many articles, International President of ICCMO)
  • Dr. Brian Alman (Advancement of Sleep Dentisrty and NMD)
  • Bill Wade (renowned NM Technician and educator..."nuts and bolts of NMD") 
  • And too many others to name them all!!

"Simple" myths about NMD that are more of a reflection of a pure lack of understanding or ignorance

  • Most, if not all of these have been discussed extensively over the last decade.
  • I cover these here for the benefit of dentists and team members who are newer to NMD and might not have heard this before

NMD and the "lack" of science argument

  • NMD in many ways is more of an advancement of the oldmechanical belief of how occlusion works than some radical theory
  • Thousands of studies have been completed over the past 40+ years to validate NMD...Sahag's books Volume I and II as well as Myotronics NMD Literature Review 3rd Edition are great resources to demonstrate "the science"
  • Many of these published studies have occurred in international, scientific, peer reviewed journals and represent true science, not just opinion
  • NMD can record data and information about the muscles, joint, and teeth with an accuracy and understanding which could not be imagined before Dr. Jankelson
  • The argument or "myth" seems silly when you look at reality

TENS could not possibly relax the lateral pterygoid!

  • Essentially this is an ignorant statement made by people who do not understand TENS and physiology
  • TENS has been proven to stimulate the V and VII cranial nerves neurally and not on the surface
  • Since the Lateral Pterygoid is innervated by the mandibular branch of the 5th (trigeminal) cranial nerve. This is the same as with all muscles of mastication
  • In reality, this statement should not even be listed as a myth

NM dentists simply allow the "computer" to take the bite

  • "The use of scientific instrumentation allows the NM dentist to objectively quantify and validate the occlusion."
  • Computer never "takes the bite (Kois)." The dentist chooses the bite position within the zonebased on data and professional opinion. The "zone" varies from patient to patient. This is where the narrow vs. wide goal-posts quote or discussion comes from
  • Many dentists are intimidated by technology like the Myotronics K7 and J5 Myomonitor (TENS). However, those of us who have used this instrumentation would never want to practice comprehensive dentistry without the information gained from these devices. This is especially true of the "narrow goal-posts patients"
  • Again, what other profession would turn it's back on technological advances and the use of modern computer instrumentation? Could you imagine a cardiologist only using a stethoscope to diagnose heart disease?

NMD can't work because it is not the most comfortable mandibular position

  • The NMD position, which is often times "down and forward" of the CR position has never been shown not to be a comfortable position in any research paper I could locate
  • Just because a position is repeatable (CR) does not make it right!
  • Several years ago LVI conducted a study comparing NM, CR and CO. The results were very conclusive that the NMD position was reported by the patient to be the most comfortable, but perhaps more importantly, the EMG readings were clearly in the most relaxed position.
  • This goes back to the same lack of understanding of physiology by being stuck in a mechanical paradigm of occlusion

NMD Cases

  • While there are many cases which turn into full mouth reconstruction there are MANY MORE cases which are treated conservatively with removable orthotics, OSA sleep appliances, coronoplasty, and/or orthodontics
  • Neuromuscular dentistry is not good in the hands of dentists who skip steps and don't have a great appreciation to detail. In many ways, this is the most important point. We must not be careless and give these doubters ammunition!
  • I strongly feel some of the most ethical, caring, and talented dentists I have ever met are neuromuscular dentists! I find many of them to not only be passionate about our profession but also to be life-long learners who are committed to being the best possible dentist they can be!!!

More "complex" arguments from the occlusion debates

  • Mechanical Models of Occlusion vs. Neuromuscular/Physiologic Dentistry
  • Where does Obstructive Sleep Apnea Fit Into Occlusion?
  • The "Dreadful Story"

Does the jaw act as a "Pure Hinge" (1924) or Fulcrum for the first 20 mm of opening

CR inevitably starts their mechanical based argument over this idea and draws a very defined "line in the sand" for anyone who dares to challenge this age old theory

Does Posselt's Diagram of jaw movement hold up to the "common sense" idea of occlusion?

  • Introduced in 1952 as a way to explain "border movements" of the mandible. Used a McCollum Gnathograph developed in 1934
  • Essentially this diagram which showed pure translation before the condyle would rotate became the basis of CR and the rationale for explaining the jaw as having pure hinge movement (like a fulcrum)
  • So, why would we care? The CR camp cares because this helps them hold onto antiquated teachings and supports the idea of "bi-manual manipulation" of the jaw
  • According to the current definition of the Bimanual Manipulation Technique is: "a technique used by dentists to establish where the resting muscle position of the lower jaw is relative to the upper jaw." 

"Resting muscle position" of the lower jaw?

  • CR now recognizes that the original technique for the most superior and posterior position might impinge on retrodiscal tissue or pad.
  • So while Posselt's research was ground breaking in 1952 using technology from 1934 and based on a theory from 1924 it is simply antiquated and outdated in 2011
  • Journal of Oral Rehabilitation, 1996, June:23(6):401-8
  • Study done in Italy showed there was NO PURE rotation of the mandible, not even in the first millimeter of movement. Rotation and Translation were always present together. Study disproved McCollum's 1924 Hinge Axis Theory as well as Posselt's Envelope of Movement
  • In many ways the "common sense approach" to this whole issue or argument is simply that the so called "Fathers of Gnathology" were very brilliant and did much to elevate dental knowledge. However, their paradigm (and that of today's CR teachers) is based on explaining jaw movement in pure mechanical terms and is not relevant today.
  • With the advent of NMD and the advancements which have taken place over the past 40+ years we now can see that the movements of the mandible are more dictated by the musculature. 

So let's take a closer look at occlusion education

  • It is true that all dental schools in the US "teach" Centric Relation. However 90+% of all dentists walk out of school with a very rudimentary understanding of occlusion and do 100% of their dentistry in CO or Habitual Occlusion for the rest of their career
  • Why? What they were taught in school made no practical sense in real world dental practice so they scrapped it on DAY ONE! Many very successful NM dentists were trained after dental school in "advanced" CR techniques but found this philosophy did not always work for them. 
  • So that leaves perhaps 5-8% of dentists who took advanced training in CR after dental school (Pankey, Dawson, Kois, etc...). Many, if not most of these dentists are competent, caring and skilled practitioners who simply "don't know what they don't know." (IMHO)
  • There are MANY doctors who have converted from CR to NMD but I can't think of a single NM trained dentist who converted to CR 
  • How do they complete these large restorative cases and why are they sometimes successful?

How CR full mouth cases are done

  • First, most of these folks have never even completed a 28 unit dental case of a mutilated dentition 
  • They NEVER do both arches at one time. Why? Because they don't know where the bite is (NM Physiologic Rest)
  • Labs almost always have to "open the pin" on the articulator because the collapsed bites they are given don't allow for correct aesthetic length and width ratio of the teeth
  • Obviously this is not accurate, so what do you do then?
  • The cases are sent back to the dentist unfinished (bis-baked) so the restorations can be seated and adjusted, then sent back to the ceramist for completion....hmmmm
  • The lower arch is prepared in much the same way until the CR dentist believes they have captured the bite and the case is finished and delivered
  • This DOES WORK in many situations because of the human body's amazing ability to accommodate and when the goal posts are WIDE ENOUGH
  • What happens when they are not?*

Compare to NM Full Mouth Case (technique taught at LVI during the Core VII course)

  • Phase I treatment after bite is taken. Usually patient is started in removable orthotic but not always
  • Bite is refined with use of objective data from K7 and patient (are muscles truly in an optimum position)
  • Case is moved to a fixed orthotic for additional refinement of the bite and then accurately transferred before case is prepared
  • Prep day: bite is sacred and attention to detail insures it is not lost
  • Lab is able to build 28 units at this exact bite position so the porcelain units can be delivered in one appointment at the correct bite position
  • Use of NM instrumentation allows for accurate micro-adjustments over the next several weeks until patient is completely comfortable.
  • If you have not been to Core VII yet or it has been a few years, you need to go. It is almost uncanny how smooth the whole process has become!*

Another Mechanical Based Myth about NMD

Canine Guided (protected) Occlusion is not built into the cases

So where did "canine guided" occlusion come from in the first place and how is it addressed by NM dentists

  • In many ways NMD pays little to no attention to Canine Guided or Protected Occlusion. It is however often times built into our cases, especially when we request our labs to do so...more for aesthetics than function!
  • This was ALSO the case with all of the early gnathologists until the 1960s when Stuart, Stallard and McCollum began to abandon group function
  • Cuspid Protected Occlusion as it was described by D'Amico does not even show up in the dental literature until he published his paper on the topic in 1958
  • It is very important to understand that this theory, no matter how widespread within the dental profession, has never been universally accepted or scientifically proven.*
  • The essential rationale for Canine Guidance is that the front teeth are farther from the fulcrum of the TMJ and therefore at a more favorable mechanical advantage to protect the posterior teeth....hmmm
  • Scan 8 (Chewing Cycle) clearly demonstrates the human chewing stroke. What this reveals is a fascinating look at how the muscles clearly guide the mandible out of Habitual Occlusion and then back to a definite point without ever even touchingthe cuspal inclines of the teeth
  • A skilled ceramist will actually use a preoperative Scan 8 to know how to develop the cuspal inclines of the restorations (steep vs. flat inclines)
  • In conclusion, the "common sense" argument is that there is really nothing to discuss and we should move on to more important topics! Teethhave shapes to allow the muscle proprioception to "guide" the teeth into a home position and improve the efficiency of mastication.

Airway is King!!! The Evolution of NMD

We can now see that most everything that was being discovered and discussed concerning NMD was occurring because of the airway!

Evolution is Knowledge and Understanding of Airways

  • Dr. Westin Price (1870-1948). Dentist from Cleveland known as the "Charles Darwin of Nutrition"
  • In the 1920s he began to notice patients with narrow faces, underdeveloped mandibles, forward head and neck posture, and crowded dentitions
  • Traveled each summer to study primitive and isolated cultures
  • Found cultures without "modern diets" such as processed sugar & flour, pasteurized milk and canned foods had "beautiful, straight teeth"
  • These same cultures when they adopted so called modern diets would have crowded dental arches within one generation

The Industrial Revolution

  • Development of global man-made pollution
  • The industrial Revolution: generally considered the 200 years of the 18th and 19th centuries
  • Wiki: time of major changes in agriculture, manufacturing, mining, transportation, and technology
  • The Industrial Revolution resulted in massive pollution of the air, water and soil
  • Harmful human generated waste has increased astronomically and changed the planet forever 
  • Poly-Aromatic Hydrocarbons are pollutants produced as byproducts of fuel burning items such as coal, tar, oil, wood and tobacco. They have been identified as being carcinogenic, mutagenic (capable of inducing genetic mutation), and teratogenic (able to disturb the development of the embryo or fetus)

What does the Industrial Revolution, Dr. Westin Price, processed foods, and pollution have to do with NMD?  Everything!!!

  • Remember Dr. Jim Garry who passed away in 2004? 
  • "Pedodontist, Neuromuscular Dentist, Airway Specialist"
  • Understood that airway obstruction effected the growth and development of not only the arches but the entire body!
  • Dr. Garry observed that after simple removal of the tonsils and adenoids the dental arches would begin to develop normally even without orthodontic intervention*
  • Additionally, in many cases the children would no longer suffer fromconditions such as ADHD, autism, chronic allergies and asthma
  • The human body needs oxygen to not only grow and develop but also to survive and Dr. Garry saw the relationship associated with these allergies to things like cows milk
  • Today we know there are other extremely common allergens such as Wheat Gluten. WHO, based on research at the Mayo Clinic found that intolerance is at least four times higher than just 50 years ago.

Obstructive Sleep Apnea!

  • According to the NIH 18+ million Americans suffer from OSA
  • The vast majority of these cases are undiagnosed
  • Most if not all OSA patients experience night clenching/bruxing
  • The relationship between OSA and sleep clenching is believed to be related to the arousal response at the end of an apnic event
  • Bruxing and airway appear to be associated with the patient's attempt to develop a patent airway during a desaturation episode (Apparently Dr. Glassman was refuting this at the last Sleep Dentistry Conference. Personally I feel the evidence is overwhelming in support of the bruxing/airway link)
  • I remember Dr. J would say that NMD would correct bruxing but he believed clenching was more of a CNS issue. Today we understand this probably to be more of an unresolved OSA issue

What Neuromuscular Signs and Symptoms Develop When There is an Airway Problem?

  • Crowding of the lower anterior teeth
  • Bicuspid drop-off
  • Deep curve of Spee
  • Deep bite
  • Cross bites
  • Lingually inclined teeth
  • High vaulted palates
  • Narrow dental arches
  • Clicking and popping TM joints
  • Ear congestion
  • Headaches
  • Forward head and neck posture, etc...

Why do so many dental problems result when there is an airway problem?  Let's look at the research. 

  • 1952: Balters states the tongue is the essential factor for the development of the dentition. "The equilibrium between tongue and circumoral muscles is responsible for the shape of the dental arches..."
  • 1963: Bosma noted that pharyngeal airway maintenance is the principal determinant of the AP relationship between the tongue and incisors
  • 1970: Genisor described how the tongue would be held in an altered posture to maintain airway even if there was a slight alteration in the respiratory system
  • 1984: Solow et al. Looked at the association between airway obstruction by the adenoids and craniofacial morphology
  • 1986: Santamaria, Lowe, Fleetham, and Price quantified facial morphology associated with OSA. There subjects showed all of the same problems we commonly associate with TMD....hmmmm?
  • 1991: Woodside studied the amount of maxillary and mandibular growth after removal of the adenoids which of course showed to be increased (Dr. Garry had unofficially already done this study more than 20 years before!) 

So what is the common sense connection?

Tongue and arch development recap

  • Very common for child to be allergic to either their environment or diet (both?) in today's world
  • As a result the tonsils and adenoids are enlarged and the airway is compromised
  • This results in altered tongue position to maintain a patent airway (we need air to survive so body must accommodate)
  • A whole host of problems develops. (See NM Signs and Symptoms). Many of these are symptoms patients would not normally inform their DENTIST of having!
  • As an adult there are problems with OSA, bruxing, mutilated dentitions, crowded teeth, TMD/CMD issues, etc...
  • These people are seen EVERY DAY in our offices. Very few dentists have the knowledge of how these NM problems develop and even less understanding of how to treat them.

The Dreadful NM Dentistry Story

  • I know the story of this kid who was born way back in 1966 in the United States
  • He was fed well but often times with way too many processed foods which had become common during the 1970s and 1980s
  • He loved dairy and drank tons of milk. He has never been diagnosed with any food allergies or even a food intolerance
  • His dentist growing up was very old and a family friend. This dentist never referred him to the orthodontist at a young age to address crowded teeth
  • Never had tonsils and adenoids removed as there were not enough "sore throats" to be considered for this type of procedure by the local MD
  • He was eventually referred to orthodontist in high school after the old dentist passed away and the family began seeing a young "modern" dentistOrthodontist was well intentioned and in fact president of the state orthodontic he must of been really good!
  • Treatment was for immediate extraction of four premolar teeth because his teeth were simply "too big for his mouth "
  • Eventually all of his third molars were also extracted 
  • High-pull headgear was utilized to further retract the dentition up and back. No expansion was ever utilized
  • Second orthodontic phase completed in college to finish case and correct relapse (total of 5 years in active orthodontics)
  • Overall, all this time with dentists and in orthodontics to some degree influenced this young college kid and helped him consider the field of dentistry as a career
  • He did in fact go on to dental school at the University of North Carolina and after graduation started a private practice at the ripe old age of 25
  • Having another "well intentioned" orthodontist practicing across the street it would not have been uncommon to see children referred to this young dentist to "pull the 1st premolars" in order tomake room for teeth
  • Not knowing any better, he would blindly do what he was told and never ask a question as to why this needed to be done or if there were options
  • During his first five years in office several patients were sent to have the local oral surgeon perform surgeries on the TM joints 
  • Most if not all TMD/CMD patients in the office were referred to one of these two esteemed "specialists" because this was what he was taught to do in dental school
  • Some Pankey/Dawson courses were taken but they never really made sense so pain patients were basically ignored and not treated
  • Finally, as many or more likely most of these people never really got better they were all deemed to simply be too stressed in their lives or simply "crazy" and their TMD problems were never discussed again

Let's look at our orthodontic patient/dentist at age 45. Does anyone think he became a NM Nightmare?

  • Forward head posture
  • Very small dental arches (look more like the arches of a child) resulting in unaesthetic narrow smile with high vaulted palate
  • Occasional facial muscle pain, especially in the masseters. This can actually be quite severe
  • Unable to chew hard foods or gum for long periods without discomfort 
  • Neck and back pain which gets worse as the years go by
  • Moderate OSA issues, especially if sleeping supine. Was a subject in Sam's NMD sleep study last year that was presented during the IACA meeting in Boston
  • Wears a SomnoDent Appliance to correct
  • Exostosis (buccal) and gingival recession. Extensive periodontal grafting completed in late 20s
  • Unexplained RCT #9 (#21 Universal)
  • Locked in buccal cusps of lower arch
  • Generally a NMD nightmare!
  • Getting ready to attempt expansion in order to gain lost premolars back and replace with implants

Is this a classic NMD scenario we see in our dental offices virtually every single day?

  • Could this have been prevented? Dr. J had invented the Myomonitor 2 years before he was born. At the time of the orthodontics many cases were being set up with the K6i
  • Can NMD help this person today, even at age 45? I would like to think so
  • Could addressing the OSA possibly allow this person to live a longer life so he could see his grandchildren one day?
  • Is this the type of dentist or dental team member you want to become?
  • NMD is MUCH more than creating beautiful smiles and "cosmetic" dentistry. It truly is about becoming a physician of the mouth and a life-long learner to explore the "rabbit-hole"*

I  want to extend a special thank you to Dr. Mark Tompkins for keeping me on track and proofing this presentation. Without his help I might have never even put this lecture together!