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Misconceptions, Facts and Truth

The problem with trying to discuss this evidence and show peer reviewed literature is that there is overwhelming literature that has been presented to both the ADA, FDA and to congress that has convinced even the most skeptical Advisory Panels that the neuromuscular approach using computerized diagnostic and treatment instrumentation (Myotronics, K7) is absolutely scientific and valid. Neuromuscular dentistry and its use of bio instrumentation is sound and has faced the most scrutinizing of tests.


1. CRITICS SAY: “The concept of neuromuscular dentistry implies that TMJ problems are due to a muscle problem related to neurological dysfunction. The concept has no scientific literature to support the claims and in fact. Most of the support for their claims is based on case‐based observation. Scientific inquiry using control groups versus patient groups have not shown a link either to jaw position or to malocclusion. Costen described TMJ disorders in the dental literature in the 1930’s and linked them to a collapsed bite. He developed a treatment using a removable appliance that opened the collapsed vertical and found that the patients benefited from the treatment. From that time until the 1960’s, dentistry incorporated the idea of decreased vertical dimension as the cause of TMD.”

Neuromuscular dentistry approach does not stand on implications about what TMJ problems involve as the critics would like sway the lay public and dental profession to believe, but rather the neuromuscular approach recognizes TMJ problems are multifaceted in nature involving a multi etiologic group of problems that involve both medical as well as dental conditions relating to the temporomandibular joint, muscles of mastication, the teeth/occlusion as well as the central nervous system.  Literature reports to the contrary of the critics opinion clearly shows that major part of TMJ/TMD symptoms are related to muscle hypertension and malocclusion problems. A number of studies have substantiated an association between dental occlusion and TMD.  These studies have documented the role of occlusion as a predisposing, initiating and/or perpetuating factor in the etiology of TMD.  What  the critics have fail to indicate and or willing want to ignore is that fact that there is significant scientific literature to support a clear connection between occlusion and TMD.

  1. Kirveskari P, Alanen P, Jämsä T: Association between craniomandibular disorders and occlusal interferences. J Prosthet Dent 1989; 62(1):66-69.
  2. Kirveskari P, LeBell Y, Salonen M, Forssell H, Grans L: Effect of elimination of occlusal interferences on signs and symptoms of craniomandibular disorder in young adults. J Oral Rehabil 1989; 16 (1):21-26. 
  3. Fushima K, Akimoto S, Takamot K, Kamei T, Sato S, Suzuki Y: Incidence of temporomandibular joint disorders in patients with malocclusion. Nihon Ago Kansetsu Gakkai Zasshi 1989; 1(1):40-50. 
  4. Raustia AM, Pirttiniemi PM, Pyhtinen J: Correlation of occlusal factors and condyle position asymmetry with signs and symptoms of temporomandibular disorders in young adults. J Craniomandib Pract 1995; 13(3):152-156.
  5. Raustia AM, Pyhtinen J, Tervonen O: Clinical and MRI findings of the temporomandibular joint in relation to occlusion in young adults. J Craniomandib Pract 1995; 13(2):99-104. 
  6. Liu JK, Tsai MY: Association of functional malocclusion with temporomandibular disorders in orthodontic patients prior to treatment. Funct Orthod 1998; 15(3):17-20.
  7. Kirveskari P, Jämsä T, Alanen P: Occlusal adjustment and the incidence of demand for temporomandibular disorder treatment. J Prosthet Dent 1998; 79(4):433-438.
  8. Mao Y, Duan XH: Attitude of Chinese orthodontists towards the relationship between orthodontic treatment and temporomandibular disorders. Int Dent J 2001; 51(4):277-281. 
  9. Sonnesen L, Bakke M, Solow B: Malocclusion traits and symptoms and signs of temporomandibular disorders in children with severe malocclusion. Eur J Orthod 1998; 20(5):543-559. 
  10. Çeliç R, Kraljevic K, Kraljevic S, Badel T, Panduric J: The correlation between temporomandibular disorders and morphological occlusion. Acta Stomatologica Croatica 2000; 34(1). 
  11. Kirveskari P, Alanen P, Jämsä T: Association between craniomandibular disorders and occlusal interferences in children. J Prosthet Dent 1992; 67(5):692-696.
  12. Fushima K, Inui M, Sato S: Dental asymmetry in temporomandibular disorders. J Oral Rehabil 1999; 26(9):752-756. 
  13. Kloprogge MJ, van Griethuysen AM:Disturbances in the contraction and co-ordination pattern of the masticatory muscles due to dental restorations. An electromyographic study. J Oral Rehabil 1976 3(3):207-216.
  14. Beitollahi JM, Mansourian A, Bozorgi Y, Farrokhnia T, Manavi A: Evaluating the most common etiologic factors in patients with temporomandibular disorders: A case control study. J Applied Sciences 2008; 8(24):4702- 4705.
  15. Purisa Cholasueksa, DDSa; Hiroyuki Warita, DDS, PhDb; Kunimichi Soma, DDS, PhDc.: Alterations of the Rat Temporomandibular Joint in Functionalv Posterior Displacement of the Mandible. Angle Orthod 2004;74:677–683. Functional malocclusion that induces condylar displacement that may effect the remodeling process of the temporomandibular joint structures). 

The neuromuscular concepts are based on objectively measured evidence founded on generic bio-physiologic laws of muscle function and resting modes that can be correlated to an optimal physiologic position of the temporomandibular joint and occlusion (the bite).  It is these concepts that are inherent in the field of physical medicine and dentistry involving the structural alignment of the head, neck, shoulders, pelvis, legs and including the cranio to mandibular relationships that encompasses this study and discpline of these interrelated entities that is included in the subject called neuromuscular dentistry. 

Read more:  “Is Occlusion a Primary Cause of TMD”?

Neuromuscular dentistry (NMD) is a discipline of dentistry which recognizes that nerves (neural) and muscles (masticatory system) are a significant component to the Trigeminal system. It recognizes the biophysiologic sciences relating dental patho-physiology, and their relationship to masticatory muscles dysfunction and joint dearrangment problems through the neural pathways relating to the central nervous system.

The Nuprin Pain Report by Louise Harris Associates reported:

■ “Some feel that 70-80% of those with headaches have significant “muscles of mastication component” that are often undiagnosed and untreated.
■ That compares with 15,100,000 workdays lost due to dental pain.
■ Over 30% of all work days lost is reported in the study may have a dental component (including the muscles of mastication).

Every clinician who practices and treats TMD cranio-mandibular/ cervical disorders of various complexities realizes that there are millions of people seeking answers to their problems. Each dental practice is an environment for controlled studies testing academic paradigms to validate whether what is stated in the literature is true or not.

Neuromuscular dentistry is founded on scientific literature both in the medical and dental  to support these concepts and principles. NMD recognizes that there are numerous musculoskeletal occlusal intra as well as extra oral signs that effect the central nervous system. It is the array of these multi-faceted problems that often go unrecognized by practitioners, but are very apparent once one investigates the etiologies and sources to these musculoskeletal occlusal problems. Many consumer patients report TMD and cranio facial symptoms relating to occlusal disorders.

The 1973 Noble Prize winning Dr. Aelred Fonder, B.A., D.D.S., F.R.S.H., research in medicine and physiology relating to dental distress syndrome findings affecting dentistry and dental attitudes presented the Alexander therapy that normalized body posture through gentle muscle manipulations that corresponded to spinal posture normalization by elimination of masticatory muscle imbalances. He reported through normalization, physical and mental health problems are resolved.  All systems of the biologic unit are effected by the bodies posture.

  1. Tinbergen, Nikolass: Etheology and Stress Diseases. (Noble lecture. Sweden, Dec. 12, 1973) Amer. Assoc. for Advancement of Sc., 185:20, July, 1974.
  2. Alexander, FM.: The Use of Self, Chaterston, London, 1932.
  3. Barlow, W.: The Alexander Principle, Gallancz, London, 1973.
  4. …..: op. cit.
  5. Dewey, J.: The Use of Self by Alexander, Chaterston, London, 1932.
  6. Huxley, Aldous: Ends and Means, Chattto and Windus, London, 1937.
  7. Coghill, G.E.: Appreciation: The educational methods of F. Mathias Alexander in F.M. Alexander, The Universal Constant in Living. Dutton, New ork, 1971.
  8. Dart, R. A.: S. Afr. Med. J. 21:74, 1974; An Anatomist’s Tribute to F.M. Alexander, Sheildrake Press, London, 1970.
  9. Sherrington, C.S.: The endeavor of Jean Fernel. Cambridge Univ. Press, London, 1946: Man and His Nature. Cambridge Univ. Press, London, 1951.

Clinicians as well as TMJ patients are looking for real answers to their headaches, facial pain, ear congestion problems, eye pressure pain, clicking and popping joints, shoulder pain, ringing in the ears, restricted jaws, numb hands and tinging fingers and more. The consumer as well as dental practitioner are looking for logical answers realizing that the medical and academic dental community have failed to acknowledge and recognize that these pain problems are related masticatory dysfunction and joint dearrangement problems.

The neuromuscular approach recognizes that establishing homeostasis of the masticatory, joint and cervical system is a foundational principles that goes hand in hand with biophysiologic health. Clinicians around the world have recognized that there are logical answers to these problems and patients are testifying that there is light at the end of the tunnel.

Based on Costens observations, is it possible that the loss of vertical dimension in the occlusion/bite contribute to masticatory muscle dysfunction (hypertension) and TMD symptoms may be due to a lack of physiologic occlusal and muscle balance between the cranium, mandibule and cervical/neck regions?

The scientific literature reports increased TMD symptoms when occlusal interferences are present.  If occlusal interferences are removed and TMD symptoms diminish does this mean that teeth play a part of the role in either increasing or decreasing TMD symptoms? 

Teeth, the muscles of mastication and temporomandibular joints are innervated neurally via the trigeminal systems (v1, v2 and v3).  Proprioceptive fibers go to the sensory and spinal nucleus of the Trigeminal nerve linking the Trigeminal spinal nucleus (perception of pain, temperature and tactile senses) with the Trigeminal sensory nucleus (discrimination of touch to face) and the Mesencephalic Trigeminal nucleus (reflex and control) through the medula, cerebellum and midbrain. 

How do critics of NMD justify and support their position of the TMJ problem?  Is it a muscle related problem, a neuralogical dysfunction or a combination of both? 

It is clear that the critics cannot scientifically substantiate their position, but to only further their opinionated perspectives within the dental ranks with no bio-physiologic and neuro-physiologic scientific foundation to their confusion.  They feel threatened by the overwhelming evidence of science and want people to believe there is no science when in fact they have no scientific literature to prove otherwise.

Further Literature Search On:

  • Vertical dimension and pain
  • Vertical dimension and trigger points
  • Vertical dimension and neuralgia
  • Vertical dimension and hypoxia
  • A search and literature query regarding the connection between jaw positioning, malocclusion and TMJ and any controlled studies between control groups versus patient groups.


“Neuromuscular Dentistry (NMD) has consistently associated tension‐type headaches with muscle contraction due to improper jaw alignment and malocclusion. However, EMG studies looking at muscle contraction in headache patients have not shown a relationship. Current concepts of the neurophysiology of headache  that has been elucidated in controlled studies link headache not to muscle contraction but to a neurosensory disorder of the muscles. In a matched controlled study by Clark and and Sakai (Clark, G. T., S. Sakai, et al. (1995). “Cross‐correlation between stress, pain, physical activity, and temporalis muscle EMG in tension‐type headache.” Cephalalgia 15(6): 511‐8), there was not statistically significant relationship between headache and muscle activity. These results have been confirmed in numerous studies.”

There is a broad body of literature that supports the physiologic basis for using surface EMG (sEMG) in dentistry as an aid in assessment of muscle function and dysfunction. (38+ studies  support this ending with Lynn et al, 1992). 

• There is substantial evidence based upon controlled studies that confirm that surface EMG is reliable and reproducible. (18 studies ending with Dean et al., 1992).
• 87 studies verifying the use, safety, and efficacy of EMG to monitor masticatory muscle function/ dysfunction.

Surface electromyography has long been the “gold standard” for monitoring muscle activity of masticatory muscle at REST and in FUNCTION. The value of surface EMG is best expressed by C.J.DeLuca, Professor of Biomedical Engineering and Research and Professor of Neurology at Boston University, “Surface EMG utilizes sensing electrodes placed on the skin, which allows the clinician to directly and accurately monitor muscle activity. This is far more accurate procedure than conventional manual palpation or touch which can provide only gross assessments of muscle activity.” 1988. W.D.McCall also states “… there is general agreement among both clinicians and investigators that masticatory muscle activity is increased in symptomatic patients as compared with normal subjects. Electromyography is the principal tool used to investigate such differences.” (The Musculature. A Textbook of Occlusion, Quintessence, 1988). There is a broad body of literature that supports the physiologic basis for using surface EMG as an aid in assessment of muscle function/ dysfunction. (Moyer, 1949; Lippold, 1952; Perry, 1954; Bigland and Lippold, 1954; Jarabak, 1956; Perry, 1957; Porrit, 1960; Grossman, 1961; Moss and Greenfield, 1965; Moller, 1976; Mitani et al., 1972; Moss and Chalmers, 1974; Moller, 1975; Yemm, 1976; Milner-Brown and Stein, 1975; Pruim et al., 1978; Bakke et al., 1980 Riise et al., 1982; Sheikholeslam et al., 1982; Sheikholeslam et al., 1983 Riise et al., 1984; Algren et al., 1985; Kyslinski et al., 1985; Sherman, 1985; Goldensohn, 1986; Hermans et al., 1986; Kydd et al., 1986; Sheikholeslam et al., 1986; Balciunas et al., 1987, Burdette and Gale, 1987; Wood, 1987; Crain and Clemons, 1988; Chong-Shan and Hui-yun, 1989; Christensen, 1989; Koole et al.; Neil etal., 1989; Van Eijen et al., 1990; Jankelson, 1992; Lynn et al, 1992). While the skeptics would like to dimension the value, reliability and credibility of the use of sEMGs in clinical dentistry it is apparent that objectively measuring muscle responses under various conditions such as migraine, tension type headaches vs. controls can lead clinicians to conclude otherwise if they are not familiar with the various muscle activities conditions of individuals who experience myogenous facial pain vs. individuals who experience stressed induced migrainous tension type headache pain.  Surface EMG patterns will naturally be displayed differently (chronic fatigued typically displays lower EMG recordings) vs. non fatigued muscles display a more normalized EMG patterns).  sEMG recordings are clinically valid and requires a further analysis to properly distinction the difference between candidates who have muscle fatigued EMG patterns compared to those candidates who display non-muscle fatigued normalized patterns. Leistad RB, Sand T, Westgaard RH, Nilsen KB & Stovner LJ.reported in their article, “Stress-induced pain and muscle activity in patients with migraine and tension-type headache”. (Cephalalgia 2006; 26:64–73. London. ISSN 0333-1024), that EMG responses of migraineurs and patients with tension type headaches (TTH) were not different from the controlled headache patients, and EMG responses did not correlate with pain responses.  Based on this study the authors support the concept that “…(probably central) sensitization of pain pathways and the motor system is important in TTH. Less pronounced and more regional (either peripheral or central) trigeminocervical sensitization seems to be important in migraine. Surface-detectable muscular activation does not seem to be causal for pain during cognitivestress either in migraine or in TTH.” Fatigue has been defined as a decrease in force production or an inability to regenerate the original force in the presence of an increased perception of effort.”  Different types of muscle contraction EMG patterns will display different NM EMG fatigue profiles.  Eccentric activity is largely fatigue resistant, isometric  and concentric contractions displayed different NM fatigue Profiles.  (Kay D., St Clair Gibson A, Mitchell M.J., Lambert M.I., Noakes T.D..: J. Of Electromyography and Kinesiology 10(2000) 425-431).

Patients with fatigued muscles and compromised motor unit firing may exhibit variations in EMG readings especially in female CMD patients (Paesani et al.: Evaluation of the reproducibility of rest activity of the anterior temporal and masseter muscles in asymptomatic and symptomatic temporomandibular subjects, J Orofacial Pai 1994;8:402-406.) from session to session. They suggested that rest EMGs taken over a treatment period would not be reliable to evaluate the effects of treatment on chronic TMD patients. Thus the importance of assessing fatigue with mean spectral frquency analysis (Myotronics scan 18) to make the distinction. Observing lower then “normal” sEMG readings of resting muscles before and after muscle relaxion may possibly be those patients who have underlying fatigued muscles.


A typical skeletal striated muscle responds to a single adequate stimulus by giving a “twitch” which is a brief period of contraction followed by relaxation. The magnitude of the twitch response depends upon the strength of the stimulus. When that stimulus passes a threshold a small response occurs and progresses until the stimulus reaches maximal value. The response of individual muscle fibers is not graded which we know as the “all or none” principle that applies to single motor unit. Each masseter motor unit innervates approximately 600 individual muscle fibers all of which will respond when a threshold stimulus is applied to the motor nerve. However, the “all or none law” does not dictate that all responses must be of the same size, they may diminish in size as a result of fatigue or actually increase as result of a previous stimulation (facilitation).

If a second stimulus is given to the muscle before the response to the first stimulus has completely subsided, summation occurs. If stimuli are repeated regularly at enough frequency a smooth muscle tension develops as long as the train of stimulus continues. If the train of stimulus continues with increasing frequency fatigue may occur.

Muscle fatigue can occur because of either pre or post-synaptic mechanisms. Pre-synaptic fatigue can occur when the frequency of neural signalling causes depletion of myoneural transmitters such as acetylcholine, Ca++ etc. This fatigue is characterized by a shift of the EMG spectral frequency to the left — meaning the EMG signal frequency using Fast Fourier Analysis becomes less. This indicates a decreasing ability of the neural signal to cross the myoneural junction and depolarize the muscle fiber which results in the transmembrane excitable muscle fiber discharge detected by EMG signal. There are many studies using Fast Fourier Analysis supporting this fatigue phenomena.
 The post synaptic muscle fatigue mechanism involves depletion of muscle energy sources involved in the Krebs Cycle. Hydrolysis of ATP high energy molecules from glucose, O2, Ca++ etc., is necessary for efficient muscle function. Depletion of blood flow, loss of available oxygen and glucose then affects the ability of the myosin to bind at the actin tropomine binding site. This diminishes the actin/myosin contractile mechanism necessary for normal muscle function. Fatigue which is a loss of excitability may then be due to inadequate ATP to assure optimal contractile function.

Naturally, EMG studies looking at muscle contraction in headache patients have not shown a relationship since those studies were not evaluating or studying the fatigue phenomenon.  Cross correlation between stress, pain, physical activity, and temporalis muscle EMG in tension‐type headache studies were obviously not found to show statistical significant relationship between headache and muscle activity in the critiques reference studies since these studies did not further focus on distinguishing fatigue muscles from their controls.

The following list below is a partial list of the large body of supportive evidence documenting the use and efficacy of electromyography as applied in clinical dentistry.

Physiologic Basis for Using Quantitative EMG
There are numerous studies that support the physiologic basis for using quantitative electromyography in the diagnosis of temporomandibular and occlusal disorders (Moyers, 1949; Perry, 1954; Jarabak, 1956; Perry, 1957; Porritt, 1960; Grossman, 1961; Moller, 1966; Yemm, 1976; Bakke et al., 1980; Riise et al,, 1982; Sheikholeslam et al., 1983; Riise et al., 1984; Kydd et al., 1986).

Surface EMG is Reliable and Reproducible
There is evidence, based on controlled studies that used extensive statistical tests, that surface electromyography is reliable and reporducible (Goldensohn, 1966; Lloyd, 1971; Mitani and Yamashita, 1978; Riise, 1983; Hermens et al., 1986; Burdette adn Gale, 1987).

Relationship Between EMG and Muscular Force
Controlled studies that used extensive statistical tests show that there is a strong relationship between EMG and muscular force (Lippold, 1952; Bigland et al., 1954; Molin, 1972; Milner-Brown, 1975; Pruim, 1978).

EMG Studies of Postural Rest and Maximal Bite Position
Several studies have quantitatively investigated the EMG during postural activity of the mandible and during maximal bite in the intercuspal position. The EMG values for the temporal and masseteric muscles have been quantitatively investigated in these studdies for control subjects without functional disorders and for patients with functional disorders. (Lous et al., 1970; Moller et., 1971; Sheikholeslam et al., 1980; Sheikholeslam et al., 1982; Moller et al., 1982; Cram and Engstrom, 1986). Thsese studies replicated the results that quantified statistically significant differences between the normal population and the patient population. The slight variability among these studies was due to the type of EMG instrumentation used in each study (i.e. range of filter frequency).

EMG Studies of Bite Force in Patients with Functional Disorders
There is evidence based on controlled studies that used extensive statistical test that maximal bite force and the electrical muscle activity during maximal bite in the intercuspal position are significantly weaker in patients with functional disorders of the masticatory system than controls without such disorders (Molin, 1972; Helkimo et al., 1975; Randow et al., 1976; Sheikholeslam et al., 1980; Moller et al., 1982; Sheikholeslam et al., 1982; Kydd et al., 1986.)

EMG Postural Studies of Temporalis and Masseter Muscle Activity
Controlled studies that used extenisve statistical tests conclude that postural activity of temporalis and masseter muscles are significantly higher in patients with functional disorders of the masticatory system thncontrols without such disorders (Moller, 1966; Lous et al., 1970; Moller et al., 1971; Sheikholeslam et al., 1982; Pantaleo et al., 1983; Geraris et al., 1989.)

EMG is Effective in the Diagnosis of Myofacial Pain
Clinical studies investigating Electromyography of temporal and masseteric muscles concluded that EMG was effective in the diagnosis of Myofacial Pain Disorders (Sheikholeslam et al., 1986; Pantaleo et al., 1983; Cooper et al., 1986; Moller, 1969; Hlekimo et al., 1975; Mylinski et al., 1985; Riise et al., 1982; Sheikholeslam et al., 1983; Riise et al., 1984.) These studies further validate the basis for the use of EMG in clinical dentistry. The patients examined in the above studies exhibited high levels of EMG postural activity and weak EMG activity during maximal bite in the intercuspal position. Occlusal therapy resulted insignificant improvement in symptoms and pain , and the successfully treated patiens had significantly lower postural activity and significantly improved and symmetrical maximal bite activity.

In summary, based on well controlled empirical and clincal studies that have been conducted in several universities over the past three decades thoughout the world, there is unequivocal evidence to strongly support the use of EMG for the evaluation and diagnosis of temporomandibular joint and occlusal disorders.


“The claims of NMD run counter to medical science and are unproven in their own literature. There are no supportive studies showing these claims to be true. The usual documentation provided comes from case reports of successes but not from placebo controlled studies. A huge problem with these claims is that they run counter to accepted medical knowledge often overlook serious medical problems that may be the basis for the headache and pain problems the patient is experiencing. For example, treating a headache with jaw repositioning, assuming that the bite is the problem can have a catastrophic result if the headache is due to a brain tumor or aneurysm. The NMD does not follow accepted and required medical assessment of the disorders alluded to in the above statements but proceeds with treatment based on the assumption that the problems are due to jaw misalignment and bite discrepancies. This is medically and legally irresponsible.”

The claims that neuromuscular dentistry runs counter to medical science is unfounded and false.  In fact, NMD follows very conservative protocols that are in line with today’s medical and dental science and clinical guidelines.  It encourages a comprehensive evaluation not only of the patient’s history , physical assessment , psychosocial cursory evaluation, and a pharmacological assessment, but additionally an evaluation of the patient’s physiologic resting and functional body responses that go beyond subjective complaints.  This approach is well within the scope of medical care guidelines.

NM instrumentation is used to objectively record and measure the patient’s physiologic responses to quantify and validate patients  complaints and supplement doctor’s subjective assessment.  Documenting and recording objectively and gathering data is prudent protocol for any clinician or academic who is serious in researching and discovering physiologic truths in patient care and management. Those anti-instrumentation advocates who continue to criticize and misinform the public and dental profession about neuromuscular dentistry are fearful that the validity of objective analysis will bring to light significant truths about TMD issues and how it is connected to occlusion causing these skeptics to return to key clinical principles that are requisite requirements that they fail to implement in their clinical TMD practice.  Objective measured data doesn’t lie, neither is it forgiving when it holds the treating clinicians to a higher standard in occlusal treatment.  Those who don’t believe that occlusion is related to TMD issues naturally rather stay sloppy and casual in their methodologies and interpretation of the patients subjective complaints.

Gathering objective real time data precludes a treating clinicians bias and subjective assumptions.  The NMD approaches fundamental aim is to remove clinicians bias whichis counter to the misleading statements of our critiques who don’t use these kind of technologies.  For this reason, those clinicians who implement the NMD approach don’t understand why these critiques would make such outlandish and false statements.  No prudent clinician desires to overlook serious medical problems and or wants to assume that all headaches or pain problems stem only from a bite or TMD problems.  These statements from these critiques further expose their lack of understanding of NMD and the usefulness of measuring technology.

Further Literature Search on:

  • Differential diagnosis
  • Clinical exam techniques
  • Craniofacial conditions that mimic TMD 
  • Cause of craniofacial pain.

“A study done at UCLA found in 29 Controls and 29 Symptomatic Patients, both controls and
symptomatic subjects had deflective or interceptive occlusal contacts in terminal hinge closure and similar mandibular shifts from centric relation to centric occlusion. Significance: If occlusal interferences are similar in controls and patients, they may not be important in development of TMD.

Droukas et al., 1984 reported in a study of 23 women and 25 men with mean age of 25, that ideal occlusion was rare, the frequency of interferences was high and did not coincide with functional disturbances. In summary: Occlusal factors are generally not important.  7 Year Follow up Study by Mejersjo and Carlsson, 1983 found that in a 7 year follow up study of 154 Women who had been treated with conservative reversible treatment that:

84% reported that symptoms reduced.
80% had few or no symptoms.
20% had recurrence of some symptoms
14% had had to return for more treatment.”

Such studies done are not done with an objective unbiased approach to their methodology of research, but rather they put for a biased assumption and try to validate their opinionated views in the name of a “study”.  Thus, a faulty train of thought and reasoning to make such weak connection between occlusal interferences, symptoms and controls.  What they failed to consider is different individuals and age groups can also have various levels of adaptive accommodative capacity or resistance levels of health even though they may have occlusal interferences with no symptoms.  This group could have what some consider a wide accommodative capacity.  While there is a population group that have rather low levels of resistance or narrow accommodative capacity and experience significant discomfort, TM joint pain leading to masticatory muscle dsyfunction and joint derangement problems. Those who treat pain patients recognize these clinical realities to which these critics fail to acknowledge, thus they draw wrong conclusions.  To say occlusal factors are general not important is to ignore significant factors of the masticatory system and to only partially treat the problems and not the whole issue of TMD which is a multi-factorial issue comprising the enter relationships between the teeth/occlusion, temporomandibular joints and the muscles of mastication which also includes the cervical muscles which supports the posture of the head and neck.  To ignore occlusion and conclude that TMD is not related or has no significance to TMD is neglectful and a faulty line of thinking.

Certainly, the neuromuscular approach believes in a conservative reversible methods, but also does not ignore the important role that occlusion plays in the bodies postural stability defense and functional mechanism.

“De Leeuw, R., Ed. (2008). Orofacial Pain; Guidelines for Assessment, Diagnosis, and Management. Hanover Park, Il, Quintessence Books.  Historically, occlusal guidance has been considered a significant factor in TMD.  Most studies have not shown evidence of this.  Historically, overbite has been associated with joint sounds and muscle tenderness.  Most studies do not support this association. Reduced overbite or anterior open bite has been associated with condylar changes and RhA. And this is supported in the literature.”

FACTS: There is a difference between academic theoretical understanding and clinical experiential understanding.  All those who practice comprehensive dentistry including prosthodontists realize that ignoring fundamental occlusal schemes which would including establishing a balanced terminal contact on a proper isotonic closure will in fact induce  muscles strains to the neuromuscular system along with contributing joint problems such as clicking or popping sounds in the TM joints.  Any posterior occlusal inferences has been shown to induce muscle, nerve and supporting bone irritations.  This has been recognized by anyone who has undergone restorative dentistry – fillings, crowns, and or and occlusal appliance treatment that was not properly balanced and equilibrated. It does take academic studies to prove this.  Every day people come to dental offices and if their new fillings or crowns are too high they will experience tooth pain, tooth aches as well as muscle aches (in certain instances, they can even experience headaches and neck pain).  Any normal human being can not be convinced that occlusion doesn’t contribute to the mentioned TMD symptoms and is a psychological phenomenon only.

Anterior open bites, lack of proper over-jet and overlap for some may not display immediate signs of occlusal or TMD issues, but in the long run they will since muscles, joints and teeth are designed to work in synchronous with one another. Anytime there is an imbalance of forces strain will occur and TMD issues begins to increase.  In certain cases an untrained dentist will not recognize the connection immediately, but to a trained clinician it is obvious. Prevention is the key.  Proper orthodontic tooth arrangements as established by natures design are designed to protect and support physiologic health and quality function.  Abnormal arrangement of teeth will in time lead to dysfunction and abnormal unhealth.

Clayton Dentistry

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