OBJECTIVE MEASURING TECHNOLOGIES: A Physiologic and Functional Bases to the Diagnosis and Treatment of TMD
Temporomandibular disorders (TMD) is defined as a group of clinical problems that involve the masticatory muscles, the tempormandibular joint (TMJ), and the associated structures.<1> The associated and supporting structures are the dentition and the neuromuscular system complex that are attached to the mastictory muscle system and the temporomandibular joint system. TMD can coexist with other musculoskeletal disorders within the head and neck area. A composite of different entities that relate to each individual TMD patient’s pain and physical dysfunction can also lead to manifestation of psychological stress. There are a number of varied signs and symptoms determined upon clinical examination that have been the subject of extensive research published in the medical and dental literature.<2>
There are some who skeptically believe and endorse a counter thought to the diagnosis and treatment of TMD. In a recent papers (March 11, 2013, Journal of Canadian Dental Association (JCDA): “How Effective Is the Neuromuscular Occlusion Approach in diagnosing and treating TMD?” based on the Rapid Response Report developed by the Canadian Agency for Drugs and Technologies in Health (CADTH): ” Neuromuscular Occlusion Concept-based Diagnosis and Treatment of Tempromandibular Joint Disorders: A Review of the Clinical Evidence stated on the JCDA blog page (http://www.jcdablogs.ca/2013/03/11/tmd/) the following misleading statement in their KEY MESSAGE:
- The use of electromyograms (EMG) is not supported by evidence. (FALSE AND MISLEADING)
- There is insufficient evidence to determine the diagnostic value of kinesiography. (FALSE AND MISLEADING)
- Electrical stimulation is not supported by evidence. (FALSE AND MISLEADING)
- The efficacy of occlusal splints is uncertain. (FALSE AND MISLEADING)
The JCDA further stated in their “Findings” section the following: “ Various studies related to the diagnostic values of the electromyography in TMD patients showed that the technology produced a wide range and inconsistent values of specificity and sensitivity that prevent its adoption as a diagnostic test for TMD. The EMG indices were not consistently different between TMD patients and the healthy controls. Furthermore, the EMG indices correlated poorly with the clinical signs and symptoms of TMD, such as pain and function. Other studies on the electrical stimulation of muscular muscles showed that the use of contingent electrical stimulation was not different from the use of placebo in changing the clinical outcome or the electromyographic evaluation.”
Again, these published statements are misleading and very incomplete in their investigative research. One has to question exactly what was this report trying to convey?
In this age of the internet where the general public are now developing a much higher dental IQ, it is the responsibility of each individual and overseeing dental organization to be very prudent in their publication of findings. Whether the JCDA blog intended it or not, people who read these messages would conclude that the neuromuscular approach is ineffective. Today clinicians are seeing patients who are benefiting from the Neuromuscular method. There will always be studies that will favor or refute the neuromuscular methods. The fact of the matter is that the causes of TMD are multi-factorial which is why there is no one mode of treatment that can claim 100% success. Success of treatment is based on the knowledge and expertise of each operator rather than the instrumentation used. Neuromuscular dentistry is conservative nature (reversible vs. irreversible procedures). Isn’t it time that regulatory agencies as the Canadian Agency for Drugs and Technologies in Health (CADTH) should re-examine the pre-defined inclusion criteria used in this “Rapid Response Report), reconsider its position statements as well as the intent of the authors who wrote this report.
To read other dentist outrage comments see: http://www.jcdablogs.ca/2013/03/11/tmd/
BEWARE OF ANTI OBJECTIVE MEASURING TECHNOLOGY DENTAL RESEARCH BIAS:
“Publication bias remains an area of contention amongst those who assess the quality of systematic reviews within the dental community. It remains a research priority because it is unclear what the impact of publication bias is on making decisions in health care. We are aware of the 20 years of work that has gone in this area of research. This has given us some clear answers as to the effect publication bias may have on the overall results of estimating the impact of interventions.”<5> A measurement tool for assessment of multiple systematic reviews (AMSTAR) was used as a tool for measuring the methodological quality of systematic reviews and content validity. Authors of AMSTAR too recognize that “Additional studies are needed with a focus on the reproducibility and construct validity of AMSTAR, before strong recommendations can be made on its use.”<5>
In this 37 page document presented to the CADTH it is evident that the drafters of this work clearly have done a lot of work, but the reviewers ‘ bias is quite evident. They have selected a group of references that lack many supportive studies. Two of the Cooper studies were included, but yet they rejected Cooper’s studies because it did not meet their selection criteria. They have violated their own tenet of “clinical evidence”, considering the conclusions that were reached in the Key Findings (page 2) “The use of electrical stimulation for the treatment of TMD is not supported by the current evidence”. They based their conclusions on two studies by Monaco, et. al. and Jadidi et. al.
With further more detailed analysis of what they are reporting, they violated their own tenet of “clinical evidence” and proper balance reporting by creatively and purposely eliminating what data and information they desire to report (cheering picking the literature) or construing as evidence to their summary findings based on their biased methods of ruling out what they feel is valid to convey their message – swaying the reader to conclude… “The diagnostic accuracy values of EMG were reported in two studies; both studies reported a wide range and inconsistency values.”
This type of academic literature research does not meet the criteria of presenting a balanced perspective of all the evidence on electromyography (EMG) use in clinical dentistry. Rather the researchers chose to bias their findings based conveniently on their own established terms of sensitivity and specificity.
In the Efficacy Studies section page 5, the reporters did not properly acknowledge the conclusions of the Monaco et al. study accurately or completely. It actually states: “Significant differences were only observed in the TENS group for masticatory muscles of both sides; one-way analysis of variance revealed that sEMG values of masticatory muscles of both sides in he TENS group were significantly reduced.”…but rather the researchers prefer to report: “….The evaluation was based on EMG and kineseographic indices without any clinical outcomes.” (The researchers did not disclose the actual effects of this 60 min. TENS application on sEMG and kinesiographic activity in this TMD patient study.)
Erroneous reporting was also evident where the researchers site the Jadidi et al study on page 7 in the Efficacy Studies section, but did not disclose this study used an “electrical square wave pulse train (450 ms)” biofeedback stimulator type unit rather than a low frequency TENS which is indicated specifically for relaxing muscles. It is not surprising that muscle tension was not reduced/relaxed using that kind of biofeedback modality in that study, thus the researchers are again cheering picking their literature studies to convey a wrong message about EMG and TENS efficacy and or the researchers are not clearly distinguishing the differences between electrical square wave pulse biofeedback stimulators vs. ultra low frequency TENS. They are not the same. It’s like comparing apples to oranges…thus their reported conclusions and results of this study are in question as to it’s reliability, sensitivity and specificity of their conclusions. This literature research study adds doubt and little confidence to the accuracy of this “Rapid Response Report”.
There are many TENS studies that they overlooked but the only study they produced that used a Myomonitor (Monaco’s study) indeed substantiates the efficacy of TENS in reducing muscle tension!!
RESEARCH QUESTIONS POSED:
1. What is the clinical evidence on the use of the neuromuscular occlusion (NMO) concept for diagnosis of temporomandibular joint (TMJ) disorders?
2. What is the clinical evidence of the effectiveness of occlusal adjustments, based on the neuromuscular occlusion concept, in treating TMJ disorders?
Clinical Evidence on the Use of Neuromuscular Occlusion for the Diagnosis and Treatment of TMD:
Scientific literature including the International Journal of Dental Research and the “Literature Review of Scientific Studies supports the Efficacy of Surface electromyography, Low Frequency TENS and Mandibular Tracking from Occlusion Evaluation and Aids in the Diagnosis and Treatment of TMD” by Jankelson RR and Adib F (2009) published by Myotronics Noramed, Inc. has presented sufficient data and science to confirm their clinical validity in dentistry.
- Known research findings on the effect of TENS on the electromyography frequency raw data (Thomas NR (1990), “Pathphysiology of Head and Neck Musculoskeletal Disorders: The effect of fatigue and TENS on the EMG mean power frequency” in Frontiers of Physiology vol 7:162-170 has been supported by a grant from MRC Canada and has been confirmed by Eble et. al. at Frieberg University Germany.
- The efficacy of electromyography in clinical dentistry has been clearly substantiated by numerous studies in the medical and dental literature. (For more references to scientific studies, See “The Efficacy of Electromyography in Clinical Dentistry”).
Monaco, A, et.al., in their study using 60 minutes of TENS application on surface electomyography (sEMG) and jaw tracking (kineseographic activity) in TMD patients in remission and to assess the sEMG and kinesiographic effect of TENS in placebo and untreated groups reported, “Significant differences were only observed in the TENS group, for masticatory muscles of both sides; one-way analysis of variance revealed that sEMG values of masticatory muscles of both sides in the TENS group were significantly reduced, in comparison with placebo and control groups.”….”TENS could be effective to reduce the sEMG activity of masticatory muscles and to improve the interocclusal distance of TMD patients in remission; the placebo effect seems not present in the TENS application.”<4>
There is sufficient supportive evidence showing efficacy for the use of Low Frequency Transcutaneous Neural Stimulation (TENS), Electromyography (EMG), Jaw Tracking (Kineseography) and Electrosonography (ESG) in the Diagnosis and Treatment of TMD:
Some reviewers have reached invalid conclusions regarding the value of surface EMG in evaluating TMD patients because EMG as a stand alone modality can not make a diagnosis i.e. rule-in or rule-out TMD. An EMG device does not make a diagnosis. Along with history, visual examination and imaging, the EMG data provide more knowledge for the dentist in making his or her diagnosis or evaluating treatment progress of a given patient. Despite the lack of the objectivity of these reviewers in their selection of 4 of the 6 studies they chose to investigated the EMG of masseter and temporalis muscles the studies concluded that “there was a statistically significant difference between TMD patients and a control group” further reinforcing the value of surface EMG as an aid in the evaluation of TMD patients, for planning effective treatment and for evaluating patients’ response to treatment. (This is what was not reported by these bias researchers.)
- Read more on the Efficacy of Surface Electromyography in Dentistry
With regards to the clinical efficacy of TMD treatment based on the electrical stimulation of muscular muscles, these researchers have tried to limit their study down to one randomized-controlled trial and two non-randomized trial. It is indeed very puzzling that with numerous studies of the efficacy of low frequency TENS that have been published (Wessberg et al, Boschiero et al, Konchak & Thomas, Eble et al, Weggen et al, Cooper), they only decided to select only 2. Regarding the Efficacy of TENS: The Reviewers exclude significant number of studies in support of the efficacy of TENS in treatment of TMD. Of the two studies that they include, one was irrelevant and the second study by Monaco et al, a placebo-controlled study, strongly supported the efficacy of TENS in reducing muscle tension and increasing vertical interocclusal distance. Therefore, the statements they try to promote and propogandize falsely reports that “The use of electrical stimulation for the treatment of TMD is not supported by the current evidence” is false and contrary to clinical evidence reported and documented in the Monaco et al’s study and many others.
- Read more on the Efficacy of Mandibular Tracking in the Diagnosis and Treatment of TMJ/MSD
- Read more on the Efficacy of Electrosonography (Spectral Analysis) in the Diagnosis and Treatment of TMJ/ MSD
Of the total of 596 articles that were identified by these reviewers, only one article was selected (Silva, et. al. ref. 28) page 5 of the CADTH report, to assess the efficacy of “occlusal splints prepared using the EMG values as a reference of ideal occlusion”. Silva et al’s study had a control group of asymptomatic subjects and concluded that “the use of the splint promoted balance of the EMG activities during its use, relieving symptoms. EMG parameters identified neuromuscular imbalance, and allowed an objective analysis of different phases of TMD treatment, differentiating individuals with TMD from the asymptomatic subjects”. Despite the authors findings and conclusions, the reviewers made this misleading statement in their report, stating, “No conclusions can be made on the efficacy of the occlusal splint on the neuromuscular occlusion concept” presumably because this study that strongly supports the use of an EMG derived occlusal splint did not use another “therapeutic modality” to treat a controlled group of patients.
(Related to the reviewers’ statements in the Key Findings and the Conclusions Sections of the CADTH Report): The conclusions reached by these reviewers can not be supported by the clinical evidence presented in the studies they selected for review.
Related to the whole body of medical/dental research articles: The conclusion reached by a manyof reviewers, academics and clinicians indicates a substantial body of scientific evidence supports the efficacy and use of electormyography, low frequency TENS, kineseographic (Jaw Tracking) and electrosonography for diagnosis of temporomandibular joint (TMJ) disorders.
1. de Felicio CmM, Ferreira CL, Medeiros AP, Rodrivues Da Silva MA, Tartaglia GM, Sforza C.: Electromyographic indices, orofacial myofunctional status and temporomandibular disorders severity: a correlation study. J Electromyogr Kineseol. 2012 Apr;22(2):266-72.
2. Cooper BC, Kleinberg I.: International College of Cranio-Mandibular Orthopedics (ICCMO). Temporomandibular disorders: a position paper of the International College of Cranio-Mandibular Orthopedics (ICCMO). Cranio. 2011 Jul;29(3):237-44.
3. Thomas NR: ”Pathphysiology of Head and Neck Musculoskeletal Disorders: The effect of fatigue and TENS on the EMG mean power frequency” in Frontiers of Physiology. 1990 Vol 7:162-170. (Norman Thomas, PHD; DDS:MB.BSC;FRCD; Certs Oral Path and Med; Med Ac(Alta) Professor Emeritus University of Alberta Canada).
4. Monaco, A, et.al.: Effects of transcutaneous electrical nervous stimulation on electromyographic and kinesiographic activity of patients with temporomandibular disorders: a placebo-controlled study”. J Electromyogr Kinesiol, 2012 Jun;22(3):463-8. DOI: 10.1016/j.jelekin.2011.12.008.Epub 2012 Jan 14.
5.Shea, BJ, et.al.:Development of AMSTAR: a measurement tool to assess the methodological quality of systematic reviews. BMC Med Res Methodol. 2007; 7: 10.Published online 2007 February 15. doi: 10.1186/1471-2288-7-10.