EMG feedback in the treatment of myofascial pain dysfunction syndrome

Myofascial Pain: Mechanisms to Management

More than 100 million adults in the United States have chronic pain conditions, costing more than $500 billion annually in medical care and lost productivity. They are the most common reason for seeking health care, for disability and addiction, and the highest driver of health care costs. Myofascial pain is the most common condition causing chronic pain and can be diagnosed through identifying clinical characteristics and muscle palpation. Management is focused on integrating patient training in changing lifestyle risk factors with evidence-based treatment. Understanding the cause, diagnosis, and management of myopain conditions will help prevent the impact of chronic pain.

Temporomandibular Disorder Diagnostic Groups Affect Outcomes Independently of Treatment in Patients at Risk for Developing Chronicity: A 2-Year Follow-Up Study

AIMS

To evaluate whether a biobehavioral intervention would be more effective than a self-care intervention or no intervention in reducing psychosocial distress, reducing pain, and improving functioning in patients with an acute myofascial temporomandibular disorder (m-TMD).

METHODS

Participants (n = 435) were from community dental clinics in the Dallas-Fort Worth Metroplex who were seeking treatment for their acute TMD symptoms and were recruited between 2008 and 2013. The participants were diagnosed using the Research Diagnostic Criteria for TMD (RDC/TMD) and assigned to a biobehavioral intervention, self-care intervention, or no intervention. Three outcomes were assessed: psychosocial distress, pain, and functioning; and treatment effectiveness was assessed according to TMD diagnosis. Outcome evaluations were conducted immediately postintervention as well as at 1 and 2 years postintervention. Analyses were conducted using two-level hierarchical multilevel linear models (MLMs).

RESULTS

Contrary to expectations, patients did not respond differently to the intervention based on their TMD diagnosis. Acute m-TMD patients, especially those with other comorbid TMD diagnoses, reported the highest levels of pain and pain-related symptoms and disability. They also exhibited poorer jaw functioning, especially if they were at high risk for chronic TMD.

CONCLUSION

This study indicates that acute m-TMD tends to result in more severe symptom presentations, particularly if diagnosed in combination with other TMD comorbidities. Additionally, patients do not appear to respond better to biobehavioral or self-care intervention on the basis of their TMD diagnosis.

Trends in management of myofacial pain

We systematically reviewed the myofascial pain publications in the literature. The aim of this article is to review the methods of management and their outcome and factors associated with prognosis. The topics of interest in the diagnostic process are myofascial trigger points electromyography, jaw tracking, joint sound recorder, sonography, and vibratography, exclusion of other orofacial pain and temporomandibular disorders. Management modalities are occlusal therapy, physiotherapy, multidimensional rehabilitation antinociceptive therapy, anti-inflammatory and analgesics, muscle relaxants, stretch, and spray technique, transcutaneous electric nerve stimulation, and in severe cases botulinum toxin may be tried. The disease required interdisciplinary interaction in terms of occlusal therapy, antinociceptive therapy and physiotherapy because management of the disease may be influenced by the specialist primarily treating the patients.

Methodological quality of a systematic review on physical therapy for temporomandibular disorders: influence of hand search and quality scales

The validity of a systematic review depends on completeness of identifying randomised clinical trials (RCTs) and the quality of the included RCTs. The aim of this study was to analyse the effects of hand search on the number of identified RCTs and of four quality lists on the outcome of quality assessment of RCTs evaluating the effect of physical therapy on temporomandibular disorders. In addition, we investigated the association between publication year and the methodological quality of these RCTs. Cochrane, Medline and Embase databases were searched electronically. The references of the included studies were checked for additional trials. Studies not electronically identified were labelled as “obtained by means of hand search”. The included RCTs (69) concerning physical therapy for temporomandibular disorders were assessed using four different quality lists: the Delphi list, the Jadad list, the Megens & Harris list and the Risk of Bias list. The association between the quality scores and the year of publication were calculated. After electronic database search, hand search resulted in an additional 17 RCTs (25%). The mean quality score of the RCTs, expressed as a percentage of the maximum score, was low to moderate and varied from 35.1% for the Delphi list to 54.3% for the Risk of Bias list. The agreement among the four quality assessment lists, calculated by the Interclass Correlation Coefficient, was 0.603 (95% CI, 0.389; 0.749). The Delphi list scored significantly lower than the other lists. The Risk of Bias list scored significantly higher than the Jadad list. A moderate association was found between year of publication and scores on the Delphi list (r = 0.50), the Jadad list (r = 0.33) and the Megens & Harris list (r = 0.43).

Complementary and alternative medicine for persistent facial pain

This article discusses complementary and alternative medicine (CAM), reviews literature on the prevalence of use of CAM by the general adult population in the United States and by patients with persistent facial pain, and summarizes published, peer-reviewed reports of clinical trials assessing the effects of CAM therapies for persistent facial pain. Results indicate that many patients use CAM for musculoskeletal pain, including persistent facial pain. Preliminary work on selected complementary therapies such as biofeedback, relaxation, and acupuncture seems promising; however, there are more unanswered than answered questions about cost-effectiveness, efficacy and mechanisms of action of CAM for persistent facial pain.

Efficacy of biofeedback-based treatments for temporomandibular disorders

Bibliographic searches identified 14 controlled and uncontrolled outcome evaluations of biofeedback-based treatments for temporomandibular disorders published since 1978. This literature includes two randomized controlled trials (RCTs) of each of three types of biofeedback treatment: (1) surface electromyographic (SEMG) training of the masticatory muscles, (2) SEMG training combined with adjunctive cognitive-behavioral therapy (CBT) techniques, and (3) biofeedback-assisted relaxation training (BART). A detailed review of these six RCTs, supplemented with information from non-RCT findings, was conducted to determine the extent to which each type of intervention met treatment efficacy criteria promulgated by the Association for Applied Psychophysiology and Biofeedback (AAPB). We conclude that SEMG training with adjunctive CBT is an efficacious treatment for temporomandibular disorders and that both SEMG training as the sole intervention and BART are probably efficacious treatments. We discuss guidelines for designing and reporting research in this area and suggest possible directions for future studies.

A review of complementary and alternative medicine use for treating chronic facial pain

BACKGROUND

The authors compiled information on the prevalence of complementary and alternative medicine, or CAM, use, as well as on reports of randomized clinical trials of CAM modalities used to treat chronic facial pain.

TYPES OF STUDIES REVIEWED

The authors searched several databases for reports of clinical trials randomizing patients who had facial pain to a CAM intervention or to a control or comparison group. Search terms included "complementary," "alternative," "acupuncture," "biofeedback," "relaxation," "herbal," "meditation," "massage," "yoga," "chiropractic," "homeopathic" and "naturopathic."

RESULTS

Three acupuncture trials, eight biofeedback trials and three relaxation trials met the authors' inclusion criteria. Across studies, results suggested that acupuncture, biofeedback and relaxation were comparable to conservative treatment (for example, an intraoral appliance) and warranted further study. The authors did not locate any randomized clinical trials that tested the effects of homeopathy, naturopathy, chiropractic, massage, meditation, yoga or herbal remedies for chronic facial pain.

CLINICAL IMPLICATIONS

Significant gaps in the scientific knowledge base limit the accuracy with which dental professionals can guide their patients regarding CAM approaches used to treat chronic facial pain.

Long-term efficacy of biobehavioral treatment of temporomandibular disorders

This study evaluated the relative long-term efficacy of biofeedback, cognitive-behavioral skills training (CBST), combined biofeedback and CBST (Combined), and no-treatment comparison groups in 108 patients suffering from chronic temporomandibular disorder (TMD). After an initial evaluation, patients were assigned to one of the four treatment conditions. The three biobehavioral treatment interventions consisted of 12 standardized sessions. Patients were reevaluated 1 year after completing treatment. Results demonstrated that patients who received the biobehavioral treatments reported significant improvement in subjective pain, pain-related disability, and mandibular functioning 1 year after receiving treatment. The no-treatment comparison group did not demonstrate such improvements. The combined biofeedback and CBST treatment produced the most comprehensive improvements across all outcome measures. These results again demonstrate the heuristic value of adopting a biopsychosocial perspective to the assessment and treatment of chronic medical/dental disorders such as TMD.

Awareness of physiological responding under stress and nonstress conditions in temporomandibular disorders

To test the hypothesis that individuals with temporomandibular disorders (TMD) have deficits in proprioceptive awareness, 20 TMD patients were compared with 20 nonpain individuals matched to the TMD patients on age and gender. Left and right frontalis, masseter, and temporalis were monitored, as were forearm extensor, heart rate, and skin conductance while the participants viewed a nonstressful film segment. Following the film segment, participants provided self-reports of these physiological responses. This sequence was repeated for a second, stressful film segment and for a third, non-stressful film segment. Correlations between physiological activity and self-report were used as measures of proprioceptive awareness. The results indicated that TMD subjects were most accurate in their awareness of facial muscle activity during the stress condition and least accurate in the two nonstress periods. Control subjects increased their accuracy of awareness at each time period, showing significantly greater accuracy than the TMD group in the last, nonstress period. TMD subjects more accurately perceived activity of the nonfacial muscle variables in the two nonstress periods than during the stress period. These findings may provide a mechanism for understanding clinical observations showing that TMD patients with myofascial pain engage in high levels of parafunctional oral activity without awareness.

Effects of intraoral appliance and biofeedback/stress management alone and in combination in treating pain and depression in patients with temporomandibular disorders

To assess the differential efficacy of two commonly used treatments for temporomandibular disorders (TMD), intraoral appliances (IAs) and biofeedback (BF), separately and in combination, two studies were conducted. The first study directly compared IA treatment, a combination of biofeedback and stress management (BF/SM), and a waiting list control group in a sample of 80 TMD patients. Both treatments were determined to be equally credible to patients, ruling out this potential threat to the validity of the results obtained. The results demonstrated that the IA treatment was more effective than the BF/SM treatment in reducing pain after treatment, but at a 6-month follow-up the IA group significantly relapsed, especially in depression, whereas the BF/SM maintained improvements on both pain and depression and continued to improve. The second study examined the combination of IA and BF/SM in a sample of 30 TMD patients. The results of this study demonstrated that the combined treatment approach was more effective than either of the single treatments alone, particularly in pain reduction, at the 6-month follow-up. These results support the importance of using both dental and psychologic treatments to successfully treat TMD patients if treatment gains are to be maintained.

Technological methods in the diagnosis and treatment of temporomandibular disorders

Although there have been numerous technological devices introduced for the diagnosis and treatment of temporomandibular disorders, many are either ineffective or are research tools without direct clinical application. This article reviews the various modalities and makes recommendations regarding their effectiveness based on the available clinical and scientific evidence.

Devices for the diagnosis and treatment of temporomandibular disorders. Part III: Thermography, ultrasound, electrical stimulation, and electromyographic biofeedback

This last article in the three-part series on devices for the diagnosis and treatment of temporomandibular disorders (TMD) compared the claimed diagnostic usefulness of thermography with the present scientific evidence. In a similar manner, the therapeutic efficacy of ultrasound, electrical stimulation, and electromyographic biofeedback was also reviewed. This evaluation concluded that the application of thermography to the diagnosis of TMD is limited by variations within and among subjects and by intrinsic problems with controls of the test environment. It also concluded that evidence that therapeutic ultrasound alone is useful for the treatment of TMD is lacking, that positive clinical results of electrical stimulation may not be due to specific therapeutic effects, and that it is doubtful that the use of electrical stimulation devices can produce a position of the mandible that has any diagnostic or therapeutic significance. There is evidence, however, that relaxation training, assisted by EMG biofeedback, can reduce daytime muscle activity.

Electromyographic studies of craniomandibular disorders: a review of the literature

Craniomandibular disorders have been investigated from many points of view, structurally and functionally. To evaluate the behaviour of the masticatory muscles, electromyography (EMG) has been widely used and the studies have emanated from many different paradigms. The purpose of this paper is to review articles in which EMG has been used to study symptomatic subjects. Findings from sleep studies and basic laboratory studies seem to support the hypothesis of a correlation between masticatory muscle hyperactivity and symptoms. Experimentally induced stress studies consistently show an increased activity in symptomatic subjects. Investigations of motor pauses, the often lengthened silent period, are summarized and discussed. Several different treatment strategies, particularly splints and biofeedback, have been evaluated using EMG, indicating a normalization, but controlled outcome studies are sparse. The use of EMG has thus substantially increased our knowledge of dysfunction of the masticatory system.