Effect of mandibular mobilization on electromyographic signals in muscles of mastication and static balance in individuals with temporomandibular disorder: study protocol for a randomized controlled trial

Use of Surface Electromyography to Evaluate Effects of Therapeutic Methods on Masticatory Muscle Activity in Patients with Temporomandibular Disorders: A Narrative Review

The presented narrative review aims to present the impact of therapeutic methods on the masticatory muscle activity measured using surface electromyography (sEMG) in patients with temporomandibular disorders (TMDs). Original interventional studies with baseline data for diagnosed TMD groups with full-text articles in English published in scientific journals in the last ten years were included in the evaluation process. The following narrative review considered only clinical, controlled, and randomized studies. Articles that included the following parameters were qualified for this review: adult participants, diagnosis of temporomandibular disorder, the presence of a musculoskeletal dysfunction, no other severe comorbidities, use of therapeutic interventions, and sEMG measurement before and after the intervention. Ten papers were accepted and analyzed for the final evaluation in the presented review. Several studies using surface electromyographic examination prove the effectiveness of various therapies to normalize the bioelectrical activity of the masticatory muscles, either reduction during rest or increase during a functional task in patients diagnosed with temporomandibular disorders. This narrative review shows the influence of manual and physical treatments on electromyographic masticatory muscle activity, including soft tissue mobilization, transcutaneous electrical nerve stimulation, low-level laser therapy, and moist heat therapy. Changes in masticatory muscle activity coincided with changes in TMD-associated pain and range of mandibular mobility.

Simultaneous red and infrared light-emitting diodes reduced pain in individuals with temporomandibular disorder: a randomized, controlled, double-blind, clinical trial

The aim of the present study was to evaluate the effects of photobiomodulation (PBM) with the simultaneous use of red and infrared LEDs on pain and mandibular range of motion in individuals with temporomandibular disorder (TMD). Eighteen participants were randomly allocated to an LED group or control group. The device had 18 red LEDs (660 nm) and 18 infrared LEDs (850 nm), with a total power irradiated of 126 mW and 75.6 J per point. The device was placed in the regions of the temporomandibular joint (TMJ) and masticatory muscles once per day three times per week for 2 weeks. Pain intensity was measured using the visual analog scale (VAS). Mandibular range of motion was determined using digital calipers and considering different conditions (unassisted opening without pain, maximum opening with and without assistance, right and left lateral movements, and protrusion). Evaluations were performed before treatment, immediately after the first LED irradiation session and at the end of six sessions. A significant reduction in pain intensity was found in the LED group at the end of treatment compared to the control group (p < 0.001) as well as in the comparison between the pretreatment and end of treatment evaluations (p < 0.001). Regarding mandibular movements, no statistically significant differences between the LED group and control group were found at the end of treatment for any of the conditions analyzed or in the comparison between the beginning and end of treatment with LED. Photobiomodulation using a cluster with red and infrared LEDs induced a reduction in pain in individuals with temporomandibular disorder but did not alter mandibular range of motion in these individuals. Trial registration number: NCT03696706; retrospectively registered (ClinicalTrials.gov).

Effect of Manual Therapy and Splint Therapy in People with Temporomandibular Disorders: A Preliminary Study

Background: Isolated manual therapy techniques (MT) have shown beneficial effects in patients with temporomandibular disorders (TMD) but the effect of the combination of such techniques, together with the well-stablished splint therapy (ST) remains to be elucidated. Objective: This study was conducted to ascertain whether a combined program of MT techniques, including intraoral treatment, plus traditional ST improves pain and clinical dysfunction in subjects with TMD. Methods: A preliminary trial was conducted. 16 participants were assigned to either the MT plus ST-Experimental Group (EG, n = 8) or the ST alone—Control Group (CG, n = 8). Forty-five minute sessions of combined MT techniques were performed, once a week for four weeks. Three evaluations were conducted: baseline, post-treatment, and one-month follow-up. Outcome measures were pain perception, pain pressure threshold (PPT), TMD dysfunction, and perception of change after treatment. Results: EG showed significant reduction on pain, higher PPT, significant improvement of dysfunction and significantly positive perception of change after treatment (p < 0.05 all). Additionally, such positive effects were maintained at follow-up with a high treatment effect (R² explaining 26.6–33.2% of all variables). Conclusion: MT plus ST showed reduction on perceived pain (3 points decrease), higher PPT (of at least 1.0 kg/cm²), improvement of disability caused by pain (4.4 points decrease), and positive perception of change (EG: 50% felt “much improvement”), compared to ST alone.

Age-Related Changes in Postural Control in Physically Inactive Older Women

BACKGROUND AND PURPOSE

The maintenance of postural control is influenced by the complexity of a given task. Tasks that require greater attention and cognitive involvement increase the risk of falls among older adults. The aim of the present study was to evaluate the adaptation of the postural control system to different levels of task complexity in physically inactive young and older women.

METHODS

A cross-sectional study was conducted with adult women classified as physically inactive based on the results of the International Physical Activity Questionnaire. The participants were 27 young (20-30 years of age) and 27 older (60-80 years of age) women. Sway velocity of the center of pressure in the anterior-posterior and medial-lateral directions was calculated using a force plate under 6 conditions: standing directly on the force plate or on a foam placed over the force plate, eyes open or closed, and dual-task complexity with and without the foam.

RESULTS AND DISCUSSION

A 2-way analysis of variance revealed that sway velocity increased in both groups when the task conditions were altered. The older women exhibited significantly greater sway velocity compared with the young women on all tasks. However, the patterns of postural control adaptation to the different levels of complexity were similar among all participants.

CONCLUSIONS

In this study, the adaption of the postural control system to different levels of task complexity did not differ between physically inactive young and physically inactive older women. However, the physically inactive older women exhibited greater sway velocity compared with the young women.

Electromyography of the masticatory muscles during chewing in different head and neck postures - A pilot study

Objectives

The objectives of this pilot study were to analyze the electromyography (EMG) activity of masseter and anterior temporalis muscles during chewing in 2 different posture conditions: natural head posture (NHP) and maximum yet comfortable forward head posture (FHP) in healthy individuals; and to compare EMG activity between subjects based on their NHP during chewing.

Methods

Fifteen subjects participated. Sagittal head posture in sitting position was clinically assessed using a plumb line. Participants were classified as having FHP or upright head posture (UP). Surface EMG was used to evaluate superficial masseter and anterior temporalis bilaterally during chewing in NHP and FHP. Three trials with five chewing cycles were recorded. EMG data were normalized using a maximum voluntary contraction. An independent t-test was used to calculate differences between sides. If no differences were found, both sides were analyzed together. To analyze differences between the 2 conditions, a paired t-test was used. Independent t-test was used to calculate difference between subjects with UP and FHP.

Results

A significant increase in muscle activity was found for masseter muscle in the FHP condition. No differences were found in muscle activity in natural head position by posture classification. A trend of increased activity was observed for masseter and temporalis muscles during chewing in FHP.

Conclusion

Head and neck posture was found to influence masticatory muscle activity during the function of chewing. The results of this study may help clinicians to better understand the association between head and neck posture alterations with masticatory muscles related disorders.

Photobiomodulation with simultaneous use of red and infrared light emitting diodes in the treatment of temporomandibular disorder: study protocol for a randomized, controlled and double-blind clinical trial

INTRODUCTION

Temporomandibular disorder (TMD) is considered the main cause of orofacial pain of non-dental origin, and a public health problem. The symptomatology is muscular and/or articular pain, restriction of the mandibular range of motion, and changes in the mandibular movement pattern. Due to its complexity there are already treatments using various forms of therapy. Photobiomodulation using light sources, such as low-level laser or light emitting diodes (LED), with different wavelengths, in a single or combined form, allows one more therapeutic resource to be explored. The objective of this study is to evaluate the effects of photobiomodulation with the simultaneous use of red and infrared LEDs, on pain, range of mandibular movements, and on the electrical activity of masticatory muscles in individuals with TMD.

METHODS

A randomized, controlled, double-blind clinical trial is proposed, which will involve 33 individuals (n = 11 per group) of both sexes, ages 18 to 45 years in 3 groups: LED group; placebo group; and control group, submitted to 6 non-consecutive sessions of photobiomodulation totaling 2 weeks of treatment. The Research Diagnostic Criteria for Temporomandibular Disorders-RDC/TMD will be used to assess and determine the participants' TMD. The pain will be assessed using the Visual Analog Scale - VAS, the mandibular range of motion will be determined with the aid of a digital caliper, and the electrical activity of the masticatory muscles will be verified by electromyography. A mixed plate of 18 red LEDs-660 nm and 18 infrared LEDs-850 nm with power of 3.5 mW per LED, 4.45 mW/cm, radiant exposure of 5.35 J/cm, will be used for photobiomodulation. The irradiated area will be 14.13 cm, and energy of 75.6 J, in the TMJ region and in the bilateral masseter and temporal muscles. Participants from all groups will be reassessed after the first therapeutic intervention, and at the end of treatment.

DISCUSSION

We expect the use of photobiomodulation with LEDs, infra and red, to reduce pain, improve temporomandibular joint function in patients with TMD, and thus improve the general conditions of the patient.

Association of facial massage, dry needling, and laser therapy in Temporomandibular Disorder: case report

This case report aims to evaluate the treatment of Temporomandibular Disorder (TMD) of muscular origin by associating facial massage (FM), dry needling (DN), and low-level laser therapy (LLLT). The pre- and post-treatment evaluations consisted of clinical examinations based on the Research Diagnostic Criteria (RDC) for TMD, pain intensity quantification by means of the Visual Analog Scale (VAS), mandibular movement measurement, and electromyographic (EMG) analysis of the masseter and temporal muscles. Post-therapy assessment indicated a decrease in pain sites of 58%, in pain intensity mean (1.3), and an increase in the maximum aperture of 10 mm, in addition to normalization of EMG signals. We conclude that, after application of the treatment protocol, there was a decrease in painful sites, gain in amplitude of mandibular movements, and normalization of EMG activity.

Reduced corticostriatal functional connectivity in temporomandibular disorders

Although temporomandibular disorders (TMD) have been associated with abnormal gray matter volumes in cortical areas and in the striatum, the corticostriatal functional connectivity (FC) of patients with TMD has not been studied. Here, we studied 30 patients with TMD and 20 healthy controls that underwent clinical evaluations, including Helkimo indices, pain assessments, and resting-state functional magnetic resonance imaging scans. The FCs of the striatal regions with the other brain areas were examined with a seed-based approach. As seeds, we used the dorsal caudate, ventral caudate/nucleus accumbens, dorsal caudal putamen, and ventral rostral putamen regions. Voxel-wise comparisons with controls revealed that the patients with TMD exhibited reduced FCs in the ventral corticostriatal circuitry, between the ventral striatum and ventral frontal cortices, including the anterior cingulate cortex and anterior insula; in the dorsal corticostriatal circuitry, between the dorsal striatum and the dorsal cortices, including the precentral gyrus and supramarginal gyrus; and also within the striatum. Additionally, we explored correlations between the reduced corticostriatal FCs and clinical measurements. These results directly supported the hypothesis that TMD is associated with reduced FCs in brain corticostriatal networks and that these reduced FCs may underlie the deficits in motor control, pain processing, and cognition in TMD. Our findings may contribute to the understanding of the etiologies and pathologies of TMD.

Immediate effect of transcranial direct current stimulation combined with functional electrical stimulation on activity of the tibialis anterior muscle and balance of individuals with hemiparesis stemming from a stroke

[Purpose] The aim of the present study was to evaluate the immediate effects of transcranial direct current stimulation (tDCS) and functional electrical stimulation (FES) on activity of the tibialis anterior muscle (TA) and static balance of individuals with hemiparesis stemming from stroke. [Subjects and Methods] A randomized, double-blind, crossover, clinical trial conducted with 30 individuals with chronic post-stroke hemiparesis. Median frequency of electrical activity of the TA were determined using electromyography in five contractions concentrics and Static balance (body sway velocity and frequency), both before and immediately after the intervention. The participants were submitted to four 20-minute intervention protocols with 48-hour interval: anodal tDCS + sham FES; sham tDCS + active FES; anodal tDCS + active FES and sham tDCS + sham FES. Anodal tDCS was administered over C3 or C4, the cathode was positioned in the supraorbital region on the contralateral side and FES was administered to the affected TA. [Results] No significant differences among the protocols were found regarding electrical activity of the TA and static balance. [Conclusion] The results demonstrate that tDCS alone or in combination with FES had no immediate effect on electrical activity of the TA and static balance of the 30 individuals analyzed.

Effects of Massage Therapy and Occlusal Splint Usage on Quality of Life and Pain in Individuals with Sleep Bruxism: A Randomized Controlled Trial

PURPOSE

The aim of the present study was to investigate the effects of massage therapy on the masticatory muscles and occlusal splint usage on quality of life and pain in individuals with sleep bruxism.

METHOD

A randomized, controlled, blinded, clinical trial was conducted involving 78 volunteers aged 18 to 40 years with sleep bruxism. Quality of life and pain assessments were performed.

RESULTS

Significant differences (p < 0.05) were found on the physical functioning, general health state, vitality, role emotional and mental health subscales. A large effect size was found for all treatment protocols with regard to pain. The largest effect was found in the combined treatment group.

CONCLUSIONS

The findings of the present study reveal that the occlusal splint usage alone led to improvements in components of quality of life among individuals with sleep bruxism. Moreover, both treatments (occlusal splint usage and massage therapy on the masticatory muscles) led to a reduction in pain.

Temporomandibular Joint Hypermobility Manifestation Based on Clinical Observations

BACKGROUND

Joint range of motion might affected by some factors like laxity and increase joint mobility. Generalized joint hypermobility and temporomandibular joint hypermobility (TMJH) are reported as risk factors for temporomandibular disorders. The aim of this study was to survey the etiological factors of TMJH and its relations to habitual status.

MATERIALS AND METHODS

In this cross-sectional descriptive study, 69 patients with TMJH were involved. After profiling personal information and medical history, the patients were divided into three groups based on their maximum mouth opening (MMO) as follow: (Light) MMO of 50-55 mm, (moderate): MMO between 55 and 65 mm, (severe) MMO >65 mm. For subjective observations, patients were asked to fill the prepared questionnaire. The objective evaluations conducted by a specialist. Finally, all the data subjected Chi-Square test by using SPSS software version 22 at a significant level of 0.05.

RESULTS

TMJH was more common in women (74.2%). The light group had significant differences with other groups in the discomfort of TMJ and TMJ sound (P < 0.05). Furthermore, sever group manifested highest percentage of masticatory pains, significantly (P < 0.05).

CONCLUSION

It can be concluded that pain in TMJ would have a correlation with MMO.

Condylar distances in hypermobile temporomandibular joints of patients with excessive mouth openings by using computed tomography

Objectives: hypermobility in Temporomandibular joint (TMJ) can manifest higher range of motions in mandible. The aim of this study was to compare the position and distances of the head of condyle to glenoid fossa in TMJs of healthy individuals and patients with mild, moderate and severe TMJ hypermobility. Material and Methods: In this clinical study, 69 patients (between the ages of 22 to 42) with manifestation of joint hypermobility were included and Computed tomography were administered for both TMJs. The patients were divided into three groups based on their maximum mouth opening (MMO): (A) with MMO of 50-55 mm; (B) with MMO between 55 to 65 mm; and (C) with MMO >65 mm. Also, 15 healthy people with profiled tomography in the last 6 months were assumed as control group (N) with normal MMO (<50 mm). The position of condyle from articular eminence while MMO; and the distances from anterior, superior and posterior border of condyle and facing wall of glenoid fossa were measured in closed mouth from the tomography of all contributors. The collected data were analyzed by one-way ANOVA, Post Hoc and Chi-Square tests using SPSS software version 15 at significant level of 0.05. Results: The superior and posterior distances were significantly higher in groups A, B and C than healthy individuals (all P values<0.01). The anterior distance was significant between groups B and N only in right TMJ (P=0.013). Conclusions: TMJ hypermobility showed the characteristic of increased condylar distance in posterior and superior specially in higher excessive mouth opening.

Key words:Computed tomography, joint hypermobility, mandibular condyle, mouth opening.

Effects of massage therapy and occlusal splint therapy on electromyographic activity and the intensity of signs and symptoms in individuals with temporomandibular disorder and sleep bruxism: a randomized clinical trial

Introduction

Temporomandibular disorder (TDM) is the most common source of orofacial pain of a non-dental origin. Sleep bruxism is characterized by clenching and/or grinding the teeth during sleep and is involved in the perpetuation of TMD. The aim of the present study was to investigate the effects of massage therapy, conventional occlusal splint therapy and silicone occlusal splint therapy on electromyographic activity in the masseter and anterior temporal muscles and the intensity of signs and symptoms in individuals with severe TMD and sleep bruxism.

Methods

Sixty individuals with severe TMD and sleep bruxism were randomly distributed into four treatment groups: 1) massage group, 2) conventional occlusal splint group, 3) massage + conventional occlusal splint group and 4) silicone occlusal splint group. Block randomization was employed and sealed opaque envelopes were used to conceal the allocation. Groups 2, 3 and 4 wore an occlusal splint for four weeks. Groups 1 and 3 received three weekly massage sessions for four weeks. All groups were evaluated before and after treatment through electromyographic analysis of the masseter and anterior temporal muscles and the Fonseca Patient History Index. The Wilcoxon test was used to compare the effects of the different treatments and repeated-measures ANOVA was used to determine the intensity of TMD.

Results

The inter-group analysis of variance revealed no statistically significant differences in median frequency among the groups prior to treatment. In the intra-group analysis, no statistically significant differences were found between pre-treatment and post-treatment evaluations in any of the groups. Group 3 demonstrated a greater improvement in the intensity of TMD in comparison to the other groups.

Conclusion

Massage therapy and the use of an occlusal splint had no significant influence on electromyographic activity of the masseter or anterior temporal muscles. However, the combination of therapies led to a reduction in the intensity of signs and symptoms among individuals with severe TMD and sleep bruxism.

Trial registration

This study is registered in August, 2014 in the ClinicalTrials.gov (NCT01874041).

Electronic supplementary material

The online version of this article (doi:10.1186/s12998-014-0043-6) contains supplementary material, which is available to authorized users.