Behavior analysis of electromyographic activity of the masseter muscle in sleep bruxers

Comparison of the efficacy of occlusal splint and botulinum toxin therapies in patients with temporomandibular disorders with sleep bruxism

PURPOSE

This study aims to evaluate the efficacy of occlusal splint and botulinum toxin (BTX) therapies for improving the pain scores and mouth opening in patients with temporomandibular disorders (TMD) with sleep bruxism (SB).

MATERIALS AND METHODS

A retrospective cohort study was conducted based on clinical record reviews of patients with TMD symptoms (e.g., temporomandibular joint [TMJ] pain, masticatory muscle pain, TMJ internal derangements, joint sounds, and limited mouth opening) and SB. The patients were divided into two groups: occlusal splint group and BTX group. Maximum unassisted mouth opening (MMO) and pain score on a visual analogue scale (VAS) before treatment and at 1‑, 3‑, and 6‑month follow-up were analyzed to evaluate the clinical outcomes.

RESULTS

A total of 60 patients (49 women and 11 men, mean age 34.63 ± 11.85 years) were enrolled. Each group had 30 patients. The comparisons of the groups at 1 and 3 months after treatment indicated that the BTX group had higher MMO values (P = 0.013 and 0.034, respectively) and lower VAS scores than the occlusal splint group (P = 0.000 and 0.001, respectively). No difference between the two groups was observed 6 months after treatment (P > 0.05).

CONCLUSIONS

Both occlusal splint and BTX treatment methods were successful in treating TMD with SB. BTX provided patients with rapid relief in the early period; therefore, BTX can be recommended as a primary treatment option in patients with greater pain.

HEART RATE AND LOWER LIMB MUSCLE ACTIVITY ON CYCLE ERGOMETER

ABSTRACT Introduction: Muscle activity in the pedal stroke movement on a cycle ergometer can be measured by surface electromyography, as an effective and improved method for studying muscle action and objectively determining the different action potentials of the muscles involved in specific movements. Heart rate behavior is an important factor during exercise with load. Objective: To identify heart rate behavior and pattern of muscle activity of the rectus femoris and vastus medialis in healthy subjects in the pedaling dynamic at different loads, submaximal test, on an instrumented cycle ergometer. Methods: 20 healthy adults were evaluated. Heart rate measurement was performed, together with electromyographic analysis, in the time domain, of the rectus femoris and vastus medialis muscles during incremental exercise of the lower limbs on the cycle ergometer. Results: Heart rate behavior presented significant difference for p≥0.05 in relation to increased loads. The EMG signal intensity from the vastus medialis muscle (normalized RMS value) in each quadrant of the pedaling cycle showed significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants III and IV. In the rectus femoris (RF) muscle, there was significant difference for p≥0.05 in relation to quadrants I, II and IV and significant difference for p≥0.05 in relation to quadrants I, II and III. Conclusion: An increase in heart rate proportional to the increase in load was observed, as well as an increase in the amplitude of the electromyographic signal proportional to the increase in load. It was possible to identify the pattern of muscle activation in the studied quadrants during pedal stroke movements, independent of load. Level of evidence III; Study of non-consecutive patients; without uniform application of the “gold” standard reference.

Treatment of chronic pain associated with bruxism through Myofunctional therapy

Temporomandibular disorders such as bruxism may cause painful clinical conditions and over time lead to chronic facial pain. A combination of therapeutic strategies that are usually undertaken by dentists and gnathologists to reduce bruxism episodes and consequently pain, are myofunctional therapy, pharmacological treatment, intraoral interventions and behavioural treatments. The aim of this work was to understand if myofuntional therapy alone can be a useful therapy for the reduction of chronic facial pain. 24 patients, 9 male and 15 female, age ranging between 25 and 45, were treated with a myofunctional therapy for 9 month. Each patient was evaluated through a numeric pain intensity scale ranging from 0 to 10 and the number of bruxism episodes/hour per patient were also recorded; electromyographic examinations of the temporal, masseter, sternocleidomastoid and digastric muscles were performed to evaluate muscle activation. Each patient was tested before (T0) and after (T1) the treatment period. Pain intensity decreased from T0 to T1 (8.13±0.39 vs. 1.75±2.43, respectively, p<0.01). The number of bruxism episodes also significatively decreased between T0 and T1 (24 vs. 9, p<0.01). Electromyographic assessment showed a decrease in the tonic activity of the masseter muscle (T0: 1.88±0.31 vs. T1: 1.4±0.25 μV; p<0.05) and a reduction of the electric activity of the temporal and digastric muscles during serration of the mandible (T0: 167.9±19.6 μV Vs T1: 144.6+16.43 μV; p<0.05 and T0: 58.97+8.38 μV Vs T1: 52.79+7.44 μV; p<0.05, respectively). Myofunctional therapy could be used to reduce facial pain as a consequence of bruxism episodes.

Knowledge of parents/guardians about nocturnal bruxism in children and adolescents

BACKGROUND

Bruxism is a repetitive jaw-muscle activity characterized by the clenching or grinding of teeth and/or the bracing or thrusting of the mandible.

OBJECTIVE

This study assessed parents/guardians' knowledge of nocturnal bruxism in children/adolescents.

METHOD

A cross-sectional study using a validated questionnaire was carried out on 134 Brazilian guardians. Data were analyzed descriptively and through the chi-square test to assess the association if guardians reported bruxism and the causes and consequences of nocturnal bruxism.

RESULTS

Mothers (68.7%) were the main contributors; 23.1% said their child had bruxism. Although most participants (73.9%) had no opinion, some believe bruxism is linked to emotional stress (13.4%), mysticism/religiosity (3.7%), health (3.7%) or dental problems (3.0%), and presence of parasites (2.2%). Among the parents/guardians of children without bruxism, 81.9% were unaware of some possible cause versus 18.1% of those with bruxism (p=0.011). There was no association between children with bruxism and the type of sleep (p=0.191) or sleep duration (p=0.377). The majority (90.3%) of guardians whose children have bruxism believe the condition affects their health (p=0.006).

CONCLUSION

Guardians have a widespread ignorance about the causes and consequences of sleep bruxism.

Evaluation of electromyographic signals in children with bruxism before and after therapy with Melissa Officinalis L-a randomized controlled clinical trial

[Purpose] Bruxism is a repetitive muscle activity involving the clenching or grinding of one’s teeth during sleep or waking hours. Melissa officinalis L. may be employed as a natural therapy due to the sedative, anxiolytic, anti-inflammatory, and anti-spasm properties of the chemical constituents of the essential oil obtained from its leaves. The aim of the present study was to evaluate electromyographic signals in the temporal muscle using the BiteStrip^® test on children with sleep bruxism before and after therapy with Melissa officinalis L. [Subjects and Methods] The subjects were randomly allocated to two groups. Group 1 (n = 12) ingested a tincture containing Melissa officinalis L. for 30 days. Group 2 (n = 12) received a placebo solution with the same dose and frequency as Group 1. The Wilcoxon and Mann-Whitney tests were employed for statistical analysis. [Results] The sample was made up of 24 children aged 6 to 10 years. No statistically significant differences were found between initial and final muscle activity in either group or in an intergroup comparison. [Conclusion] Use of the Melissa officinalis L. tincture at the dose employed did not lead to a reduction in muscle activity in children with bruxism.

Psychosocial aspects of bruxism: the most paramount factor influencing teeth grinding

In clinical practice, patients suffering from an occlusal parafunctional activity have increased. It can be observed that a negative influence of environment aggravates patient's health. The aim of this paper is to present the impact of environment and development of human civilization on the prevalence of bruxism and the correlation between them. The authors grasp the most relevant aspects of psychological and anthropological factors changing over time as well as their interactions and describe a relationship between chronic stress and bruxism. Current literature shows how contemporary lifestyle, working environment, diet, and habits influence the patient's psychoemotional situation and the way these factors affect the occluso-muscle condition.

Influence of temporomandibular disorder on temporal and masseter muscles and occlusal contacts in adolescents: an electromyographic study

Background

The aim of the present study was to analyse the influence of temporomandibular disorder (TMD) on electromyographic activity in the masseter and temporal muscles of adolescents and investigate a possible association with the number of occlusal contacts.

Methods

The Helkimo Index was administered for the diagnosis of TMD and classification of the adolescents into three groups: without TMD; with mild TMD; and with moderate/severe TMD. Carbon paper was used for the determination of occlusal contact points. A standardised electromyographic evaluation was performed on the masticatory muscles at rest, during habitual chewing and during maximum voluntary clenching. The readings were normalised to maximum voluntary clenching. Statistical analysis involved the chi-squared test and Fisher’s exact test. The Kruskal-Wallis test and one-way analysis of variance with Dunn’s post hoc test were used to compare differences between groups. Pearson’s correlation coefficients (r) were calculated for the determination of correlations between the number of occlusal contacts and RMS values.

Results

Electromyography revealed significant differences in the right and left masseter and temporal muscles at rest and during chewing among the three groups. These differences were not observed during maximum voluntary clenching. No statistically significant differences were found between the groups with and without TMD regarding the number of occlusal contacts.

Conclusion

Electromyographic activity in the masseter and temporal muscles was greater among adolescents with moderate to severe TMD.

Effectiveness of two physical therapy interventions, relative to dental treatment in individuals with bruxism: study protocol of a randomized clinical trial

Background

Bruxism is a parafunctional habit characterized by grinding and/or clenching of the teeth. It may happen while awake (awake bruxism) or while sleeping (sleep bruxism). In adults, the prevalence is 20% for the awake bruxism and 8% for the sleep bruxism. Peripheral, central, and psychosocial factors influence the disorder, which may predispose to pain in the masticatory muscles and neck, headache, decreased pain thresholds in the masticatory and cervical muscles, limitation mandibular range of motion, sleep disorders, stress, anxiety, depression, and overall impairment of oral health. The aim of this study is to compare two distinct physical therapy interventions with dental treatment in pain, mandibular range of motion, sleep quality, anxiety, stress, depression, and oral health in individuals with bruxism.

Methods/Design

Participants will be randomized into one of three groups: Group 1 (n = 24) intervention will consist of massage and stretching exercises; Group 2 (n = 24) will consist of relaxation and imagination therapies; and Group 3 (n = 24) will receive dental treatment. The evaluations will be performed at baseline, immediately after treatment, and at 2-month follow-up. Pain intensity will be assessed using the visual analogical scale, while pain thresholds will be determined using dolorimetry. Mandibular range of motion will be assessed using digital pachymeter. Sleep quality will be assessed by the Pittsburgh Sleep Quality Index, anxiety by the State-Trait Anxiety Inventory, stress by the Perceived Stress Scale-10, depression by the Beck Depression Inventory, and oral health will be assessed using the Oral Health Impact Profile - 14. Significance level will be determined at the 5% level.

Discussion

This project describes the randomization method that will be used to compare two physical therapy interventions with dental treatment in the management of pain, mandibular range of motion, sleep quality, anxiety, stress, depression, and oral health in individuals with bruxism. The study will support the practice of evidence-based physical therapy for individuals with bruxism. Data will be published after study is completed.

Trial registration

ClinicalTrials.gov, NCT01778881

A novel protocol for occlusal splint adjustment to treat TMD in sleep bruxism

INTRODUCTION: Sleep bruxism (SB) is a stereotypical movement disorder that is characterized by rhythmic masticatory muscle activity associated with tooth grinding and occasional jaw clenching. OBJECTIVES: The aim of this study was to determine the relief time for temporomandibular disorders (TMD), cervical and otological signs and symptoms in patients with BS treated with occlusal splints (OS) for a period of 180 days. MATERIALS AND METHODS: Thirty patients, between ages 22 and 53 years old, presenting SB and TMD, including cervical and otological symptoms, were enrolled in this study. The patient’s treatment protocol consisted of using the OS applying a novel adjustment protocol. The total follow-up period was 180 days. The paired Student t-test was used to compare before and after long-term OS treatment. RESULTS: For all variables, the results were statistically significant (p < 0.001). As to the TMD symptoms, in most patients the relief of pain in masseter, temporalis, cervical and TMDs occurred in the 3rd month. Twenty percent of the patients were aware of clenching teeth while awake and reported that this parafunction decreased by the end of 6 months, and 90% reported an improvement in sleep quality as well. CONCLUSION: The use of an OS with a novel adjustment protocol was an effective treatment for TMD sign and symptoms in patients with SB.

Statistical Methods and Artificial Neural Networks Techniques in Electromyography

This work represents a comparative study for the activity of the masseter muscle for patients before trial base denture insertion and the activity of the same muscle after trial denture base insertion for both right and left masseter muscles. The study tried to find if there were significant differences in the activity of the masseter muscle before and after patients wearing their trial denture base using two approaches: parametric statistical methods and a Neural Network Classifier. Statistical analysis was performed on three feature vectors extracted from autoregressive (AR) modeling, Discrete Wavelet Transform (WT), and from Wavelet Packet Transform (WP). The least significant difference test and the student t-test have not proved significant differences in the masseter muscle activity before and after wearing denture. However, using the same feature vectors, a neural network classifier has proved that there are significant differences in the masseter muscle activity before and after patients wearing trial denture base.

Trapezius upper portion trigger points treatment purpose in positional release therapy with electromyographic analysis

BACKGROUND

This quantification process is made through electromyography analysis. This technique of analysis is able to provide a general view of the tension decrease in the superior muscle fibers of the trapezius after therapy.

AIMS

The focus of the present work is to evaluate the treatment of the cervicobrachialgia by Positional Release Therapy (PRT).

MATERIAL AND METHODS

The present work studies six patients, with ages 44 to 63 (1 male and 5 female) who present tension in the trapezius upper portion fibers. All patients were submitted to 10 session of 30 minutes each. The electromyography was collected on the first and tenth day of treatment.

RESULTS

The results demonstrated a progressive decrease of pain in each session. The tension was evaluated by the electromyography analysis, which showed the relations between time of treatment and less pain.

CONCLUSION

With these results, it was possible to verify quantitatively the efficiency of the PRT in the improvement of life quality.

Electromyographic analysis of masseter and anterior temporalis muscle in sleep bruxers after occlusal splint wearing

Bruxism is widely defined as an anxiety response to environmental stress. Occlusal splints are frequently used in sleep bruxism, to protect teeth from damage resulting from the contraction force of mandibular muscles, or to reduce the orofacial pain by relaxing masticatory muscles. Surface electromyography (EMG) of the right and left masseter and temporalis muscles was performed in 15 women presenting sleep bruxism and temporomandibular disorders related to occupational stress, after nocturnal use of the occlusal splint. The EMG signals were recorded twice per patient: After a work shift (pre-splint) and after a night of sleep with the occlusal splint (post-splint) before a new workday. The parametric t-paired test was used to compare differences of the RMS amplitude between pre and post-splint records, for resting and maximal clenching effort. The level of significance for each comparison was set to p < 0.05. The results of the study supports the premise that the use of occlusal splint reduces EMG activity in the masseter and anterior temporalis muscles, in patients who presented with sleep bruxism related to occupational stress.