Coherence of jaw and neck muscle activity during sleep bruxism

Practice recommendations for the role of physiotherapy in the management of sleep disorders: the 2022 Brazilian Sleep Association Guidelines

This clinical guideline supported by the Brazilian Sleep Association comprises a brief history of the development of Brazilian sleep physiotherapy, outlines the role of the physiotherapist as part of a sleep health team, and describes the clinical guidelines in respect of the management of some sleep disorders by the physiotherapist (including sleep breathing disorders, i.e., obstructive sleep apnea, central sleep apnea, upper airway resistance syndrome, hypoventilation syndromes and overlap syndrome, and pediatric sleep breathing disorders; sleep bruxism; circadian rhythms disturbances; insomnia; and Willis-Ekbom disease/periodic limb movement disorder. This clinical practice guideline reflects the state of the art at the time of publication and will be reviewed and updated as new information becomes available.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2020 professional literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to this work to cover this broad topic. Specific subject areas addressed include prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders (TMDs); sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence day-to-day dental treatment decisions with a keen eye on future trends in the profession. With the tremendous volume of dentistry and related literature being published today, this review cannot possibly be comprehensive. The purpose is to update interested readers and provide important resource material for those interested in pursuing greater detail. It remains our intent to assist colleagues in navigating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the dental patients they encounter.

Effects of physical therapy for temporomandibular disorders on headache pain intensity: A systematic review

BACKGROUND

Physical therapy is regarded an effective treatment for temporomandibular disorders (TMD). Patients with TMD often report concomitant headache. There is, however, no overview of the effect of physical therapy for TMD on concomitant headache complaints.

OBJECTIVES

The aim of this study is to systematically evaluate the literature on the effectiveness of physical therapy on concomitant headache pain intensity in patients with TMD.

DATA SOURCES

PubMed, Cochrane and PEDro were searched.

STUDY ELIGIBILITY CRITERIA

Randomized or controlled clinical trials studying physical therapy interventions were included.

PARTICIPANTS

Patients with TMD and headache.

APPRAISAL

The Cochrane risk of bias tool was used to assess risk of bias.

SYNTHESIS METHODS

Individual and pooled between-group effect sizes were calculated according to the standardized mean difference (SMD) and the quality of the evidence was rated using the GRADE approach.

RESULTS

and manual therapy on both orofacial region and cervical spine. There is a very low level of certainty that TMD-treatment is effective on headache pain intensity, downgraded by high risk of bias, inconsistency and imprecision.

LIMITATIONS

The methodological quality of most included articles was poor, and the interventions included were very different.

CONCLUSIONS

Physical therapy interventions presented small effect on reducing headache pain intensity on subjects with TMD, with low level of certainty. More studies of higher methodological quality are needed so better conclusions could be taken.

Changes in jaw and neck muscle coactivation and coordination in patients with chronic painful TMD disk displacement with reduction during chewing

The treatment of a complex temporomandibular disorder (TMD), such as disk displacement with reduction (DDR) associated with arthralgia and myalgia, may depends on understanding the impairments in muscle function. The aim of this study was to investigate the behavior of the anterior temporalis, masseter and sternocleidomastoid muscles in the time and frequency domains during chewing in patients with chronic painful TMD-DDR using electromyographic (EMG) analysis. Thirty-three patients who met the diagnostic criteria for TMD and 32 volunteers without TMD (control group) underwent clinical examination, chewing pattern classification and EMG analysis. For the EMG analyses, the side of habitual unilateral chewing, as determined by the chewing pattern classification, was selected for recording; in cases of bilateral chewing, the recording side was randomly selected. The EMG-EMG coherence function and EMG-EMG transfer function (gain and phase) values were obtained at the first chewing frequency peak, and the working-side masseter signal was used as a reference in the analyses of the other muscles. Compared to the control group, the TMD group showed a longer chewing stroke duration (P = 0.01) as well as changes in the coactivation and coordination strategies of the jaw muscles, evidenced by greater relative energy expenditure (P< 0.01) and impaired differential recruitment (P< 0.05) and coherence (P< 0.01). Delays in peak and temporal asynchrony occurred in the jaw and neck muscles (P< 0.05). Patients with chronic painful TMD-DDR during chewing presented changes in the jaw and neck muscles, with more compromised function of the former, which are specific to chewing.

Coherence of jaw and neck muscle activity during sleep bruxism

BACKGROUND

Studies have shown co-contraction of jaw and neck muscles in healthy subjects during (sub) maximum voluntary jaw clenching, indicating functional inter-relation between these muscles during awake bruxism. So far, coherence of jaw and neck muscles has not been evaluated during either awake or sleep bruxism.

OBJECTIVE

The objective of this study was to evaluate the coherence between jaw and neck muscle activity during sleep bruxism.

METHODS

In a cross-sectional observational design, the electromyographic activity of jaw (masseter, temporalis) and neck (sternocleidomastoid, trapezius) muscles in individuals with "definite" sleep bruxism was measured using ambulatory polysomnography (PSG). Coherence for masseter-temporalis, masseter-sternocleidomastoid and masseter-trapezius was measured during phasic and mixed rhythmic masticatory muscle activity episodes using coherence-analysing software. Outcome measures were as follows: presence or absence of significant coherence per episode (in percentages), frequency of peak coherence (FPC) per episode and sleep stage.

RESULTS

A total of 632 episodes within 16 PSGs of eight individuals were analysed. Significant coherence was found between the jaw and neck muscles in 84.9% of the episodes. FPCs of masseter-temporalis were significantly positively correlated with those of masseter-sternocleidomastoid or masseter-trapezius (P < .001). Sleep stages did not significantly influence coherence of these muscular couples.

CONCLUSION

During sleep bruxism, jaw and neck muscle activation is significantly coherent. Coherence occurs independently of sleep stage. These results support the hypothesis of bruxism being a centrally regulated phenomenon.