Influence of Experimental Esophageal Acidification on Sleep Bruxism

Summary Background Most rhythmic masticatory muscle activities (RMMAs) have been shown to be accompanied with limb movements (LMs) in sleep bruxism (SB) patients during sleep. Objectives To compare the relationships between RMMAs and LMs in SB patients and normal subjects. Methods Polysomnographic recordings were performed on eight SB patients and nine normal subjects and the frequencies and durations of RMMAs as well as LMs were determined. Linear regression and correlation analysis were performed to study the relationship between durations of RMMAs and LMs when RMMAs occurred with LMs. Results Most LMs in SB patients, but not in normal subjects, were accompanied with RMMAs. RMMAs in SB patients were more likely to be isolated, phasic or mixed, while RMMAs in normal subjects were more likely to be tonic. The frequencies of LMs, isolated RMMAs and RMMAs accompanied with LMs in SB patients were significantly higher than those in normal subjects. Furthermore, linear regression and correlation analysis showed that duration of RMMAs was significantly associated with that of LMs when RMMAs occurred with LMs. The duration of RMMAs, when accompanied with LMs, in SB patients was significantly longer than that in normal subjects. Conclusions Close relationships between LMs and RMMAs exist in SB patients and normal subjects, and SB episodes may be part of cortical arousal responses and the increased cortical activities associated with SB episodes may not just be localised to the central nervous system (CNS) that controls jaw movements but may also include other parts of CNS that controls LMs.

Section: Discussionsupporting

confidence: 53%

Section: Introductionmentioning

confidence: 99%

Characterisation of the relationships between rhythmic masticatory muscle activities and limb movements in patients with sleep bruxism

Han

Wang

Zhong

et al. 2019

“…Notably, although supporting evidence is still inconclusive, in some individuals the behaviour may even have positive consequences for the bruxer (eg, being the ending episode of respiratory arousals, so as to prevent the collapse or restore the patency of the upper airway whilst asleep 16,17 ; or reducing the risk of detrimental chemical tooth wear by increasing salivation in case of gastro-oesophageal reflux 18 ), which would classify bruxism as a potential protective factor that is an attribute that decreases the chance of a negative health outcome. In addition, it can be associated with other clinical conditions (eg, sleep apnoea or other sleep disorders) or symptoms (eg, xerostomia) without a causeandeffect relationship.…”

Section: Bruxism Statusmentioning

confidence: 99%

International consensus on the assessment of bruxism: Report of a work in progress

Lobbezoo

Ahlberg

Raphael

et al. 2018

745

1,249

SummaryIn 2013, consensus was obtained on a definition of bruxism as repetitive masticatory muscle activity characterised by clenching or grinding of the teeth and/or by bracing or thrusting of the mandible and specified as either sleep bruxism or awake bruxism. In addition, a grading system was proposed to determine the likelihood that a certain assessment of bruxism actually yields a valid outcome. This study discusses the need for an updated consensus and has the following aims: (i) to further clarify the 2013 definition and to develop separate definitions for sleep and awake bruxism; (ii) to determine whether bruxism is a disorder rather than a behaviour that can be a risk factor for certain clinical conditions; (iii) to re-examine the 2013 grading system; and (iv) to develop a research agenda. It was concluded that: (i) sleep and awake bruxism are masticatory muscle activities that occur during sleep (characterised as rhythmic or non-rhythmic) and wakefulness (characterised by repetitive or sustained tooth contact and/or by bracing or thrusting of the mandible), respectively; (ii) in otherwise healthy individuals, bruxism should not be considered as a disorder, but rather as a behaviour that can be a risk (and/or protective) factor for certain clinical consequences; (iii) both non-instrumental approaches (notably self-report) and instrumental approaches (notably electromyography) can be employed to assess bruxism; and (iv) standard cut-off points for establishing the presence or absence of bruxism should not be used in otherwise healthy individuals; rather, bruxismrelated masticatory muscle activities should be assessed in the behaviour’s continuum.

“…Although a considerable number of factors investigated in included SR presented increased odds/risk for the presence of bruxism, it is proposed that bruxism could potentially act as a protective factor by reducing the likelihood of negative events for certain conditions . For example, by increasing salivation rate, SB might reduce the risk of detrimental chemical tooth wear in case of gastro‐oesophageal reflux . Therefore, although gastro‐oesophageal reflux might induce SB, this might act as a protective factor .…”

Section: Discussionmentioning

confidence: 99%

Bruxism: An umbrella review of systematic reviews

Melo

Duarte

Pauletto

et al. 2019

124

135

Objectives To synthesise available knowledge about both sleep (SB) and awake bruxism (AB) as depicted by previous published systematic reviews (SR). Methods SR investigating any bruxism‐related outcome were selected in a two‐phase process. Searches were performed on seven main electronic databases and a partial grey literature search on three databases. Risk of bias of included SR was assessed using the “University of Bristol's tool for assessing risk of bias in SR”. Results From 1038 studies, 41 SR were included. Findings from these SR suggested that (a) among adults, prevalence of AB was 22%‐30%, SB (1%‐15%), and SB among children and adolescents (3%‐49%); (b) factors consistently associated with bruxism were use of alcohol, caffeine, tobacco, some psychotropic medications, oesophageal acidification and second‐hand smoke; temporomandibular disorder signs and symptoms presented a plausible association; (c) portable diagnostic devices showed overall higher values of specificity (0.83‐1.00) and sensitivity (0.40‐1.00); (d) bruxism might result in biomechanical complications regarding dental implants; however, evidence was inconclusive regarding other dental restorations and periodontal impact; (e) occlusal appliances were considered effective for bruxism management, although current evidence was considered weak regarding other therapies. Conclusions Current knowledge from SR was mostly related to SB. Higher prevalence rates were found in children and adolescents than in adults. Associated factors and bruxism effects on stomatognathic structures were considerably heterogeneous and inconsistent. Overall good accuracy regarding portable diagnostic devices was found. Interventions' effectiveness was mostly inconclusive regarding the majority of available therapies, with the exception of occlusal appliances.