This study provided an overview of the knowledge on the main sleep-related disorders and conditions affecting the prognosis of dental treatment: sleep bruxism (SB), obstructive sleep apnea (OSA), and gastroesophageal reflux disease (GERD). Current scientific evidence seems to suggest that these phenomena (ie, SB, OSA, GERD) belong to a circle of mutually relating sleep disorders and conditions where dental practitioners can play a key role in diagnosis and treatment.

OBJECTIVE: Sleep bruxism (SB) and obstructive sleep apnoea (OSA) seem to be mutually associated. This study investigates the relationship between current SB and OSA-related symptoms and the difference in OSA-related symptoms between groups based on a history of SB.
METHODS: An online survey was drafted to report the presence of SB and OSA in sample of 243 individuals (M = 129;F = 114;mean(SD)age = 42.4 ± 14.4 years). The Subject-Based Assessment strategy recommended in the \'Standardized Tool for the Assessment of Bruxism\' (STAB) was adopted to assess SB. To evaluate OSA-related symptoms, Epworth Sleepiness Scale (ESS) and STOP-BANG questionnaires were adopted. Correlations between current SB and OSA-related symptoms were evaluated by Spearman test. ESS and STOP-BANG scores were compared by Mann-Whitney U test in individuals with and a without positive SB history.
RESULTS: Current SB and SB history were reported by 45.7% and 39.1% of the sample, respectively. 73.7%, 21% and 5.3% of the responders showed a low, intermediate and high risk of OSA, respectively. Neither significant correlations between current SB and OSA nor significant differences between SB groups emerged.
CONCLUSIONS: This study did neither find any significant correlation between self-report of current SB and OSA nor significant differences in ESS and STOP-BANG scores between groups based on SB history.

BACKGROUND: Bruxism is a behaviour that has several consequences in an individual\'s life, especially when it starts in childhood. However, bruxism can be a potential protective factor, which is an attribute that reduces the chance of a negative health outcome.
OBJECTIVE: To evaluate the incidence of sleep bruxism (SB) and dental wear in children and adolescents.
METHODS: This longitudinal study began in 2014 and 2016 (baseline) with initial 1816 children followed for 5 and 3 years, respectively. The follow-up data collection started in 2019. The diagnosis of SB was parents report (baseline) and self-report (follow-up) due to age groups of each phase, and questions related to symptoms of SB were collected. Five calibrated examiners (kappa >0.7) collected the clinical data. The clinical variables were dental erosion and dental wear. Contextual, individual, behaviour and clinical characteristics were collected. A multilevel logistic regression model was used to investigate the association of contextual, individual, behaviour and clinical characteristics with SB. Poisson regression for repeated measures was performed to evaluate the incidence of SB and dental wear (incidence rate ratio-IRR and confidence interval-95% CI).
RESULTS: Two hundred and fifty-three children and adolescents answered questionnaires and were clinically examined. The mean age of the follow-up in 2019 was 11.25 years old (±2.19). There was no increase in the incidence of SB (95% CI: 0.74-1.35). Children/adolescents had a 2.2 higher risk to present dental wear (95% CI: 1.89-2.60). SB at the follow-up was associated with the contextual variable, earache, erosion and awake bruxism.
CONCLUSIONS: In this population, children with SB remained with this behaviour and showed higher dental wear over the years.

Diagnosis of bruxism is challenging because not all contractions of the masticatory muscles can be classified as bruxism. Conventional methods for sleep bruxism detection vary in effectiveness. Some provide objective data through EMG, ECG, or EEG; others, such as dental implants, are less accessible for daily practice. These methods have targeted the masseter as the key muscle for bruxism detection. However, it is important to consider that the temporalis muscle is also active during bruxism among masticatory muscles. Moreover, studies have predominantly examined sleep bruxism in the supine position, but other anatomical positions are also associated with sleep. In this research, we have collected EMG data to detect the maximum voluntary contraction of the temporalis and masseter muscles in three primary anatomical positions associated with sleep, i.e., supine and left and right lateral recumbent positions. A total of 10 time domain features were extracted, and six machine learning classifiers were compared, with random forest outperforming others. The models achieved better accuracies in the detection of sleep bruxism with the temporalis muscle. An accuracy of 93.33% was specifically found for the left lateral recumbent position among the specified anatomical positions. These results indicate a promising direction of machine learning in clinical applications, facilitating enhanced diagnosis and management of sleep bruxism.

Sleep bruxism (SB) affects a considerable part of the population and is associated with neuroticism, stress, and anxiety in various studies. However, the causal mechanisms between neuroticism and SB have not been examined. Understanding the reasons for SB is important as understanding bruxism may allow improved comprehensive management of the disorders and comorbidities related to it. Previous studies on the association of risk factors to SB have provided important symptomatic insight but were mainly questionnaire based or limited in sample size and could not adequately assess causal relationships. The aim of this study was to elaborate the possible causal relationship of neuroticism as a risk factor for SB through a Mendelian randomization (MR) approach by combining questionnaires, registry data, and genetic information in large scale. We performed a two-sample MR study using instrumental genetic variants of neuroticism, including neuroticism subcategories, in the UK Biobank (n = 380,506) and outcome data of probable SB using FinnGen (n [cases/controls] = 12,297/364,980). We discovered a causal effect from neuroticism to SB (odds ratio [OR] = 1.38 [1.10-1.74], P = 0.0057). A phenotype sensitive to stress and adversity had the strongest effect (OR = 1.59 [1.17-2.15], P = 0.0028). Sensitivity analyses across MR methods supported a causal relationship, and we did not observe pleiotropy between neuroticism and SB (MR-Egger intercept, P = 0.87). Our findings are in line with earlier observational studies that connect stress and SB. Furthermore, our results provide evidence that neurotic traits increase the risk of probable SB.

Associations between obstructive sleep apnea (OSA) and sleep bruxism (SB) are the subject of discussion but have not been confirmed definitively. Therefore, the objective of this meta-analysis was to examine the relationship between OSA and SB. This systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed, Embase and Web of Science were screened up to February 2024. The risk of bias was assessed with the Joanna Briggs Institute tool. 2260 records were identified, but only 14 studies were included. The odds of SB presence in OSA did not differ from the control group (OR: 1.23, 95 % CI: 0.47-3.20). The chance of SB compared to controls also did not differ in mild OSA (OR: 1.56, 95 % CI: 0.76-3.18), in moderate OSA (OR: 1.51, 95 % CI: 0.77-2.94) and in severe OSA (OR: 1.50, 95 % CI: 0.68-3.29). Additionally, the odds of SB were not increased in moderate OSA in comparison to mild OSA (OR: 1.14, 95 % CI: 0.63-2.94), in severe OSA compared to moderate OSA (OR: 1.31, 95 % CI: 0.61-2.79) or in severe OSA compared to mild OSA (OR = 1.42, 95 % CI: 0.69-2.93). The presence of SB in OSA did not differ between genders (OR: 2.14, 95 % CI: 0.65-7.05). The quality of the major studies included is low; therefore, the noted lack of correlation between OSA and SB may require further research. The relationship between OSA and SB seems to be multi-faceted. Presented results should not exempt clinicians from exact diagnosis of concomitant sleep conditions in OSA subjects.

The objective of the current study was to evaluate the clinical utility of bruxism episode index in predicting the level of masticatory muscle pain intensity. The study involved adults (n = 220) recruited from the Outpatient Clinic of Temporomandibular Disorders at the Department of Experimental Dentistry, Wroclaw Medical University, during the period 2017-2022. Participants underwent medical interview and dental examination, focusing on signs and symptoms of sleep bruxism. The intensity of masticatory muscle pain was gauged using the Numeric Rating Scale. Patients identified with probable sleep bruxism underwent further evaluation through video-polysomnography. Statistical analyses included the Shapiro-Wilk test, Spearman\'s rank correlation test, association rules, receiver operating characteristic curves, linear regression, multivariate regression and prediction accuracy analyses. The analysis of correlation and one-factor linear regression revealed no statistically significant relationships between bruxism episode index and Numeric Rating Scale (p > 0.05 for all analyses). Examination of receiver operating characteristic curves and prediction accuracy indicated a lack of predictive utility for bruxism episode index in relation to masticatory muscle pain intensity. Multivariate regression analysis demonstrated no discernible relationship between bruxism episode index and Numeric Rating Scale across all examined masticatory muscles. In conclusion, bruxism episode index and masticatory muscle pain intensity exhibit no correlation, and bruxism episode index lacks predictive value for masticatory muscle pain. Clinicians are advised to refrain from employing the frequency of masticatory muscle activity as a method for assessing the association between masticatory muscle pain and sleep bruxism.

OBJECTIVE: The objective was the comparison of an occlusal device (OD), and sleep hygiene and progressive muscle relaxation (SH & PMR) on perceived stress and sleep bruxism activity (burst/episode and episode/hour) in participants with sleep bruxism.
METHODS: Sixty-six participants with self-reported sleep bruxism were selected and randomly allocated into two groups: OD group or SH & PMR group. Assessment of perceived stress and sleep bruxism activity were the primary outcomes. The Perceived Stress Scale-10 (PSS-10 scale) was used to measure perceived stress and bruxism episodes/hour and bursts/episode recorded by electromyography of masseter and temporalis. These outcomes were assessed at baseline, 1 month, 6 months, and 1 year. The paired t-test assessed changes in PSS-10 scores and sleep bruxism activity within the same group over different time points (baseline, 1 month, 6 months, and 1 year). The unpaired t-test compared scores between two groups (OD and SH & PMR) at each time point to evaluate intervention differences. The chi-square test compared gender distribution between both groups.
RESULTS: PSS-10 scores were found to decrease with the OD at 1 month and 6 months compared to baseline and SH & PMR at all subsequent follow-ups. This decrease was not statistically significant (p > 0.05) between the OD and SH & PMR groups at all follow-ups. OD and SH & PMR significantly reduced bruxism episodes/hour and bursts/episode at all follow-ups (p < 0.05). There were no adverse effects related to any intervention.
CONCLUSIONS: The OD and SH & PMR both effectively reduced PSS-10 scores over 6 months and significantly decreased bruxism episodes and bursts per episode. Both methods are safe and effective for managing sleep bruxism and reducing stress.

UNASSIGNED: Various biofeedback stimulation techniques for managing sleep bruxism (SB) have recently emerged; however, the effect of the successive application of vibratory feedback stimulation has not been clarified. This study aimed to elucidate the effect of vibration feedback stimulation via an oral appliance (OA) on SB.
UNASSIGNED: This prospective, single-arm, open-label intervention study included 20 participants diagnosed with \"definite\" SB who wore a specially designed OA for 98 nights at home. A force-based SB detection system triggered a vibrator attached to the OA. Vibratory stimulation was withheld during the first 3-week adaptation period (weeks 1-3), applied during the 9-week stimulation period (weeks 4-12), and withheld again during the post-stimulation period (weeks 13-14). The number and duration of SB events per hour of sleep were calculated based on piezoelectric signals recorded with the OA-based vibration feedback device and compared between weeks 3 and 4, 8, 12, and 14 and between weeks 12 and 14 using the Friedman test (post-hoc test with Bonferroni correction).
UNASSIGNED: The duration of SB events significantly decreased after vibratory stimulation (weeks 3 versus 4, 8, and 12: P < 0.001, P = 0.026, and P = 0.033, respectively) and then significantly increased upon cessation of vibratory stimulation after the stimulation period (weeks 12 versus 14: P < 0.001).
UNASSIGNED: Contingent vibratory stimulation through an OA-based vibration feedback device may suppress SB-related masticatory muscle activity continuously for 9 weeks and may be an effective alternative for managing SB.

BACKGROUND: Sleep-related bruxism (SB) is the habit of grinding or clenching the teeth during sleep, mediated by the non-peripheral central nervous system.
OBJECTIVE: The objectives of this cross-sectional study were to evaluate associations between SB, microarousals and oxyhaemoglobin desaturations and to compare the frequency of SB and microarousals in sleep stages, in an apnoeic population.
METHODS: Two hundred and forty individuals composed the sample, who underwent a single full-night polysomnography. Self-reports and clinical inspections were not considered for assessing SB. The polysomnographic assessment of SB was performed using electrodes placed on masseter muscles and chin. SB was defined as more than two events of rhythmic masticatory muscle activity per hour of sleep. Microarousals were considered when there were abrupt changes in electroencephalogram frequencies, without complete awakening, lasting from 3 to 15 s. Oxyhaemoglobin desaturations were defined as significant drops (≥3%) in basal oxygen saturations. With these data, SB, microarousals and oxyhaemoglobin desaturations were evaluated and submitted to statistical analysis.
RESULTS: Statistically significant differences were observed between bruxers and non-bruxers when comparing the rates of microarousals (p < .001) and oxyhaemoglobin desaturations (p = .038). There was a higher number of SB and microarousals in NREM (non-rapid eye movement) two sleep stage (p < 0.001). Bruxers had a greater risk of higher numbers of microarousals (OR = 1.023; p = .003), which did not occur for oxyhaemoglobin desaturations (OR = 0.998; p = .741).
CONCLUSIONS: A higher number of microarousals presents relationship with SB; associations between SB and oxyhaemoglobin desaturations remained inconclusive; higher frequency of SB and microarousals was observed in NREM 2 sleep stage.