Is sleep bruxism in obstructive sleep apnea only an oral health related problem?

BACKGROUND: The etiology of sleep bruxism in obstructive sleep apnea (OSA) patients is not yet fully clarified. This prospective clinical study aimed to investigate the connection between probable sleep bruxism, electromyographic muscle tone, and respiratory sleep patterns recorded during polysomnography. METHODS: 106 patients with OSA (74 males, 31 females, mean age: 56.1 ± 11.4 years) were divided into two groups (sleep bruxism: SB; no sleep bruxism: NSB). Probable SB were based on the AASM criteria: self-report of clenching/grinding, orofacial symptoms upon awakening, abnormal tooth wear and hypertrophy of the masseter muscle. Both groups underwent clinical examination for painful muscle symptoms aligned with Temporomandibular Disorders Diagnostic Criteria (DC/TMD), such as myalgia, myofascial pain, and headache attributed to temporomandibular disorder. Additionally, non-complaint positive muscle palpation and orofacial-related limitations (Jaw Functional Limited Scale-20: JFLS-20) were assessed. A one-night polysomnography with electromyographic masseter muscle tone (EMG) measurement was performed. Descriptive data, inter-group comparisons and multivariate logistic regression were calculated. RESULTS: OSA patients had a 37.1% prevalence of SB. EMG muscle tone (N1-N3, REM; P = 0.001) and the number of hypopneas (P = 0.042) were significantly higher in the sleep bruxism group. While measures like apnea-hypopnea-index (AHI), respiratory-disturbance-index (RDI), apnea index (AI), hypopnea-index (HI), number of arousals, and heart rate (1/min) were elevated in sleep bruxers, the differences were not statistically significant. There was no difference in sleep efficiency (SE; P = 0.403). Non-complaint masseter muscle palpation (61.5%; P = 0.015) and myalgia (41%; P = 0.010) were significant higher in SB patients. Multivariate logistic regression showed a significant contribution of EMG muscle tone and JFLS-20 to bruxism risk. CONCLUSION: Increased EMG muscle tone and orofacial limitations can predict sleep bruxism in OSA patients. Besides, SB patients suffer more from sleep disorder breathing. Thus, sleep bruxism seems to be not only an oral health related problem in obstructive apnea. Consequently, interdisciplinary interventions are crucial for effectively treating these patients. TRIAL REGISTRATION: The study was approved by the Ethics Committee of Philipps-University Marburg (reg. no. 13/22-2022) and registered at the "German Clinical Trial Register, DRKS" (DRKS0002959).

[Temporomandibular dysfunction and bruxism in patients with early rheumatoid arthritis and at-risk patients: a cross-sectional study]. / Temporomandibulaire disfunctie en bruxisme bij patiënten met vroege reumatoïde artritis en risicopatiënten: een cross-sectioneel onderzoek.

What is the prevalence of temporomandibular dysfunction in patients with early rheumatoid arthritis and individuals at risk of rheumatoid arthritis? 3 groups (of 50 participants each) were examined for a possible TMD diagnosis: 1. patients with early rheumatoid arthritis, 2. at-risk individuals, and 3. healthy controls. A possible association with bruxism, determined on the basis of self-reporting and clinical features, was also examined. At-risk patients had a higher prevalence of TMD pain diagnoses compared to healthy controls (p = 0.046). Within the early rheumatoid arthritis group, seronegative patients had a higher prevalence of TMD pain diagnoses than seropositive patients (p = 0.048). No further differences in the prevalence of TMD diagnoses were found between the groups. Participants with a TMD pain diagnosis were more often diagnosed with probable sleep bruxism than those without a TMD pain diagnosis. The prevalence of TMD pain is increased in individuals at risk of rheumatoid arthritis and seronegative early rheumatoid arthritis patients, and is associated with signs of bruxism.

Effects of respiratory exercises in sleep bruxism and associated obstructive sleep apnea: a double-blind, placebo-controlled randomized clinical trial.

PURPOSE: The aim of this study is to assess the effects of respiratory exercises (inspiratory and expiratory) in individuals with sleep bruxism (SB) and associated obstructive sleep apnea (OSA). METHODS: This is a double-blind, placebo-controlled randomized clinical trial including individuals with SB and associated respiratory events in OSA. Respiratory physical therapy was performed using inspiratory (Threshold® IMT), expiratory (Threshold® PEP) muscle training, and compared with a placebo group. A total of 30 daily respiratory cycles (inspiration and expiration) were performed five times a week for 12 weeks. Individuals were reassessed at two times, at baseline (T1) and after 12 weeks of training (T2) by means of the Pittsburgh Sleep Quality Index and Polysomnography. RESULTS: Awakening was significantly different (p ≤ 0.05) between the inspiratory group and placebo 12 weeks after respiratory physical therapy. The number of contractions of the masseter muscle differed between the inspiratory, expiratory, and placebo groups (p ≤ 0.05). CONCLUSION: Respiratory physical therapy for OSA improved awaking levels in 80 and 67% of the number of masseter muscle contractions, when compared to placebo. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (No. RBR-9F6JKM).

Decrypting the putative interrelation between sleep bruxism, masticatory muscle pain and sleep breathing disorders: Nosology and the role of hypoxia.

This commentary on sleep medicine explores whether the potential relationship between sleep bruxism (SB), masticatory muscle pain (MMP) and sleep breathing disorders (SBDs)contributes to improving the management of co-occurring conditions.The paper is divided into 2 sections: (1) reviewing the debate on SB nosology; and (2) based on the publications from the Martynowicz & Wieckiewicz research group, exploringthe role of intermittent hypoxia as a putative mechanism endotype that may link such co-occurrence among individuals for whom characteristics are not yet clear.

Efficiency of mixed and rigid occlusal stabilization splints: Randomized clinical trial.

Occlusal stabilization splints are the most common treatment for controlling the deleterious effects of sleep bruxism. This study aimed to evaluate the effectiveness of a low-cost, mixed occlusal splint (MOS) compared to that of a rigid splint. A randomized clinical trial was performed on 43 adults of both sexes with possible sleep bruxism and satisfactory dental conditions. They were divided into rigid occlusal splint (ROS) (n = 23) and MOS (n = 20) groups. Masticatory muscle and temporomandibular joint (TMJ) pain intensity (visual analog scale), quality of life (WHOQOL-BREF), indentations in the oral mucosa, anxiety, and depression (HADS), number of days of splint use, and splint wear were evaluated. All variables were evaluated at baseline (T0), 6 months (T6), and 12 months (T12) after splint installation (T0), and splint wear was evaluated at T6 and T12. Student's t-test, Mann-Whitney U test, non-parametric Friedman's analysis of variance for paired samples and pairwise multiple comparisons, Pearson's chi-square test, two-proportion z-test, non-parametric McNemar's and Cochran's Q, and Wilcoxon tests were used (p < 0.05). In both groups, there was a decrease in TMJ pain and pain intensity over time and improvements in the quality of life scores. At T6, there was a higher rate of splint wear in the MOS group than in the ROS group (p = 0.023). The MOS showed a higher rate of wear than the rigid splint but had similar results for the other variables. Therefore, the use of a mixed splint appears to be effective in controlling the signs and symptoms of sleep bruxism.

Influence of occlusal appliances on the masticatory muscle function in individuals with sleep bruxism: A systematic review and meta-analysis.

This systematic review answers the question: "Does occlusal appliance use influence masticatory muscle function of dentate individuals with sleep bruxism?". The literature search included six databases, grey literature, and manual search for articles. Randomized and non-randomized clinical trials were included comparing muscle function of sleep bruxers before and after receiving occlusal appliances. Risk of bias was assessed with risk of bias assessment for randomized and non-randomized clinical trials tool. Twelve studies, three represent randomized clinical trials, were included. Risk of bias was considered low, moderate, or serious. Meta-analyses indicated that soft and hard appliances did not influence muscle activity and bite force of bruxers. Qualitative analysis showed that occlusal appliance use did not influence masticatory performance and muscle volume. However, it was effective in reducing tongue force. Certainty of evidence was considered very low for muscle activity when evaluated with hard appliances, and for bite force evaluated with both appliance materials. Low certainty of evidence was observed for muscle activity with soft appliances. Based on the findings of this meta-analysis, occlusal appliances do not affect masticatory muscle function of sleep bruxers. Regardless of appliance material, the activity of masseter and temporal, and bite force of sleep bruxers was not influenced.

Influence of malocclusion on sleep bruxism and orofacial pain: data from a study in school children.

OBJECTIVES: This cross-sectional school-based study explored the influence of malocclusion on temporomandibular disorders (TMD) pain complaints, and whether this association would be mediated by sleep bruxism in a representative sample of 7- to 8-year-old children. METHODS: Path analysis estimated direct, indirect, and total effects of occlusal features on sleep bruxism and TMD pain in 7- to 8-year-old children. Occlusal features were assessed with Dental Aesthetic Index (DAI), orofacial pain complaints using the TMD pain screener, possible sleep bruxism based on self-reports, and probable sleep bruxism based on self-reports combined with clinical findings. Structural equation modeling analyzed data with confounding factors. RESULTS: From 580 participants, possible sleep bruxism was observed in 136 children (31.5%), probable sleep bruxism in 30 children (6.7%), and TMD pain complaints in 78 children (13.8%). Malocclusion had no direct effect on either possible sleep bruxism [standardized coefficient (SC) 0.000; p = 0.992], or TMD pain complaints (SC - 0.01; p = 0.740). When probable sleep bruxism was set as the mediator of interest, malocclusion did not directly affect probable sleep bruxism (SC 0.01; p = 0.766), nor TMD pain complaints (SC - 0.02; p = 0.515). A direct effect of probable sleep bruxism on TMD pain complaints was observed with an SC of 0.60 (p < 0.001). However, in neither case, malocclusion indirectly affected TMD pain complaints via bruxism. CONCLUSION: Malocclusion in 7- to 8-year-old children did not directly influence possible or probable sleep bruxism or TMD pain complaints. Instead, probable sleep bruxism was strongly associated with TMD pain complaints. CLINICAL SIGNIFICANCE: The impact of occlusal features on TMD pain complaints and bruxism has been a long-standing controversy in dentistry. However, the scientific literature linking this association may be inconsistent, mainly due to biased sample selection methods with inadequate consideration of confounders. Further research should try to identify additional risk factors for TMD pain in addition to probable sleep bruxism in children.

Self-reported bruxism in patients with post-traumatic stress disorder.

OBJECTIVE: The present study aimed to investigate the association between self-reported awake/sleep bruxism, and orofacial pain with post-traumatic stress disorder (PTSD). METHODS: A case-control study with a convenience sample was designed. Participants were recruited from a university-based Trauma Ambulatory. The diagnosis of PTSD was established through a clinical interview and the Structured Clinical Interview (SCID-I/P). Thirty-eight PTSD patients and 38 controls completed the Research Diagnostic Criteria for Temporomandibular Disorders Axis-II to categorize awake/sleep bruxism and orofacial pain. Following this, we performed a short clinical examination of the temporomandibular joint and extraoral muscles. RESULTS: Adjusted logistic regression analysis showed that awake bruxism was associated with PTSD (OR = 3.38, 95% CI = 1.01-11.27, p = 0.047). Sleep bruxism was not associated with any covariate included in the model. In a Poisson regression model, PTSD (IRR = 3.01, 95% CI = 1.38-6.55, p = 0.005) and the muscle pain/discomfort (IRR = 5.12, 95% CI = 2.80-9.36, p < 0.001) were significant predictors for current orofacial pain. CONCLUSIONS: PTSD was associated with self-reported awake bruxism and low-intensity orofacial pain. These conditions were frequent outcomes in patients previously exposed to traumatic events. CLINICAL RELEVANCE: We suggest including a two-question screening for bruxism in psychiatry/psychology interviews to improve under-identification and to prevent harmful consequences at the orofacial level.

Sleep bruxism: The past, the present, and the future-evolution of a concept.

BACKGROUND: The concept of sleep bruxism (SB) has evolved exponentially over the past several decades. Many theories and hypotheses have been proposed as to the definition, pathophysiology, and management of SB, from the early 1960s through the present. The role of peripheral factors, such as dental occlusion, in the pathogenesis of SB has been discarded. TYPES OF STUDIES REVIEWED: The authors searched several electronic databases (ie, PubMed, Google Scholar, Web of Science, Embase, and Ovid MEDLINE) for studies on bruxism. The search was conducted from January 1961 through May 2023 and yielded 4,612 articles, of which 312 were selected for comprehensive review after eliminating duplicates and nonfocused articles. RESULTS: There has been an evident progressive shift from the role of peripheral factors, such as dental occlusion, to more central factors, such as the involvement of a central pattern generator as well as the autonomic nervous system, in the genesis of bruxing movements. There is continued robust interest in the dental community to elucidate the contributing factors involved in SB. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The neurophysiology of SB appears to be leaning more toward central rather than peripheral factors. There is increasing evidence of the role of the autonomic nervous system, genetics, and comorbidities in the genesis of SB. The scientific literature seems to refute the role of dental occlusion in the causation of bruxing movements. As per the literature, there has been a paradigm shift in the definition and genesis of SB and its possible dental implications and management, which also highlights the need for succinct scientific studies in this regard.

Malocclusions, Sleep Bruxism, and Obstructive Sleep Apnea Risk in Pediatric ADHD Patients: A Prospective Study.

OBJECTIVES: Literature presents conflicting results regarding malocclusions, Obstructive Sleep Apnea (OSA) and sleep bruxism in children with ADHD. Aim of this study was to evaluate the prevalence of these parameters. METHODS: A prospective study was conducted on 40 consecutive ADHD children referred to the Paediatric Dentistry Unit of Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome. All subjects underwent an orthodontic examination and were screened for OSA and sleep bruxism. Data were compared to a sex- and aged-matched control group. RESULTS: Prevalence of high risk of OSA in children with ADHD was 62.5% compared to 10% in the control group (p < .00001). No differences were found in any of the occlusal variables examined between children with ADHD and controls (p > .05). An increased prevalence of sleep bruxism was observed in ADHD children (40%) compared to controls (7.5%) (p < .001). CONCLUSIONS: A higher prevalence of OSA risk and probable sleep bruxism were observed in ADHD patients compared with controls. No significant differences were observed in malocclusions d.

Oral biosciences: The annual review 2023.

BACKGROUND: The Journal of Oral Biosciences is dedicated to advancing and disseminating fundamental knowledge with regard to every aspect of oral biosciences. This review features review articles in the fields of "bone regeneration," "periodontitis," "periodontal diseases," "salivary glands," "sleep bruxism," and "Sjögren's syndrome." HIGHLIGHT: This review focuses on human demineralized dentin and cementum matrices for bone regeneration, oxidized low-density lipoprotein in periodontal disease and systemic conditions, the relationship between inflammatory mediators in migraine and periodontitis, phosphoinositide signaling molecules in the salivary glands, and the pathophysiologies of sleep bruxism and Sjögren's syndrome. CONCLUSION: The review articles featured in the Journal of Oral Biosciences have broadened the knowledge of readers regarding various aspects of oral biosciences. The current editorial review discusses the findings and significance of these review articles.

Prevalence of Bruxism in alcohol abusers: a systematic review conducted according to PRISMA guidelines and the cochrane handbook for systematic reviews of interventions.

BACKGROUND: Bruxism, a common oral parafunctional behavior characterized by the grinding or clenching of teeth, is a multifactorial condition with potentially detrimental effects on oral health and overall well-being. In recent years, there has been growing interest in understanding the relationship between bruxism and alcohol abuse, as both are prevalent issues that may share underlying factors and exacerbate each other. This systematic review, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, aims to evaluate the frequency of bruxism among individuals with alcohol abuse. METHODS: A comprehensive search of electronic databases, including PubMed, Lilacs, Scopus and Web of Science, will be conducted to identify relevant studies published up to the knowledge cutoff date in January 2023. The search strategy will include keywords related to bruxism, alcohol abuse, and their synonyms. Inclusion criteria will encompass original research studies, such as observational, cross-sectional, cohort, and case-control studies, as well as clinical trials, that examine the relationship between bruxism and alcohol abuse. Two independent reviewers will perform the study selection, data extraction, and quality assessment, with discrepancies resolved by consensus. RESULTS: The systematic review will present a summary of the identified studies, including the study design, characteristics of the study populations, and key findings related to the association between bruxism and alcohol abuse. The potential mechanisms underlying this relationship will also be explored. Subgroup analyses and the quality of evidence will be assessed. Finally, the implications of this association for clinical practice and further research will be discussed. CONCLUSIONS: This systematic review will contribute to a better understanding of the interplay between bruxism and alcohol abuse, shedding light on potential risk factors, mechanisms, and clinical implications. The findings may have significant implications for the prevention, management, and treatment of bruxism, particularly in individuals with a history of alcohol abuse.

Instrumental assessment of sleep bruxism: A systematic review and meta-analysis.

This systematic review and meta-analysis (MA) aimed to evaluate the diagnostic validity of portable electromyography (EMG) diagnostic devices compared to the reference standard method polysomnography (PSG) in assessing sleep bruxism. This systematic review was completed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement and was registered with PROSPERO prior to the accomplishment of the main search. Ten clinical studies on humans, assessing the diagnostic accuracy of portable instrumental approaches with respect to PSG, were included in the review. Methodological shortcomings were identified by QUADAS-2 quality assessment. The certainty of the evidence analysis was established by different levels of evidence according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. A meta-analysis of diagnostic test accuracy was performed with multiple thresholds per study applying a two-stage random effects model, using the thresholds offered by the studies and based on the number of EMG bruxism events per hour presented by the participants. Five studies were included. The MA indicated that portable EMG diagnostic devices showed a very good diagnostic capacity, although a high variability is evident in the studies with some outliers. Very low quality of evidence due to high risk of bias and high heterogeneity among included studies suggests that portable devices have shown high sensitivity and specificity when diagnosing sleep bruxism (SB) compared to polysomnography. The tests performed in the MA found an estimated optimal cut-off point of 7 events/hour of SB with acceptably high sensitivity and specificity for the EMG portable devices.

Comparative analysis of different types of occlusal splints for the management of sleep bruxism: a systematic review.

BACKGROUND: Sleep bruxism is a prevalent condition in dentistry practice, characterized by involuntary grinding or clenching of the teeth during sleep. Several therapies, including occlusal splints, have been used to manage sleep bruxism and temporomandibular disorders, including occlusal splints. This study aimed to compare the effectiveness of different occlusal splints in managing sleep bruxism. METHODS: The PICO framework encompasses the characterization of the population, intervention, comparison, and pertinent outcomes. A comprehensive and systematic literature review was conducted on PubMed, Scopus, and Google Scholar to identify grey literature. The search specifically targeted scientific studies published before September 20, 2023. The Cochrane Collaboration Risk of Bias Tool assessed the accuracy of the included Randomized Control Trials (RCTs). The modified Newcastle-Ottawa Scale assessed non-randomized studies. Data were systematically extracted, synthesized, and reported thematically. RESULTS: Out of the total of 808 articles that were evaluated, only 15 articles were found to meet the specified inclusion criteria. Adjustable splints, such as full-occlusion biofeedback splints, were more effective in reducing sleep bruxism episodes, improving patient-reported symptoms, and enhancing overall well-being. The impact of different occlusal sprints on electromyographic activity varies, and potential adverse effects should be considered individually. CONCLUSIONS: This review provides valuable insights into the effectiveness of occlusal splints in managing sleep bruxism. The results of this study indicate that occlusal splint therapy is a viable treatment approach for sleep bruxism.

Analysis of definite awake bruxism using a portable electromyography device.

PURPOSE: This study aimed to compare awake bruxism events between subjective and objective evaluations using a questionnaire survey and a modified portable electromyography (EMG) device, and to examine correlations between sleep quality and awake bruxism. METHODS: The Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and awareness of awake bruxism as clarified via interviews were conducted on 34 participants as subjective evaluations. The EMG device was used to record left temporal muscle activity for 6.5 h (from 09:00 to 15:30) and the number of awake bruxism episodes per hour. The participants were then classified into "bruxer" and "non-bruxer" groups based on the number of awake bruxism episodes. RESULTS: The mean number of awake bruxism episodes per hour was 33.6 ± 21.4, and 23% of the participants who reported having no awareness of awake bruxism in the interviews were defined as "bruxers" in the objective evaluations. In the bruxer group, positive correlations were found between the number of awake bruxism episodes and both ESS and PSQI scores. CONCLUSION: These findings suggest that objective measurements using a portable EMG device can increase the diagnostic accuracy for awake bruxism, and that sleep quality is a major risk factor for awake bruxism.

Classification of bruxism based on time-frequency and nonlinear features of single channel EEG.

BACKGROUND: In the classification of bruxism patients based on electroencephalogram (EEG), feature extraction is essential. The method of using multi-channel EEG fusing electrocardiogram (ECG) and Electromyography (EMG) signal features has been proved to have good performance in bruxism classification, but the classification performance based on single channel EEG signal is still understudied. We investigate the efficacy of single EEG channel in bruxism classification. METHODS: We have extracted time-domain, frequency-domain, and nonlinear features from single EEG channel to classify bruxism. Five common bipolar EEG recordings from 2 bruxism patients and 4 healthy controls during REM sleep were analyzed. The time domain (mean, standard deviation, root mean squared value), frequency domain (absolute, relative and ratios power spectral density (PSD)), and non-linear features (sample entropy) of different EEG frequency bands were analyzed from five EEG channels of each participant. Fine tree algorithm was trained and tested for classifying sleep bruxism with healthy controls using five-fold cross-validation. RESULTS: Our results demonstrate that the C4P4 EEG channel was most effective for classification of sleep bruxism that yielded 95.59% sensitivity, 98.44% specificity, 97.84% accuracy, and 94.20% positive predictive value (PPV). CONCLUSIONS: Our results illustrate the feasibility of sleep bruxism classification using single EEG channel and provides an experimental foundation for the development of a future portable automatic sleep bruxism detection system.

Standardised Tool for the Assessment of Bruxism.

OBJECTIVE: This paper aims to present and describe the Standardised Tool for the Assessment of Bruxism (STAB), an instrument that was developed to provide a multidimensional evaluation of bruxism status, comorbid conditions, aetiology and consequences. METHODS: The rationale for creating the tool and the road map that led to the selection of items included in the STAB has been discussed in previous publications. RESULTS: The tool consists of two axes, specifically dedicated to the evaluation of bruxism status and consequences (Axis A) and of bruxism risk and etiological factors and comorbid conditions (Axis B). The tool includes 14 domains, accounting for a total of 66 items. Axis A includes the self-reported information on bruxism status and possible consequences (subject-based report) together with the clinical (examiner report) and instrumental (technology report) assessment. The Subject-Based Assessment (SBA) includes domains on Sleep Bruxism (A1), Awake Bruxism (A2) and Patient's Complaints (A3), with information based on patients' self-report. The Clinically Based Assessment (CBA) includes domains on Joints and Muscles (A4), Intra- and Extra-Oral Tissues (A5) and Teeth and Restorations (A6), based on information collected by an examiner. The Instrumentally Based Assessment (IBA) includes domains on Sleep Bruxism (A7), Awake Bruxism (A8) and the use of Additional Instruments (A9), based on the information gathered with the use of technological devices. Axis B includes the self-reported information (subject-based report) on factors and conditions that may have an etiological or comorbid association with bruxism. It includes domains on Psychosocial Assessment (B1), Concurrent Sleep-related Conditions Assessment (B2), Concurrent Non-Sleep Conditions Assessment (B3), Prescribed Medications and Use of Substances Assessment (B4) and Additional Factors Assessment (B5). As a rule, whenever possible, existing instruments, either in full or partial form (i.e. specific subscales), are included. A user's guide for scoring the different items is also provided to ease administration. CONCLUSIONS: The instrument is now ready for on-field testing and further refinement. It can be anticipated that it will help in collecting data on bruxism in such a comprehensive way to have an impact on several clinical and research fields.

Self-reported sleep bruxism and mortality in 1990-2020 in a nationwide twin cohort.

BACKGROUND: The association of sleep bruxism with mortality has not been studied. OBJECTIVES: Altogether 12 040 subjects from the nationwide Finnish twin cohort were included in the analyses. We examined whether self-reported sleep bruxism is associated with increased risk of mortality, and if so, whether the effect is independent of known common risk factors. The time span of the follow-up was 30 years. METHODS: Cox proportional hazards regression models (Hazard Ratios and their 95% Confidence Intervals) adjusted by age, sex and covariates were used to assess the effect of baseline bruxism status in 1990 on future mortality in 1990-2020. RESULTS: The risk of mortality among all participants (n = 12 040), independent of missing covariates and adjusted by age and sex, was 40% higher in weekly bruxers than in never bruxers (HR 1.40, 95% CI 1.16-1.68, p < .001). However, when adjusted by all studied covariates, (n = 11 427) the risk was no longer observed (HR 1.04, 95% CI 0.86-1.25, p = .717). Despite the overall lack of between bruxism and mortality after adjustment for covariates, we examined the cause-specific risks for major cause-of-death groups. There were no substantial associations of weekly bruxism with major disease outcomes by the fully adjusted hazard ratios for them. CONCLUSION: Bruxism does not kill-in line with its definition of being rather a behaviour (with all its phenotypes) than a disease.

The bruxism screener (BruxScreen): Development, pilot testing and face validity.

BACKGROUND: To assess awake and sleep bruxism, the Standardised Tool for the Assessment of Bruxism (STAB) is currently being developed. The STAB will be a comprehensive tool for the detailed assessment of bruxism behaviour itself as well as of its possible consequences, causes, and comorbid conditions. OBJECTIVE: Since the STAB cannot fully meet the 'A4 principle' for a bruxism assessment tool, i.e., being Accurate (reliable and valid), Applicable (feasible), Affordable (cost-effective), and Accessible (suitable for everyday clinical use), the Bruxism Screener (BruxScreen) has been developed to be used in large-scale epidemiological research projects and, especially, in general, dental practices. METHODS: The BruxScreen consists of two parts: a questionnaire (BruxScreen-Q) to be completed by patients, and a clinical assessment form (BruxScreen-C) to be completed by dentists. RESULTS: This paper describes the development of the BruxScreen and provides the outcomes of the pilot testing phase and the face validity assessment (i.e. that the first impressions of the tool indicate that it adequately reflects the construct to be measured). CONCLUSION: The resulting BruxScreen is considered ready for more profound psychometric testing in the general dental setting.

Correlations between sleep architecture and sleep-related masseter muscle activity in children with sleep bruxism.

BACKGROUND: Sleep bruxism (SB) occurring during No-REM (nREM) sleep and increase in microarousals per hour have been described in adults, but not in children. OBJECTIVE: To assess the correlation between sleep architecture and masseter muscle activity related to sleep bruxism (SB/MMA) in children. MATERIALS AND METHODS: Forty-three children aged 7-12 years (mean age: 9.4 ± 1.3) with confirmed SB underwent a two-night polysomnographic (PSG) study in a sleep laboratory, for accommodation (first night) and data collection (second night). Data on sleep architecture (total sleep duration (TSD), sleep efficiency (SE), sleep onset latency (SOL), REM and nREM sleep duration and proportion and microarousals/hour during REM and nREM sleep) and episodes/hour of SB/MMA were recorded. Single and multiple-variable linear regression analyses were performed to assess the correlation between data on sleep architecture (predictors) and SB/MMA (dependent variable). RESULTS: Shorter TSD, REM and nREM stage 1 sleep duration, longer SOL and more microarousals/hour during REM and nREM sleep were found to be positive predictors of SB/MMA in children in the multiple-variable regression analysis (R2  = 0.511). CONCLUSION: Within the limitations of this study, it can be concluded that SB/MMA is correlated with altered sleep architecture in children (shorter total sleep duration (TSD), shorter nREM and REM sleep and higher microarousals during REM and nREM sleep). Nevertheless, the clinical significance of these findings need to be demonstrated in future studies.