Is bruxism a disorder or a behaviour? Rethinking the international consensus on defining and grading of bruxism

Oral behaviors and anxiety are significant predictors of jaw function limitation in patients with anterior disc displacement without reduction

OBJECTIVE

We aimed to describe jaw function characteristics in patients with anterior disc displacement without reduction (ADDWoR) using the jaw function limitation scale (JFLS), and to investigate the effects of biopsychosocial risk factors on limited jaw function.

DESIGN

In this cross-sectional study of 636 patients with ADDWoR (females, 568; males, 68), we used the JFLS to assess jaw function. Behavioral, psychological, sociodemographic, and biomedical data were collected. Multivariate logistic regression analysis was used to determine risk factors affecting limited jaw function. A receiver operating characteristic curve was used to evaluate the predictive effect of these risk factors.

RESULTS

ADDWoR-associated limitations included restricted jaw mobility and mastication, which exceeded median global functional limitations scale scores, especially mouth opening to bite an apple and chewing tough food. Females had greater limitations in jaw mobility, verbal and emotional communication, and overall. Multivariate logistic regression analysis findings indicated that oral behaviors, anxiety, sex, pain intensity, and maximal mouth opening (MMO) were predictive of limited jaw function (area under the curve, 72 %).

CONCLUSION

Patients with ADDWoR reported mastication and jaw mobility restrictions, with females having more pronounced limitations, and specific risk factors identified as significant predictors of jaw function limitations. Along with pain relief and improvement in MMO, appropriate psychological counseling and oral behavioral correction facilitates recovery of jaw function in such patients.

Comparative evaluation of salivary melatonin levels in patients with bruxism: a case-control study

Aim: To examine whether there is any difference in the levels of salivary melatonin between bruxism and nonbruxism groups and to compare the stress and anxiety levels between the two groups.Materials & methods: Patients meeting the probable bruxism criteria according to the International Consensus on the Assessment of Bruxism Criteria were included in the bruxism group. The salivary melatonin concentrations of both groups were measured using an ELISA kit. To determine the relationship between stress and bruxism, the State-Trait Anxiety Inventory (STAI) test was used.Results: The bruxism group had a significantly lower night-time salivary melatonin level than the control group (p < 0.05). No significant difference was determined between the bruxism group and the control group in respect of the STAI-T scores (p > 0.05).Conclusion: The study findings revealed a strong relationship between a low melatonin level and bruxism.

Relationship between sleep bruxism and obstructive sleep apnoea: A population-based survey

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.

Effects of orthodontic aligners on the ecological report of awake bruxism

BACKGROUND

The demand for orthodontic treatment with aligners has recently increased, but their effects on awake bruxism (AB) behaviours have to be evaluated yet.

OBJECTIVES

This investigation assessed if aligners can affect oral behaviours (i.e. tooth contact, teeth clenching, teeth grinding and mandible bracing) that are related with the AB spectrum.

METHODS

The investigation was performed in a sample of 32 consecutively recruited healthy adult patients who required orthodontic treatment. The study protocol involved three different sessions of 1-week monitoring without aligners, with passive aligners and with active aligners, respectively. All patients underwent an orthodontic treatment with aligners and used a smartphone-based application for a real-time report (i.e. ecological momentary assessment [EMA]) of their AB behaviours. Recording time was set from 8.00 to 12.30 and from 14.30 to 22.00. Analysis of variance (ANOVA) was used to compare the average reported frequency for each activity within and between the different sessions. The coefficient of variation (CV) was assessed to evaluate daily fluctuations within the 7 days monitoring periods.

RESULTS

The average reported frequency of the relaxed condition was 64.9%, 63.0% and 60.0% during the sessions without aligners, with passive aligners and with active aligners, respectively. ANOVA showed no significant differences in any of the AB behaviours within (i.e. between 7 days of evaluation) and between the monitoring sessions (i.e. before orthodontic treatment, with passive aligners, with active aligners). No sex differences were detected, except for the 'tooth contact' report that showed a higher frequency in females.

CONCLUSION

The impact of our results in the orthodontic field is not negligible; clinicians can find support for the hypothesis that from a global point of view, wearing or not wearing aligners (passive and/or active) does not influence the frequency of AB behaviours at the short term.

Examination of Information Quality on Public Instagram Profiles Regarding Botulinum Toxin for Bruxism: A Study in São Paulo State, Brazil

Background

Currently, social media emerges as a swift and efficient channel for disseminating knowledge in dentistry; however, it is imperative to assess whether this information aligns with scientific evidence. This study aims to evaluate the quality of information found on public Instagram profiles in São Paulo State, Brazil, regarding the utilization of botulinum toxin (BTx) for bruxism treatment.

Material and Methods

The data were categorized into three qualitative groups: information pertaining to bruxism diagnosis, treatment options for bruxism, and the application of BTx for bruxism. Following the selection of pertinent publications, 50 public profiles were included in the analysis. The publications were assessed utilizing the Global Quality Scale (GQS).

Results

A total of 20,546 posts were tallied across the 50 profiles, with 230 relating to bruxism diagnosis, 166 discussing bruxism treatment options, and 78 mentioning the use of BTx for bruxism. Of these 78 posts addressing BTx for bruxism, 61% did not align with current scientific references, while 39% did. GQS analysis disclosed predominantly "poor quality" content (GQS = 2).

Conclusions

It is concluded that the themes of bruxism and BTx are frequently broached on public Instagram profiles, yet the quality of the available information is generally subpar and often lacks scientific substantiation. Key words:Botulinum Toxins, Type A; Bruxism; Online Social Networking; Sleep Bruxism.

Analysis of risk factors and interactions for pain in temporomandibular disorder: A cross-sectional study

BACKGROUND

Risk factors for temporomandibular disorder (TMD) pain remain unclear.

OBJECTIVES

This study aimed to identify risk factors for TMD pain using a biopsychosocial model and to investigate interactions between potential risk factors-oral behaviours (OBs), psychological factors and sleep quality-and their direct and indirect effects on TMD pain.

METHODS

This was a cross-sectional study of 488 patients with TMDs (422 women; 30.8 ± 9.4 years). Pain was assessed using the Numerical Rating Scale. Demographic, behavioural, psychological and biomedical data were collected through clinical examination, face-to-face interviews and questionnaires. Multiple linear regression analysis was used to identify factors associated with TMD pain. Mediation and moderation analysis were used to evaluate interactions between variables. Significant mediation ('0' not included in the 95% confidence interval (CI)) and moderation (p < .05) effects on TMD pain were identified.

RESULTS

Marital status, diagnosis subgroup, previous medication use, depression and sleep quality were significant risk factors for TMD pain (p < .05). Significant mediation effects were observed as follows: depression and sleep quality mediated the association between OBs and pain; sleep quality mediated the association between somatization, depression, anxiety and pain; and depression mediated the association between sleep quality and pain (all 95% CI did not contain '0').

CONCLUSIONS

(1) Marital status, diagnosis subgroup, previous medication use, depression and sleep quality were associated with TMD pain. (2) OBs can exacerbate pain by promoting depression and reducing sleep quality. Psychological factors and sleep quality can interact to exacerbate pain.

Effects of vibratory feedback stimuli through an oral appliance on sleep bruxism: A 14-week intervention trial

Background/purpose

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.

Materials and methods

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).

Results

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).

Conclusion

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.

Bruxism, temporomandibular disorders, and headache-a narrative review of correlations and causalities

ABSTRACT

The co-occurrence of bruxism, temporomandibular disorders (TMDs), and headache is common in patients. However, there is conflicting evidence regarding whether this association is simply a result of their high prevalence or whether there are indeed causal relationships. This review provides an overview of the current state of research while taking into account the controversies surrounding research methods, particularly in definitions and diagnostic standards. Bruxism-defined as repetitive jaw muscle activity during sleep or wakefulness-is not a painful disorder but may-particularly in co-occurrence with TMD-worsen pre-existing headache. It seems important to differentiate between sleep and awake bruxism because of different impact on pathophysiological processes in different primary headache disorders such as migraine and tension-type headache. Temporomandibular disorder is a heterogenous entity with both myofascial and arthrogenous types of pain in addition to nonpainful disorders. Research suggests a correlation between TMD pain and migraine, as well as between awake bruxism and tension-type headache. However, psychosocial factors may act as confounders in these relationships. Determining causality is challenging because of the limited number of experimental and clinical studies conducted on this topic. The main finding is an apparent lack of consensus on the definition and assessment criteria for bruxism. Treatment wise, it is important to differentiate all 3 conditions because treatment of one condition may have an effect on the other 2 without proving causality. For future research, it is crucial to establish greater consistency and applicability in diagnostic procedures and definitions. In addition, more experimental and clinical studies investigating the question of causality are needed.

Effects of orthodontic aligners on 24-hour masseter muscle activity: a multiple-day electromyographic study

OBJECTIVE

This study aimed to assess the effects of aligners on masseter muscle activity by using an electromyographic device in the home environment.

METHODS

The study was performed on healthy patients who required orthodontic treatment. Three different 24 h-EMG recording sessions were performed in different conditions: without aligners, with passive aligners, and with active aligners. The non-functional MMA work index (nfMMA-WI) and the non-functional MMA time index (nfMMA-TI) for both awake and sleep hours were assessed. ANOVA test was used to compare the average activity during the three recording conditions.

RESULTS

On average, a total recording time of 204.7 ± 7.9 hours were provided for each patient. For most patients, ANOVA test showed an absence of significant differences between the recording sessions.

CONCLUSIONS

The impact of our results is not negligible: clinicians can find remarkable support to the hypothesis that the use of aligners affects the MMA only in a minority of subjects.

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.

Comparison of ultrasonography-based masticatory muscle thickness between temporomandibular disorders bruxers and temporomandibular disorders non-bruxers

To compare masticatory muscle thickness in patients with temporomandibular disorders (TMDs) during rest and clenching, and by body position, using ultrasonography. This prospective study included 96 patients with TMD (67 females, 29 males; mean age: 40.41 ± 17.88 years): group 1, comprising 66 patients with TMD without bruxism (TMD_nonbruxer), and group 2, comprising 30 patients with concurrent TMD and bruxism (TMD_bruxer). In patients with TMD, bruxism was correlated with the presence of tinnitus, muscle stiffness, sleep problems, psychological stress, and restricted mouth opening. The masseter muscle significantly thickened during clenching (11.16 ± 3.03 mm vs 14.04 ± 3.47 mm, p < 0.001), whereas the temporalis muscle showed no significant increase in thickness from resting to clenching in an upright position (7.91 ± 1.98 vs 8.39 ± 2.08, p = 0.103). Similarly, during clenching in the supine position, the masseter muscle was significantly thicker compared with rest (11.24 ± 2.42 vs 13.49 ± 3.09, p < 0.001), but no significant difference was observed in temporal muscle thickness (8.21 ± 2.16 vs 8.43 ± 1.94, p = 0.464). In comparison between two groups, the average thickness of the masseter muscle was greater among TMD_bruxers than among TMD_nonbruxers in both the upright and supine positions (all p < 0.05). In the generalized lineal model, female sex (B = - 1.018, 95% confidence interval [CI] - 1.855 to - 0.181, p = 0.017) and bruxism (B = 0.868, 95% CI 0.567 to 1.169, p = 0.048) significantly predicted changes in masseter muscle thickness. Female sex (B = - 0.201, 95% CI - 0.299 to - 0.103, p = 0.011), increased age (B = - 0.003, 95% CI - 0.005 to 0.000, p = 0.038), and muscle stiffness (B = - 1.373, 95% CI - 2.369 to - 0.376, p = 0.007) were linked to decreased temporal muscle thickness. Comparing TMD nonbruxer and bruxer muscle thicknesses in upright and supine positions revealed significant increased thickness in the masseter muscle during clenching but not in the temporalis muscle. Masseter muscle thickness varied significantly by sex, body position, and resting/clenching, notably influenced by bruxism. These findings emphasize the relevance of these factors in clinical examinations of patients with TMD.

Association Between Oral Behaviors and Painful Temporomandibular Disorders: A Cross-Sectional Study in the General Population

Background

Studies have reported correlations between various oral behaviors and painful temporomandibular disorders (TMD), yet comprehensive research on the independent effects of each oral behavior within the general population remains sparse.

Objective

This cross-sectional study aimed to investigate the association between painful TMD (PT) and various oral behaviors in general population.

Methods

A questionnaire survey was conducted with participants to collect data encompassing demographic characteristics, eight specific oral behaviors, and the 5 major TMD symptoms(5Ts) checklist. Participants were categorized into PT and non-PT (NPT) groups based on their responses to the 5Ts checklist. Those reporting TMJ/facial pain or headaches were assigned to the PT group, while all other participants constituted the NPT group. Both univariate and multivariate logistic regression analyses were employed to evaluate the association between individual oral behavior and the presence of PT, controlling for demographic confounders including age, sex, systemic diseases, and dental treatments history.

Results

A total of 441 valid questionnaires were received, including 156 males and 285 females. The prevalence of PT was identified to be 33.33%, with 61.00% of participants engaging in one or more types of oral behaviors. Each oral behavior was more frequently reported in the PT group compared to the NPT group. The univariate logistic regression analysis identified positive correlations between all eight oral behaviors and PT. In the multivariate logistic regression analysis, these associations persisted after adjustment for demographic confounders including age, sex, history of systemic diseases and dental treatments (P<0.01). The behaviors most strongly associated with PT were "Hold or jut jaw forward/to the side" (OR:4.478), "Hold, tighten or tense muscles without clench" (OR:3.343) and "Hold jaw in rigid or tense position" (OR:3.209).

Conclusion

The presence of oral behaviors has significant association with PT. Individuals exhibiting multiple oral behaviors are more likely to experience PT. Additional studies are needed to clarify the effects of reducing oral behaviors on pain-related symptoms.

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.

Bruxism and oro-facial pain not related to temporomandibular disorder conditions: Comorbidities or risk factors?

INTRODUCTION

Bruxism has historically been of particular interest to the field of dentistry, primarily due to the inferred damage it may cause to the dentition and supporting periodontal structures. The definition of bruxism itself has undergone multiple changes over time. In addition, the effects of bruxism as it relates to oro-facial pain conditions has remained a debatable topic.

PURPOSE

To review the available literature relating to bruxism and non-temporomandibular disorder (TMD) pain conditions.

METHODS

A literature search was conducted with the assistance of an expert librarian. The following databases were reviewed: PubMed, MEDLINE, EMBASE and Google Scholar. For additional references, articles were also retrieved by hand search from the selected papers. Any articles that were not published in English, or the focus were related to temporomandibular disorders were excluded.

CONCLUSIONS

While bruxism and certain headache conditions do tend to occur together frequently, evidence relating to any clear common pathophysiological mechanism has yet to be fully elucidated. Robust evidence as it relates to the relationship between bruxism and other non-TMD oro-facial pains is also lacking.

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.

Research routes on awake bruxism metrics: Implications of the updated bruxism definition and evaluation strategies

BACKGROUND

With time, due to the poor knowledge on it epidemiology, the need to focus on awake bruxism as a complement of sleep studies emerged.

OBJECTIVE

In line with a similar recent proposal for sleep bruxism (SB), defining clinically oriented research routes to implement knowledge on awake bruxism (AB) metrics is important for an enhanced comprehension of the full bruxism spectrum, that is better assessment and more efficient management.

METHODS

We summarised current strategies for AB assessment and proposed a research route for improving its metrics.

RESULTS

Most of the literature focuses on bruxism in general or SB in particular, whilst knowledge on AB is generally fragmental. Assessment can be based on non-instrumental or instrumental approaches. The former include self-report (questionnaires, oral history) and clinical examination, whilst the latter include electromyography (EMG) of jaw muscles during wakefulness as well as the technology-enhanced ecological momentary assesment (EMA). Phenotyping of different AB activities should be the target of a research task force. In the absence of available data on the frequency and intensity of wake-time bruxism-type masticatory muscle activity, any speculation about the identification of thresholds and criteria to identify bruxers is premature. Research routes in the field must focus on the improvement of data reliability and validity.

CONCLUSIONS

Probing deeper into the study of AB metrics is a fundamental step to assist clinicians in preventing and managing the putative consequences at the individual level. The present manuscript proposes some possible research routes to advance current knowledge. At different levels, instrumentally based and subject-based information must be gathered in a universally accepted standardised approach.

The development of the Standardised Tool for the Assessment of Bruxism (STAB): An international road map

This paper summarises the background reasoning and work that led to the selection of the items included in the Standardised Tool for the Assessment of Bruxism (STAB), also introducing the list of items. The instrument is currently being tested for face validity and on-field comprehension. The underlying premise is that the different motor activities included in the bruxism spectrum (e.g. clenching vs. grinding, with or without teeth contact) potentially need to be discriminated from each other, based on their purportedly different aetiology, comorbidities and potential consequences. Focus should be on a valid impression of the activities' frequency, intensity and duration. The methods that can be used for the above purposes can be grouped into strategies that collect information from the patient's history (subject-based), from the clinical assessment performed by an examiner (clinically based) or from the use of instruments to measure certain outcomes (instrumentally based). The three strategies can apply to all aspects of bruxism (i.e. status, comorbid conditions, aetiology and consequences). The STAB will help gathering information on many aspects, factors and conditions that are currently poorly investigated in the field of bruxism. To this purpose, it is divided into two axes. Axis A includes the self-reported information on bruxism status and potential consequences (subject-based report) together with the clinical (examiner report) and instrumental assessment (technology report). Axis B includes the self-reported information (subject-based report) on factors and conditions that may have an etiological or comorbid role for bruxism. This comprehensive multidimensional assessment system will allow building predictive model for clinical and research purposes.

Prevalence of bruxism in down syndrome patients: A systematic review and meta-analysis

BACKGROUND

Bruxism is a parafunctional activity characterised by grinding or clenching of teeth and is a common oral health concern in individuals with down syndrome (DS). Understanding the prevalence of bruxism in this population is crucial for developing effective management strategies. This systematic review and meta-analysis is aimed to investigate the prevalence of bruxism among individuals with DS and explore its association with other oral health issues.

METHODS

A comprehensive search was conducted across multiple electronic databases to identify relevant studies. Cross-sectional and observational studies were included. Data on bruxism prevalence and associated factors were extracted, and a meta-analysis was performed using both fixed-effects (FE) and random-effects (RE) models of MedCalc software. Heterogeneity among studies was assessed using I2 statistics. New Castle-Ottawa Scale was used to evaluate methodological quality of the included studies.

RESULTS

Eight studies met the pre-defined inclusion criteria and were included in the analysis. Seven studies used a questionnaire to assess bruxism. The pooled proportion estimate for occurrence of DS across the included studies was found to be 0.33 (95% CI: 0.22-0.45) as per the RE model and 0.35 (95% CI: 0.31-0.450) as per FE model in the quantitative analysis. All studies exhibited good methodological quality.

CONCLUSION

This systematic review and meta-analysis provide evidence of a significant prevalence of bruxism among individuals with DS. The findings highlight the association of bruxism with other oral health issues and specific chromosomal abnormalities. Comprehensive oral health assessments, including diagnostic procedures like Polysomnography, are essential for addressing the unique oral health needs of individuals with DS. Further studies are recommended with a valid tool for the diagnosis. Early interventions and management strategies need to be tailored to this population, considering the multifaceted nature of oral health concerns in individuals with DS.

Diagnostic Accuracy of a Portable Electromyography and Electrocardiography Device to Measure Sleep Bruxism in a Sleep Apnea Population: A Comparative Study

BACKGROUND

The gold standard for diagnosing sleep bruxism (SB) and obstructive sleep apnea (OSA) is polysomnography (PSG). However, a final hypermotor muscle activity often occurs after apnea episodes, which can confuse the diagnosis of SB when using portable electromyography (EMG) devices. This study aimed to compare the number of SB episodes obtained from PSG with manual analysis by a sleep expert, and from a manual and automatic analysis of an EMG and electrocardiography (EKG) device, in a population with suspected OSA.

METHODS

Twenty-two subjects underwent a polysomnographic study with simultaneous recording with the EMG-EKG device. SB episodes and SB index measured with both tools and analyzed manually and automatically were compared. Masticatory muscle activity was scored according to published criteria. Patients were segmented by severity of OSA (mild, moderate, severe) following the American Academy of Sleep Medicine (AASM) criteria. ANOVA and the Bland-Altman plot were used to quantify the agreement between both methods. The concordance was calculated through the intraclass correlation coefficient (ICC).

RESULTS

On average, the total events of SB per night in the PSG study were (8.41 ± 0.85), lower than the one obtained with EMG-EKG manual (14.64 ± 0.76) and automatic (22.68 ± 16.02) analysis. The mean number of SB episodes decreases from the non-OSA group to the OSA group with both PSG (5.93 ± 8.64) and EMG-EKG analyses (automatic = 22.47 ± 18.07, manual = 13.93 ± 11.08). However, this decrease was minor in proportion compared to the automatic EMG-EKG analysis mode (from 23.14 to 22.47). The ICC based on the number of SB episodes in the segmented sample by severity degree of OSA along the three tools shows a moderate correlation in the non-OSA (0.61) and mild OSA (0.53) groups. However, it is poorly correlated in the moderate (0.24) and severe (0.23) OSA groups: the EMG-EKG automatic analysis measures 14.27 units more than PSG. The results of the manual EMG-EKG analysis improved this correlation but are not good enough.

CONCLUSIONS

The results obtained in the PSG manual analysis and those obtained by the EMG-EKG device with automatic and manual analysis for the diagnosis of SB are acceptable but only in patients without OSA or with mild OSA. In patients with moderate or severe OSA, SB diagnosis with portable electromyography devices can be confused due to apneas, and further study is needed to investigate this.

Dental Implant Treatment in Bruxers: A Case Report and Literature Review

This case report presents a literature review and a case report of a full-mouth implant rehabilitation for a 65-year-old woman with a history of Bruxism. The patient's oral condition showed dentition with severe occlusal wear, extensive dental work, and missing teeth replaced with bridges and implants. The existing dental work was failing due to recurrent caries and the mechanical failure of long-span bridges. The unique aspect of the treatment presented in this report is the management of existing osseointegrated implants of different systems with different platform designs, which adds to the treatment's complexity. The existing implants were incorporated into the planned treatment, and other implants were added to support maxillary zirconia and mandibular hybrid full-arch prostheses. After 2 years of function, extensive wear was evident on the milled acrylic, even though an occlusal guard was used. New acrylic teeth were processed using the same milled titanium bar of the mandibular hybrid prosthesis, and the occlusal surfaces of the acrylic teeth were protected with gold onlays. The patient is seen regularly for maintenance every 6 months with no further complications. Careful evaluation, planning, and treatment execution are paramount in managing patients with a history of bruxism. Patients should be prepared and informed about possible mechanical failure and seen regularly for maintenance.

Neural Correlates of Tooth Clenching in Patients with Bruxism and Temporomandibular Disorder-Related Pain

AIMS

To measure brain activity in patients with bruxism and temporomandibular disorder (TMD)-related pain in comparison to controls using functional magnetic resonance imaging (fMRI) and to investigate whether modulations in jaw clenching led to different pain reports and/or changes in neural activity in motor and pain processing areas within and between both groups.

METHODS

A total of 40 participants (21 patients with bruxism and TMD-related pain and 19 healthy controls) performed a tooth-clenching task while lying inside a 3T MRI scanner. Participants were instructed to mildly or strongly clench their teeth for brief periods of 12 seconds and to subsequently rate their clenching intensity and pain experience after each clenching period.

RESULTS

Patients reported significantly more pain during strong clenching compared to mild clenching. Further results showed significant differences between patients and controls in activity in areas of brain networks commonly associated with pain processing, which were also correlated with reported pain intensity. There was no evidence for differences in activity in motor-related areas between groups, which contrasts with findings of previous research.

CONCLUSIONS

Brain activity in patients with bruxism and TMD-related pain is correlated more with pain processing than with motoric differences.

Sleep bruxism in children, from evidence to the clinic. A systematic review

Objectives

The present paper aims to systematically review the literature published from 2015 to 2023 on bruxism in children with the aim to compilate the best available evidence.

Materials and Methods

A systematic search in the National Library of Medicine's PubMed, Medline (EBSCO), SCOPUS, and Google Scholar databases was performed to identify all studies on humans assessing genetic, biopsychosocial, and sleep factors assessed with any different approach for sleep bruxism (SB) in children and its interventions. The selected articles were assessed independently by the two authors according to a structured reading of the article's format (PICO). The quality of the articles was evaluated using Quality Assessments Tool for Experimental Bruxism Studies (Qu-ATEBS) and the JBI critical appraisal tools.

Results

A total of 16 articles were included for discussion in the review and grouped into questionnaire/parental-report (n = 7), SB assessment through parental report of SB and clinical examination (n = 4), and instrumental assessment (n = 5) studies. The total quality scores evaluated with STROBE and Qu-ATEBS were high for all included papers. However, in general, there was no control of bias strategies and there was no control group in the intervention studies.

Conclusions

Investigations based on self-report, clinical, and instrumental bruxism assessment showed a positive association with genetics, quality of life aspects (school and emotional functions and overuse of screen-time), mother anxiety and family conformation, diet, alteration in sleep behaviors and architecture, and sleep breathing disorders. Additionally, the literature presents options to increase airway patency and, thus, reduce the occurrence of SB. Tooth wear was not found to be a major sign of SB in children. However, methods of SB assessment are heterogeneous and hamper a reliable comparison of the results.

Dental practitioner approaches to bruxism: Preliminary findings from the national dental practice-based research network

OBJECTIVE

Bruxism is a repetitive masticatory muscle activity. This study investigates dental practitioners' approaches to bruxism assessment and treatment in practices.

METHODS

A brief 5 question questionnaire ("Quick Poll") on bruxism was conducted.

RESULTS

A total of 397 practitioners responded. More than half (55%) initiated treatment for bruxism on one to three patients per month. The majority believed that stress (97%) and sleep patterns (82%) affected bruxism in their patients. Interestingly, 96% offered an occlusal guard/appliance and 46% made occlusal adjustments.

CONCLUSION

This study highlights inconsistencies in practitioner approaches to bruxism assessment and management in clinical settings, suggesting gaps in practitioner knowledge evidenced by the varied responses.

ABBREVIATIONS

PBRN - Practice-Based Research NetworkMMA - Masticatory muscle activitySB - Sleep bruxismAB - Awake bruxismTMJ - Temporomandibular jointOSA - Obstructive sleep apnea.

Temporomandibular Disorders Within the Context of Sleep Disorders

This paper provided an overview of the knowledge on the relationship between temporomandibular disorders (TMDs) and the main sleep conditions and disorders of dental interest, namely, sleep bruxism (SB), sleep apnea, and gastroesophageal reflux disease (GERD). It emerged that although the topic of SB as a possible detrimental factor for the stomatognathic structures has been the most studied, evidence is growing that SB, obstructive sleep apnea, and GERD, all belong to a circle of mutually interacting sleep disorders and conditions that, in turn, may be associated with TMDs. The pathophysiology of the cause-and-effect relationships, if existing, has to be elucidated yet.

Effectiveness of Biofeedback in Individuals with Awake Bruxism Compared to Other Types of Treatment: A Systematic Review

Excessive masticatory muscle activity is generally present in awake bruxism, which is related to increased anxiety and stress. It has been hypothesized that biofeedback could potentially manage awake bruxism, however, its effectiveness has not been empirically analyzed in a systematic manner. Therefore, this systematic review was designed to determine the effectiveness of biofeedback compared to other therapies in adults with awake bruxism. Extensive searches in five databases looking for randomized controlled trials (RCTs) that included biofeedback to manage awake bruxism were targeted. The risk of bias (RoB) assessment was conducted using the Cochrane RoB-2 tool. Overall, four studies were included in this systematic review, all of which used the electromyographic activity of the masticatory muscles during the day and night as the main endpoint. Auditory and visual biofeedback could reduce the excessive level of masticatory muscle activity in a few days of intervention. The majority of the included studies had a high RoB and only one study had a low RoB. The standardization of the biofeedback protocols was also inconsistent, which makes it difficult to establish the ideal protocol for the use of biofeedback in awake bruxism. Thus, it is proposed that future studies seek to reduce methodological risks and obtain more robust samples.

Electromyographic Assessment of Masseter Muscle Activity: A Proposal for a 24 h Recording Device with Preliminary Data

OBJECTIVE

The instrumental measurement of electromyographic (EMG) activity in the natural environment is the best strategy available to collect information on bruxism. The twofold aim of this study was to (1) introduce and discuss a novel EMG device for the assessment of awake (AB) and sleep bruxism (SB) in the home environment over 24 h and (2) present some preliminary data.

METHODS

Fifteen healthy volunteers (eight males and seven females; mean age: 48.2 ± 4.1 years) underwent 24 h EMG recording trials of their masseter muscle activity (MMA) with a miniaturized wireless device. This device allowed us to measure the durations of the different phases of the recordings (total duration, awake time, sleep time, and electrode dislodgement time) as well as the bruxism time index (BTI) and bruxism work index (BWI) for both the waking and sleeping hours.

RESULTS

For the healthy volunteers, on average, the bruxism work index (BWI) values were 0.4 ± 0.2 and 0.1 ± 0.1 for awake and sleep, respectively, while the mean bruxism time index (BTI) values were 0.9 ± 0.5 for awake and 0.3 ± 0.1 for sleep.

CONCLUSIONS

This investigation describes the technical features of a novel EMG recording device that permits the evaluation of masseter muscle activity in the home environment over 24 h. For the first time, a dedicated elaboration of the EMG signal allowed an assessment of muscle work and not just a count of purported SB/EMG events.

CLINICAL SIGNIFICANCE

Based on the multidisciplinary approach in the study of bruxism, such a methodology, thanks to its peculiar features, will allow researchers and clinicians to monitor the epidemiology of MMA and delve deeper into the awake and sleep bruxism correlates for tailored management in clinical settings.

Impact of bruxism on craniomandibular morphology: A cone-beam computed tomographic study

OBJECTIVE

The main goal of this work was to address craniomorphological characteristics of patients with bruxism when compared to those without bruxism using cone beam computed tomography (CBCT) imaging.

METHODS

Seventy CBCT images of an equal number (n = 35) of orthodontic patients with and without bruxism (age range, 18-44 years) were retrospectively analyzed. Sagittal evaluation, mandibular shape, and skeletal asymmetry were systematically assessed in both groups.

RESULTS

Significant differences (p < 0.05) were observed between groups for Right Articular Fossa (AF) - Axial Plane (AP) and Left AF - AP (B > NB), Right Gonial Angle (GA), Left GA, Sella-Nasion and Occlusal Plane (B < NB). Age (13%), Condyle-Gonion (18%), AF to AP (67%), and Mental-AP (16%) had the greatest impact on bruxers.

CONCLUSION

In this study, the CBCT 3D image showed significant differences in craniofacial morphology, particularly in the mandibular structure of bruxers compared with non-bruxers.

Prevalence of temporomandibular disorders and its association with malocclusion in children: A transversal study

This study investigated the prevalence of temporomandibular disorders (TMDs) in a sample of children and adolescents and evaluated the correlation with occlusal variables. TMD signs and symptoms were recorded in 411 subjects (age range 7-15 years), divided into two groups: 214 subjects treated in Chieti (Italy) CG group and 197 in Murcia (Spain) MG group. Once the Angle dental class was identified, it was recorded if there were signs and symptoms of temporomandibular disorders (TMDs) and occlusal interferences. The percentages of signs and symptoms were compared to determine the differences among the groups for TMDs, bruxism, joint sounds, deviation during the opening, reduced opening/lateral/protrusive movements, malocclusions, and myofascial pain. There is no statistically significant difference between the two groups (χ² = 1.057, p > 0.05). Subjects with Angle Class I (37.37%), deep bite (43.43%), and increased overjet (41.41%) showed a higher prevalence of TMD symptoms.

Current Knowledge and Future Perspectives on Awake Bruxism Assessment: Expert Consensus Recommendations

Awake bruxism (AB) is differentiated from sleep bruxism (SB) by the differences in etiology, comorbidities, and consequences related to the different spectrum of muscle activities exerted in relation to the different circadian manifestations. Furthermore, less literature data are available on AB than on SB. The introduction of ecological momentary assessment (EMA) strategies has allowed for collecting valuable data on the frequency of the different activities reported by an individual in his/her natural environment. This strategy has been further improved with the recent use of smartphone technologies. Recent studies have described an average frequency of AB behaviors, within the range of 23-40% for otherwise healthy young adults. An association between AB and some psychological traits has emerged, and the findings have indicated that patients with musculoskeletal symptoms (e.g., temporomandibular joint and/or muscle pain, muscle stiffness, and fatigue) report higher AB frequencies. Preliminary data suggest that muscle bracing and teeth contact are the most commonly reported behaviors, while teeth clenching is much less frequently reported than commonly believed previously. Report of teeth grinding during wakefulness is almost absent. This paper has critically reviewed the currently available approaches for the assessment of AB. In addition, some future perspectives and suggestions for further research have been provided.

Incidence of Sleep Bruxism in Different Phenotypes of Obstructive Sleep Apnea

(1) Background: Sleep bruxism (SB) is a common sleep behavior. Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder with potential long-term major neurocognitive and cardiovascular sequelae. Although the co-occurrence of SB and OSA has been described previously, the exact relationship remains unclear. The present study aimed to evaluate the incidence of SB in different phenotypes of OSA. (2) Methods: The participants of this study were adult patients referred to the Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology at the Wroclaw Medical University. They underwent a single-night video polysomnography in a sleep laboratory. The data related to common OSA phenotypes were analyzed in two separate groups of patients: body position related (n = 94) and rapid eye movement (REM) related (n = 85). (3) Results: The obtained results showed that the incidence of SB and severe SB was higher for body position-related OSA phenotype (p < 0.05 for all comparisons). No statistically significant differences were observed for REM-related OSA phenotype (p > 0.05 for all comparisons). (4) Conclusions: Body position-related OSA phenotype seems to be associated with higher SB and severe SB incidence, but the relationship is not independent. However, in the light of the unclear relationship between SB and sleep-disordered breathing, the topic needs further study.

The Influence of Steroid Hormones on Tooth Wear in Children and in Adolescents

(1) Background: From a young age, boys are more often affected by tooth wear than girls. This suggests an influence of the male sex hormone (testosterone) on the aetiology of tooth wear. The aim of the present study was to investigate the incidence of tooth wear in relation to steroid hormone levels in children. (2) Methods: 1022 test persons aged between 10 and 18 (491 male, 531 female) from the LIFE Child study underwent medical and dental examination. Tooth wear was measured through clinical inspection. Blood samples were taken to determine hormone levels (testosterone, SHBG). The level of free testosterone was calculated from the ratio of testosterone to SHBG. Using multivariable methods, the incidence of tooth wear was analyzed as a function of hormone levels, while controlling for confounders such as age, sex, social status, and orthodontic treatment. (3) Results: The incidence of tooth wear increased with age in both sexes. Boys showed significantly more often attrition facets than girls (17.5% vs. 13.2%, p < 0.001). Subjects with tooth wear showed significantly higher free testosterone levels than those without (males: p < 0.001, females: p < 0.05). After controlling for confounding variables, the risk of tooth wear increased by approximately 30.0% with each year of life (odds ratio [OR]boys = 1.29, 95% confidence interval [CI] = 1.04−1.56; [OR]girls = 1.32, 95% CI = 1.08−1.61). In addition, the risk of tooth wear increased by 6.0% per free testosterone scale score only in boys (OR = 1.06, 95% CI = 1.01−1.12). (4) Conclusions: Tooth wear is common in children and in adolescents, and it increases steadily with age in both sexes. The stronger increase and the higher prevalence among male adolescents can be explained by the additional effect of free testosterone.

Temporomandibular Disorders and Bruxism in Patients Attending a Tinnitus Clinic

The current study investigated the coexistence of temporomandibular disorder (TMD) and/or bruxism among 51 individuals seeking treatment in a tinnitus clinic. All participants completed a Hebrew version of the Tinnitus Handicap Inventory (THI), depression and anxiety questionnaires, and the diagnostic criteria TMD (DC/TMD) questionnaire. In addition to questionnaires, the participants underwent a clinical evaluation of the oral cavity, facial muscles, and the temporomandibular joint (TMJ). Thirty-four participants (66.7%) were diagnosed with bruxism, while TMD was found in 14 (27.5%) of the cases. Patients with both tinnitus, TMD and bruxism scored the highest in the anxiety questionnaire. The severity of depression was found to be significantly associated with the tinnitus severity. These results emphasize the clinical bond between tinnitus, TMD, and bruxism.

Oral appliances reduce masticatory muscle activity-sleep bruxism metrics independently of changes in heart rate variability

OBJECTIVES

Sleep bruxism (SB) is associated with physiological activities including sympathetic autonomic system dominance and sleep micro-arousal. While oral appliances (OA) are used to prevent SB harmful effects, the influence of OAs physiological mechanisms during sleep is unknown. The aim of this study is to assess whether heart rate variability (HRV) changes, as a marker of autonomic nervous system activity, would be associated with the OA mechanism of action on SB using occlusal splint (OS) and mandibular advancement splint (MAS).

MATERIALS AND METHODS

A retrospective analysis, from data previously collected in 21 participants with SB (25.6 ± 4.5 years) with polysomnographic recordings, was done. HRV data were compared between a reference night (no-device) and ones during which OS or MAS was used in a crossover study design. Rhythmic masticatory muscle activity (RMMA) index was compared between nights. HRV was evaluated using autoregressive model analysis for three sections: baseline (distance from RMMA), immediately before, and after RMMA period.

RESULTS

A significant reduction in RMMA index, when wearing OA during sleep, was observed (P < 0.01), but was not associated with HRV parameters change. HRV significantly changed after RMMA onset for nights with OA during non-REM sleep in comparison with baseline (P < 0.02).

CONCLUSIONS

The usage of OAs for SB participants reduced RMMA, but most likely independently of changes in HRV linked to the mechanism associated with SB genesis.

CLINICAL RELEVANCE

Wearing OA seems to reduce grinding noise and protect from dental injuries but does not seem to influence SB genesis.

Associations between Bruxism, Stress, and Manifestations of Temporomandibular Disorder in Young Students

Bruxism is a repetitive activity of the masticatory muscles, which determine teeth grinding or clenching, associated with rigidity, bracing, or thrusting of the mandibula. The aim of this study was to determine the prevalence of possible bruxism in 328 students attending the Faculty of Dental Medicine, University of Medicine and Pharmacy of Craiova, and its associations with stress and other manifestations of the temporo-mandibular disorder. This was a questionnaire-based study to collect information on self-evaluation of bruxism presence, frequency of specific episodes, stress, anxiety, and other manifestations of temporo-mandibular disorder. Self-evaluated bruxism was identified in 39.33% from the entire study group, allowing us to define two subgroups for further analysis. Sleep bruxism was present in 16.28% of participants; awake bruxism was present in 68.99%, while 14.73% of participants presented a combined form. The main manifestation of bruxism was reported as teeth grinding. Fatigue was identified as a common clinical sign of bruxism and temporo-mandibular disorder. Group distribution analysis (Chi-Square) indicated significant associations between bruxism and stress, panic, restlessness, or increased stress during the COVID-19 pandemic (p < 0.05). Bruxism, and especially awake bruxism, has increased in prevalence among young students, and it has been associated with increased levels of stress.

Monitoring of awake bruxism by intelligent app

Background. Bruxism is a topic of much controversy and is continually debated in the field of dentistry due to the multifaceted clinical relationship that results in painful conditions and consequences to patients. The aim of this review was to determine the effectiveness of a smartphones app in monitoring awake bruxism. Methods. PROSPERO (registration number: CRD42021271190). The eligibility criteria were as followed: observational studies, case-control studies, studies that reported odds ratios, and studies on awake bruxism. The following keywords were searched: [smartphones apps] AND [apps] AND [awake bruxism], OR [sleep bruxism], OR [sleep hygiene], OR [parasomnias], AND [habits]. Results. All the included studies found that the use of the smartphone app allows controlled awake bruxism monitoring. The results also show that the slepp bruxism and awake bruxism  are interactive, having negative synergism and substantially increasing the risks of temporomandibular joint pain and temporomandibular disorders. Discussion. In the awake bruxims it was possible to identify 70% symptoms through the different frequencies of behavior provided by the App, within the present technological tools have become daily in young and adult population. The app is effective and easy to use by patients, effectively limiting biases the time of evaluation.

Monitoring of awake bruxism by intelligent app

Background. Bruxism is a topic of much controversy and is continually debated in the field of dentistry due to the multifaceted clinical relationship that results in painful conditions and consequences to patients. The aim of this review was to determine the effectiveness of a smartphones app in monitoring awake bruxism. Methods. PROSPERO (registration number: CRD42021271190). The eligibility criteria were as followed: observational studies, case-control   studies, studies that reported odds ratios, and studies on awake bruxism. The following keywords were searched: [smartphones apps] AND [apps] AND [awake bruxism], OR [sleep bruxism], OR [sleep hygiene], OR [parasomnias], AND [habits]. Results. All the authors agree that the use of the smartphone app allows controlled awake bruxism monitoring. The results also show that                                     the two bruxism are interactive, having negative synergism and substantially increasing the risks of temporomandibular joint pain and temporomandibular disorders. Discussion. In the AB it was possible to identify 70% symptoms through the different frequencies of behavior provided by the App, within the present technological tools have become daily in young and adult population. The app is effective and easy to use by patients, effectively limiting biases the time of evaluation.

Parkinson's disease, temporomandibular disorder pain and bruxism and its clinical consequences: a protocol of a single-centre observational outpatient study

INTRODUCTION

A recent questionnaire-based study suggested that bruxism and painful temporomandibular disorders (TMD pain) may be more prevalent in patients with Parkinson's disease (PD) compared with controls. The presence of both bruxism and TMD pain may negatively influence patients' quality of life. The present study is designed to clinically and more objectively investigate the presence of bruxism and TMD pain in patients with PD. The secondary aim of the study is to identify factors associated with bruxism and TMD pain in patients with PD, such as disease severity and dopaminergic medication usage. Furthermore, the presence of tooth wear in patients with PD will be studied as this can be a major consequence of bruxism. Finally, deviations in saliva composition that may contribute to tooth wear will be studied.

METHODS AND ANALYSIS

This is a single-centre observational outpatient study at the Amsterdam University Medical Centres, location VUmc. All patients with a clinical diagnosis of PD will be eligible for inclusion. Participants will fill in a set of questionnaires. Subsequently, patients will be examined clinically for, among others, TMD pain, presence and severity of tooth wear, and deviations in saliva composition. Sleep-time registrations will take place for 5 nights with the GrindCare GC4 (ie, a portable, single-channel electromyographic recorder) to assess sleep bruxism and simultaneously by the use of the BruxApp for 5 days to assess awake bruxism. We will partly use data collected during standard clinical care to minimise patient burden.

ETHICS AND DISSEMINATION

The scientific and ethical aspects of this study protocol have been approved by the Medical Ethics Review Committee of the Amsterdam UMC, location VUmc; NL. 2019.143. Informed consent will be obtained from all participants. The results will be published in a peer-reviewed journal, if relevant presented at conferences, and published as part of a PhD thesis.

TRIAL REGISTRATION NUMBER

NL8307.

Accuracy of Surface Electromyography in the Diagnosis of Pain-Related Temporomandibular Disorders in Children with Awake Bruxism

The study assessed masticatory muscle electromyographic (EMG) activity in both children diagnosed with pain-related temporomandibular disorders (TMD-P) and awake bruxism (AB) and in children without TMD, as well as the diagnostic value of surface electromyography (sEMG) in diagnosing TMD-P in subjects with AB. After evaluation based on the Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), 30 children diagnosed with myofascial pain were included in the myofascial pain group and 30 children without TMD diagnosis comprised the control group (mean age of 9.49 ± 1.34 years). The activity of the anterior temporal (TA) and masseter (MM) muscle was assessed bilaterally using a DAB-Bluetooth device (zebris Medical GmBH, Germany) at rest and during maximum voluntary clenching (MVC). The receiver operating characteristic (ROC) curve was used to determine the accuracy, sensitivity, and specificity of the normalized sEMG data. Statistically significant intergroup differences were observed in TA and MM muscle EMG activity at rest and during MVC. Moderate degree of sEMG accuracy in discriminating between TMD-P and non-TMD children was observed for TAmean, left MM, and MMmean EMG muscle activity at rest. sEMG can be a useful tool in assessing myofascial TMD pain in patients with AB.

Polymorphic variants in genes related to stress coping are associated with the awake bruxism

BACKGROUND

Chronic stress is one of the leading predisposing factors in bruxism aetiology, but the influence of genetic factors is also suggested. We aimed to study whether sequence variants in genes involved in stress regulation pathways: NTRK2 and BDNF, may be associated with awake bruxism susceptibility, clinical presentation, and patients' perceived stress level.

METHODS

The study group included 104 patients with probable awake bruxism and 191 population controls. Patients underwent dental examination concerning the symptoms of bruxism and psychological testing. Genotyping was performed using HRMA and sequencing. Statistical analyses were conducted, and P values below 0.05 were considered statistically significant.

RESULTS

We observed a positive correlation of measured stress level and pathological teeth attrition in the anterior segment (r = 0.45, P < 0.001), enamel attritions (r = 0.44, P < 0.001), tongue impressions (r = 0.50, P < 0.001) and posterior teeth attrition (r = 0.27, P = 0.005). Moreover, the c.196A variant (p.66Met) of the BDNF gene and c.1397-31392G allele of the NTRK2 gene were present with elevated frequency, comparing to controls.

CONCLUSIONS

This study hence the thesis that perceived stress level is a substantial contributing factor to awake bruxism occurrence and its clinical manifestations. Moreover, sequence variants in genes related to stress coping may be correlated with awake bruxism's susceptibility via elevated perceived stress level.

Temporomandibular disorders in patients with polysomnographic diagnosis of sleep bruxism: a case-control study

BACKGROUND

Temporomandibular disorders (TMD) is a collective term that refers to complaints of temporomandibular joint (TMJ) pain, fatigue and/or pain of the craniocervical muscles, limitation of movement of the mandible, and TMJ noises. Sleep bruxism (SB) is a disorder involving rhythmic (phasic) or non-rhythmic (tonic) masticatory muscle activity during sleep and is not a movement disorder or a sleep disorder in otherwise healthy individuals. The present study aimed to support or reject the null hypothesis that there is no association between SB and TMD.

METHODS

The study population was recruited from patients who visited the Artmedica Clinic, Mossoro city, Rio Grande do Norte, Brazil. Patients who underwent polysomnography received information about the research and were invited to participate following the inclusion and exclusion criteria. The study sample consisted of 40 individuals with age ranging from 19 to 76 years. The subjects were administered the questionnaire of the European Academy of Craniomandibular Disorders (AEDC). Those who answered affirmatively to at least one question of the questionnaire were recommended to visit the primary researcher's dental clinic for examination; those who met the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were evaluated, and their condition was classified into one or more subtypes of TMD. The subjects were divided into 4 groups according to the polysomnographic findings and the responses to the AEDC questionnaire. Of the 40 individuals who answered the AEDC questionnaire and underwent polysomnography, 28 presented with TMD symptoms. The data were expressed as simple frequency and percentage values using statistical software. Values of p < 0.05 were considered to be significant.

RESULTS

The results showed that the frequency of TMD in individuals diagnosed to have SB was 46.4%. According to the DC/TMD of the 28 individuals, the most prevalent TMD subtype was local myalgia (85.7%). Of the total subjects, 32.5% had TMD and SB, 36.4% were males, and in the age range of 31 to 40 years (40%).

CONCLUSION

In this study sample, there was no association between SB as currently defined and TMD, thus confirming previous findings on this topic.

[Prevalence of temporomandibular disorders in seniors-Symptom-related analyses in younger and older seniors]

Hintergrund

Kraniomandibuläre Dysfunktionen (CMD) können auch im hohen Alter auftreten. Die Prävalenz von CMD-Symptomen bei Senioren wurde bisher nur wenig untersucht.

Ziel der Arbeit

Ziel dieser Untersuchung war es, die Prävalenz von Symptomen einer CMD bei Senioren nach Befunderhebung mit den Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) zu bestimmen. Dabei sollten die Prävalenzwerte von jüngeren (60 bis 74 Jahren) und älteren (≥ 75 Jahre) Senioren verglichen werden.

Material und Methoden

Im Rahmen der Interdisziplinären Längsschnittstudie des Erwachsenenalters (ILSE) wurden Probanden nach repräsentativen Gesichtspunkten rekrutiert. Während der vierten Nachverfolgungswelle im Zeitraum von 2014 bis 2016 im Bereich des Studienzentrums Leipzig wurden die Probanden auf das Vorliegen von anamnestischen und klinischen CMD-Symptomen untersucht.

Ergebnisse

Anamnestische CMD-Symptome bei Senioren (n = 192) waren v. a. durch Schmerzen im Gesichtsbereich (13,0 %) gekennzeichnet. Das häufigste klinische CMD-Symptom waren Kiefergelenkgeräusche mit einer Prävalenz bis zu 35,5 %. Frauen gaben anamnestisch häufiger Kopfschmerzen/Migräne an. Kiefergelenkgeräusche und eine limitierte Mundöffnung wurden klinisch häufiger bei weiblichen Teilnehmenden beobachtet. Statistisch signifikante Unterschiede zeigten sich bei dem Vergleich von jüngeren und älteren Senioren hinsichtlich der Prävalenz von Kopfschmerzen/Migräne, jedoch nicht bei klinischen Symptomen.

Schlussfolgerung

Anamnestisch werden Gesichtsschmerzen von 13,0 % der Senioren angegeben. Kiefergelenkgeräusche werden bei jedem dritten Älteren klinisch beobachtet. CMD-Symptome scheinen bei jüngeren und älteren Senioren im ähnlichen Maße ausgeprägt zu sein.

Signal acquisition and analysis of ambulatory electromyographic recordings for the assessment of sleep bruxism: A scoping review

BACKGROUND

Ambulatory electromyographic (EMG) devices are increasingly being used in sleep bruxism studies. EMG signal acquisition, analysis and scoring methods vary between studies. This may impact comparability of studies and the assessment of sleep bruxism in patients.

OBJECTIVES

(a) To provide an overview of EMG signal acquisition and analysis methods of recordings from limited-channel ambulatory EMG devices for the assessment of sleep bruxism; and (b) to provide an overview of outcome measures used in sleep bruxism literature utilising such devices.

METHOD

A scoping review of the literature was performed. Online databases PubMed and Semantics Scholar were searched for studies published in English until 7 October 2020. Data on five categories were extracted: recording hardware, recording logistics, signal acquisition, signal analysis and sleep bruxism outcomes.

RESULTS

Seventy-eight studies were included, published between 1977 and 2020. Recording hardware was generally well described. Reports of participant instructions in device handling and of dealing with failed recordings were often lacking. Basic elements of signal acquisition, for example amplifications factors, impedance and bandpass settings, and signal analysis, for example rectification, signal processing and additional filtering, were underreported. Extensive variability was found for thresholds used to characterise sleep bruxism events. Sleep bruxism outcomes varied, but typically represented frequency, duration and/or intensity of masticatory muscle activity (MMA).

CONCLUSION

Adequate and standardised reporting of recording procedures is highly recommended. In future studies utilising ambulatory EMG devices, the focus may need to shift from the concept of scoring sleep bruxism events to that of scoring the whole spectrum of MMA.

Identifying predictive factors for sleep bruxism severity using clinical and polysomnographic parameters: a principal component analysis

STUDY OBJECTIVES

The aim was to identify predictive factors for sleep bruxism (SB) severity among polysomnographic parameters, salivary cortisol levels, temporomandibular disorders, age, and sex.

METHODS

Young adults (19-30 years) were screened for self-/roommate reports of teeth grinding/clenching during sleep associated with clinical signs of tooth wear. Individuals positive for both conditions were administered a polysomnographic exam to provide a definite diagnosis of SB (n = 28). Healthy participants without SB signs/symptoms were also included (n = 15). The Research Diagnostic Criteria for Temporomandibular Disorders was applied to determine functional, muscular, and articular domains of the Temporomandibular Index. Cortisol awakening levels were measured in saliva. Principal component analysis was used to extract the latent components emerging from polysomnographic results, and 2 regression models were adjusted to predict the number and duration of bruxism episodes.

RESULTS

Principal component analysis resulted in 4 components-C1: %N1, total sleep time, sleep efficiency, arousals/microarousals; C2: %N2, %N3; C3: periodic limb movements and apneas; C4: %REM and REM latency. The number of SB episodes/h was predicted by increasing muscular scores and C2 (decrease in %N2 and increase in %N3) (adjusted R² = 45%; P =.001). The total time of SB episodes was predicted by decreased articular and increased functional scores, age, and female sex (adjusted R² = 36%; P = 0.010). Salivary cortisol levels were not associated with SB severity and did not differ between groups.

CONCLUSIONS

The findings showed that SB severity was predicted by muscular and functional scores, female sex, and distinct polysomnographic patterns, contributing to the deeper knowledge of the underlying pathophysiology of SB severity; additionally, the findings can help to formulate health approaches that are specific to the patient and will better assist in treating this condition.

Sleep Bruxism: An Integrated Clinical View

The vision of adult sleep bruxism (SB) has changed over time. Thus, among the most important concomitant factors of SB noted are the pathophysiological aspect, namely sleep arousal, obstructive sleep apnea, gastroesophageal pH/gastroesophageal reflux disease, and the use or abuse of certain substances. The aim of this article was to review the main clinically relevant pathophysiological SB-associated factors and a proposal for a diagnostic process.

[Prevalence of temporomandibular disorders according to the simplified fonseca anamnestic index in dentistry students of the juárez university of the state of durango, mexico]

Objective

The objective was to estimate the prevalence of temporomandibular disorders (TMD), in students of the Faculty of Dentistry.

Material and Methods

This was a descriptive, observational, prospective, cross-sectional study. The study included 18 to 28-year-old students from the Faculty of Dentistry of the Universidad Juárez del Estado de Durango, México, attending the 1st to 8th semester of the 2018-A school year in whom the simplified Fonseca anamnestic index (sFAI) was applied to characterize TMD. The sample size was determined using the Epi InfoTM software, obtaining a total sample size of 263 individuals. The R Studio (2019) statistical package was used to describe the data.

Results

The prevalence of TMD in the study population was 63%, with a mild disorder being the most prevalent in 44%. The Chi2 test showed statistically significant differences between sex and TMD (p = 0.001) and between sex and 5 items of the sFAI: item 4 (p= 0.001), item 7 (p= 0.001), item 8 (p = 0.021), item 9 (p= 0.001) and item 10 (p = 0.001).

Conclusions

There is a high prevalence of TMD in the student population of the Faculty of Dentistry of the Universidad Juárez del Estado de Durango, Mexico, with females presenting a higher prevalence of the presence and manifestation of symptoms in these disorders.

Prevalence of clinical signs and symptoms of the masticatory system and their associations in children with sleep bruxism: A systematic review and meta-analysis

Sleep bruxism (SB) is a behavior of central origin that is related to different factors. This systematic review aimed to determine the prevalence of clinical signs and symptoms of the masticatory system and their association in children with SB. A structured search in ten databases were taken. Two authors independently selected studies, extracted the data, study quality assessment and graded the evidence. A meta-analysis of proportion and association was performed under random-effect model, confidence interval of 95% and p < 0.05 for pulled values. Were included 22 studies, and their overall quality was poor. The more common clinical signs and symptoms of the masticatory system in children with SB were primary canine wear (P:84.13, 95% CI:78.13-89.32; p = 0.248; I² 25.05), dental wear (P:73.76, 95% CI:38.73-96.91; p < 0.001; I² 97.62) and headache (P:52.85, 95% CI:38.92-66.56; p < 0.001; I² 93.65). The prevalence of SB in children was 31.16% (P:31.16, 95% CI:22.18-40.92; p < 0.001; I² 98.56). There was no significant risk of dental wear and headache in children with SB. There is low to very low certainty of the evidence. The more prevalent clinical signs and symptoms of the masticatory system presented in children with SB were primary canine wear, dental wear and headache. Further studies of high quality are still needed to elucidate these important questions.

Research routes on improved sleep bruxism metrics: Toward a standardised approach

A recent report from the European Sleep Research Society's task force "Beyond AHI" discussed an issue that has been a long-term subject of debate - what are the best metrics for obstructive sleep apnoea (OSA) diagnosis and treatment outcome assessments? In a similar way, sleep bruxism (SB) metrics have also been a recurrent issue for >30 years and there is still uncertainty in dentistry regarding their optimisation and clinical relevance. SB can occur alone or with comorbidities such as OSA, gastroesophageal reflux disorder, insomnia, headache, orofacial pain, periodic limb movement, rapid eye movement behaviour disorder, and sleep epilepsy. Classically, the diagnosis of SB is based on the patient's dental and medical history and clinical manifestations; electromyography is used in research and for complex cases. The emergence of new technologies, such as sensors and artificial intelligence, has opened new opportunities. The main objective of the present review is to stimulate the creation of a collaborative taskforce on SB metrics. Several examples are available in sleep medicine. The development of more homogenised metrics could improve the accuracy and refinement of SB assessment, while moving forward toward a personalised approach. It is time to develop SB metrics that are relevant to clinical outcomes and benefit patients who suffer from one or more possible negative consequences of SB.