Sleep bruxism in individuals with and without attrition-type tooth wear: An exploratory matched case-control electromyographic study

Tooth wear and bruxism: A scoping review

OBJECTIVE

This study presents a scoping review to determine the association between tooth wear and bruxism.

DATA

A protocol was developed a priori (Open Science Framework (DOI 10.17605/OSF.IO/CS7JX)). Established scoping review methods were used for screening, data extraction, and synthesis. Risk of bias was assessed using JBI tools. Direct associations between tooth wear and bruxism were assessed.

SOURCES

Embase, SCOPUS, Web of Science, Cochrane, and PubMed were searched.

STUDY SELECTION

Any clinical study containing tooth wear and bruxism assessment done on humans in any language was included. Animal, in-vitro studies and case reports were excluded.

CONCLUSIONS

Thirty publications reporting on the association between tooth wear and bruxism were included. The majority of publications were cross-sectional studies (90%) while only three were longitudinal (10%). Eleven papers assessed definitive bruxism for analysis (instrumental tools), one paper assessed probable bruxism (clinical inspection with self-report) and eighteen assessed possible bruxism (self-report). Of the eleven papers assessing definitive bruxism, eight also reported outcomes of non-instrumental tools. Tooth wear was mostly scored using indexes. Most studies reported no or weak associations between tooth wear and bruxism, except for the studies done on cervical tooth wear. When bruxism assessment was done through self-report, more often an association was found. Studies using multivariate analyses did not find an association between tooth wear and bruxism, except the cervical wear studies. Evidence shows inconclusive results as to whether bruxism and tooth wear are related or not. Therefore, well-designed longitudinal trials are needed to address this gap in the literature.

CLINICAL SIGNIFICANCE

Based on the evidence, dental clinicians should not infer bruxism activity solely on the presence of tooth wear.

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.

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.

Risk factors of tooth wear in permanent dentition: A scoping review

BACKGROUND

Tooth wear (TW) prevalence is high and increasing and has important consequences on the patient's quality of life. Knowledge of risk factors is crucial to promote diagnosis, prevention strategies and timely interceptive treatment. Many studies have identified TW risk factors.

OBJECTIVE

This scoping review aims to map and describe suspected available factors associated with TW in permanent dentition based on quantitative measurement.

METHODS

The scoping review was conducted using the PRISMA extension of the Scoping Reviews checklist. The search was conducted in October 2022 from the Medline® (PubMed® interface) and Scopus® databases. Two independent reviewers selected and characterised the studies.

RESULTS

2702 articles were identified for assessment of titles and abstracts, and 273 articles were included in the review. The results show a need to standardise TW measurement indices and the study design. The included studies highlighted various factors, classified into nine domains: sociodemographic factors, medical history, drinking habits, eating habits, oral hygiene habits, dental factors, bruxism and temporomandibular disorders, behavioural factors, and stress. Results related to chemical TW (erosion) risk factors underline the importance of eating disorders, gastroesophageal reflux and lifestyle, particularly drinking and eating behaviours, which supports developing public health information campaigns and interventions. Besides chemical, this review identifies evidence of several mechanical TW risk factors, such as toothbrushing and bruxism; the influence of this last factor needs to be further explored.

CONCLUSIONS

TW management and prevention require a multidisciplinary approach. Dentists are in the first line to detect associated diseases such as reflux or eating disorders. Consequently, practitioners' information and guideline diffusion should be promoted, and a TW risk factors checklist (the ToWeR checklist) is proposed to help diagnostic approaches.

Frequency distribution of the number and amplitude of electromyographic waveforms of the masseter muscle during sleep in patients with a clinical diagnosis of sleep bruxism

OBJECTIVE

This study aimed to clarify frequency distribution of number and peak amplitude of electromyographic (EMG) waveforms of sleep bruxism (SB) in outpatients with clinical diagnosis of SB (probable bruxer: P-bruxer).

METHODS

Subjects were 40 P-bruxers. Masseteric EMG during sleep was measured at home using a wearable EMG system. EMG waveforms with amplitude of more than two times the baseline and with duration of 0.25 s were extracted as SB bursts. Clusters of bursts, i.e. SB episodes, were also scored.

RESULTS

There were large variations among the subjects in numbers of SB bursts and episodes and in burst peak amplitude. As for burst peak amplitude within a subject, a wide right-tailed frequency distribution was shown with the highest frequency at the class of 5-10% maximum voluntary contraction.

CONCLUSION

The number and amplitude of SB waveforms for P-bruxers were distributed over a wide range, indicating the existence of large individual differences.

Awake and Sleep Bruxism Prevalence and Their Associated Psychological Factors in First-Year University Students: A Pre-Mid-Post COVID-19 Pandemic Comparison

There is a broad consensus accepting that psychological variables such as stress, anxiety, or depression play an important role in bruxism. The COVID-19 pandemic has led to an increase in stress, anxiety, and depression levels. The purpose of this study was to evaluate the impact of the COVID-19 pandemic on possible awake and sleep bruxism prevalence and on the psychological factors associated with bruxism, comparing pre-pandemic, pandemic/lockdown, and post-pandemic samples of first-year students. A total of 274 dentistry students from the Complutense University of Madrid participated in the study: 92 from 2018/2019 (pre-pandemic), 90 from 2020/2021 (pandemic), and 92 students from 2021/2022 (post-pandemic) academic years. The participants filled out a thorough battery of validated questionnaires evaluating bruxism and different psychological characteristics, such as anxiety, depression, somatization, personality, and stress coping styles. While sleep bruxism prevalence was significantly higher for the pandemic group, awake bruxism was smaller in comparison to pre-pandemic and post-pandemic groups. The post-pandemic group also presented higher levels of neuroticism and agreeableness personality traits, and positive reappraisal than the pre-pandemic group, with the pandemic group somewhere in between. Additionally, both the pandemic and post-pandemic group showed higher levels of depression and acceptance/resignation coping styles than the pre-pandemic group. Thus, among the three groups of students, the post-pandemic group was the one that showed a larger effect of the pandemic situation in their psychological variables, presenting higher levels of anxiety (state and trait), depression, acceptation/resignation coping style, higher neuroticism (emotional instability trait), and lower agreeableness trait. Nonetheless, the increase of positive reappraisal in the post-pandemic group (an adaptive coping stress style) might be also a sign of recovery. The higher sleep bruxism for the pandemic group might be related to the pandemic situation and lockdown, passively suffered, possibly promoting feelings of impotency, increased levels of depression and acceptance/resignation (normally considered a passive/maladaptive coping style), while acute stressful situations derived from daily personal social interactions might have increased anxiety levels and induced higher levels of awake bruxism observed in both the pre-pandemic and post-pandemic groups. However, further research, including larger and more representative samples, is needed to confirm this possible relationship.

Portable and wearable electromyographic devices for the assessment of sleep bruxism and awake bruxism: A literature review

OBJECTIVE

The current state of portable/wearable electromyographic (EMG) devices for assessment of bruxism was reviewed.

METHODS

A search of full-text articles relevant to portable/wearable EMG devices capable of being used at home was performed. The data source used was MEDLINE via PubMed from January 1970 to July 2019.

RESULTS

There were nine kinds of wearable EMG devices capable of being used under unrestrained conditions. Ultra-miniaturized wearable EMG devices with a level of performance equivalent to that of conventional stationary EMG devices have been developed and are being used during sleep and in the daytime. The devices have a high level of diagnostic accuracy for sleep bruxism. A definite cut-off value for awake bruxism has not been established.

DISCUSSION

Assessment of sleep bruxism with a high level of accuracy can be performed using a portable/wearable EMG device. However, a definite cut-off value is required for assessment of awake bruxism.

Validity of clinical diagnostic criteria for sleep bruxism by comparison with a reference standard using masseteric electromyogram obtained with an ultraminiature electromyographic device

Evaluation of sleep bruxism (SB) in clinical practice is currently conducted based on clinical findings, i.e., clinical diagnostic criteria consisting of medical interview, findings of tooth wear, and symptoms of temporomandibular joint (TMJ) and muscles. However, there are many unclear points about validity of the criteria. In this study, validity tests were conducted to clarify the accuracy of the clinical diagnostic criteria for SB by comparison with a reference standard using a single-channel masseteric electromyogram (EMG) obtained with ultraminiature electromyographic devices. The subjects included 30 'probable' bruxers (P-bruxers) who were clinically diagnosed as having SB and 30 non-bruxers. EMG was recorded during sleep under unrestrained and accustomed condition at each subject's home using ultraminiature cordless EMG devices. Bursts with amplitudes of more than 5%, 10%, 20% of the maximum voluntary contraction (MVC) value (EMG-burst-5%, EMG-burst-10%, and EMG-burst-20%) and episodes of sleep bruxism (EMG-episode) were selected for analyses. In all conditions for burst selection, the P-bruxer group showed a significantly larger number of bursts and episodes than those in the non-bruxer group. Accuracy of the clinical diagnosis criteria was 66.7% with the reference standard using EMG-burst-5%/h and 58.3% with that using EMG-episodes/h. By applying single-channel EMG as the reference standard, we were able to conduct validity tests of clinical diagnostic criteria with a larger sample. It was clarified that the level of accuracy of clinical diagnostic criteria for SB were not high despite using the combination of an interview and clinical findings.

Effect of masseter muscle activity during wakefulness and sleep on tooth wear

PURPOSE

To investigate the effect of masseter muscle activity during wakefulness and sleep on tooth wear.

METHODS

Sixteen participants with no or mild tooth wear (NMTW group) and sixteen participants with moderate-to-severe tooth wear (MSTW group) were enrolled. The severity of tooth wear was evaluated using the occlusal and incisal indices of the tooth wear index. Surface electromyography was performed to record the electrical activity of the left masseter muscle during wakefulness and sleep. Electromyographic activity was detected using an electromyographic threshold of 5% and 20% of maximal voluntary clenching (MVC). The total duration of electromyographic activity and bruxism episodes were calculated.

RESULTS

The mean ages of the NMTW and MSTW groups were 71.75 ± 7.61 years and 71.69 ± 7.49 years, respectively. The mean cumulative duration of electromyographic activity during wakefulness using a threshold of >5% MVC was 6.44 ± 4.52 min/h and 13.62 ± 10.08 min/h for the NMTW and MSTW groups, respectively (p=0.048). The mean total durations of electromyographic activity during wakefulness and sleep using a threshold of >20% MVC were 1.08 ± 1.70 min/h and 1.05 ± 3.02 min/h, respectively, in the NMTW group and 4.78 ± 6.37 min/h and 1.61 ± 1.79 min/h, respectively, in the MSTW group (p=0.048 and p=0.003, respectively).

CONCLUSION

These results suggest that masseter electromyographic activity during wakefulness and sleep may be related to the severity of tooth wear.

Occlusal problems, mental health issues and non-carious cervical lesions

Non-carious cervical lesions (NCCLs) are characterized by a loss of hard dental tissue near the cement-enamel junction with multifactorial etiology. The aim of this study was to demonstrate that occlusal factors as attrition, malocclusion, and bruxism, and mental disorders as depression, stress, and anxiety are involved in the etiology of NCCLs. Salivary samples and clinical data of 340 individuals selected from 6,112 participants were obtained from the University of Pittsburgh School of Dental Medicine Dental Registry and DNA Repository project. The affected group was formed by individuals with NCCL (34 females, 34 males, mean age 55.34 years). In addition, the comparison group was formed by individuals without NCCL (136 females, 136 males, mean age 55.14 years). Eleven single-nucleotide polymorphisms (SNPs) previously associated with mental disorders were genotyped and tested for association with NCCLs. When all occlusal factors were combined there was found a significant association with NCCL (p = 0.000001/adjusted OR 4.38, 95% CI 2.50-7.69). Attrition (OR 3.56, 95% CI 2.00-6.32) and malocclusion (OR 5.09, 95% CI 1.65-15.68) as separate variables showed statistically significant associations with NCCL. There was a significant difference in stress history between the two groups (OR 2.17, 95% CI 1.08-4.39). No associations between NCCLs and the SNPs selected were found. However, when the occlusal factors were analyzed as covariates, associations were found between bruxism and seven of the selected SNPs. Our results suggest that occlusal factors might be associated with NCCLs.

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.

Association between polysomnographic parameters of sleep bruxism and attrition-type tooth wear

BACKGROUND

Clinically, sleep bruxism is considered to be associated with the presence of tooth wear, but strong evidence is still lacking.

OBJECTIVE

To examine whether an association exists between polysomnographic parameters, recorded from patients with possible sleep bruxism and tooth wear.

METHODS

Sixty-three possible sleep bruxers (19 males and 44 females, mean ± SD age = 38.5 ± 11.4 years) were recruited among patients attending the Clinic for orofacial pain and dysfunction of the Academic Centre for Dentistry Amsterdam (ACTA). The incisal/occlusal tooth wear was recorded for each tooth clinically, using a 5-point ordinal scale. Subsequently, all patients underwent an one-night ambulatory polysomnographic recording, during which the number of bruxism episodes per hour of sleep (Epi/h), the number of bruxism bursts per hour of sleep (Bur/h), and the bruxism time index (BTI) were recorded and analysed. Logistic regression analysis was performed using the presence of tooth wear as the dependent variable, the polysomnographic recordings as independent variables, and corrected for age and gender. The Bur/h and BTI were removed from the analyses due to collinearity with the Epi/h. Additionally, the polysomnographic recordings were also tested for possible association with self-reported grinding of the teeth during sleep.

RESULTS

No significant correlation was found between tooth wear and Epi/h (P = 0.381). In addition, the presence of tooth wear was not associated with self-reported parafunctions.

CONCLUSION

Clinically measured tooth wear and self-reported parafunction seem not be related to the polysomnographic parameters of possible sleep bruxism.

Influence of the practice of sports, sleep disorders, and habits on probable sleep bruxism in children with mixed dentition

OBJECTIVE

Investigate the association between sleep disorders and probable sleep bruxism (SB) in children eight to ten years of age.

METHODS

A cross-sectional study was conducted with 739 schoolchildren in Brazil. Parents/guardians answered a sociodemographic questionnaire, the sleep disturbance scale for children, and the Circadian Energy Scale. Parafunctional habits were evaluated using the Nordic Orofacial Test-Screening. Multivariate logistic regression was performed (α = 5%), and a directed acyclic graph was used in the statistical model.

RESULTS

The prevalence of probable SB was 9.1% and 58.6% of the children had sleep disorders. In the final model, having unmarried parents/guardians (OR = 1.98; 95% CI: 1.07-3.65), exhibiting parafunctional habits (OR = 2.02; CI: 1.01-4.06), not practicing sports (OR = 1.92; CI: 1.04-3.54), sleep-wake transition disorders (SWTD) (OR = 2.01; 95%CI: 1.12-3.62), and excessive daytime sleepiness (EDS) (OR = 2.17; 95%CI: 1.11-4.29) were significant associated with probable SB.

CONCLUSION

The occurrence of probable sleep bruxism was influenced by the marital status of the parents/guardians, parafunctional habits, the non-practice of sports, and sleep disturbance (SWTD and EDS). This research contributes to the planning of public policies that include educational regimens at school to prevent sleep disorders and favor the reduction in sleep bruxism prevalence.

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.

Congenital and acquired defects in enamel of primary teeth: prevalence, severity and risk factors in Brazilian children

OBJECTIVE

This cross-sectional study evaluated the prevalence of tooth enamel defects and risk factors associated in primary dentition.

METHODS

A sample of 656 schoolchildren (population based), aged 4 years old, from Araraquara-SP (Brazil) was evaluated by two trained examiners according to the following indexes: Dental fluorosis (DF), deciduous molar hypomineralization (DMH), non-fluoride related developmental defects of enamel (DDE), tooth erosion and tooth attrition. Structured questionnaires identified socioeconomic condition, medical/dental history, behavior and dietary habits. Data were analyzed using Chi-square tests (p < 0.05).

RESULTS

Of the enamel congenital defects, DF was the most prevalent (6.1%, n = 40), followed by DMH (5.6%, n = 37). Of the acquired defects, attrition was the most prevalent (36.9%, n = 242), followed by erosion (2.4%, n = 16). The caries experience was similar between the affected children (29,5%; n = 94) and total sample (30.6%; n = 201). The etiological factors related to congenital defects were: not exclusively fed breast milk (p = 0.003) and jaundice at birth (p < 0.001); the association with acquired defects was found with vomiting frequent episodes (p = 0.037).

CONCLUSION

The general prevalence of enamel defects in primary dentition in Araraquara was 48.6%. Enamel defects may be associated with health-related factors and current lifestyle.

The interrelationship between xerogenic medication use, subjective oral dryness and tooth wear

OBJECTIVE

To investigate the association between xerogenic medication use and tooth wear among American adults and whether this association can be explained by subjective oral dryness.

METHODS

We used data from 3578 adults who participated in the National Health and Nutritional Examination Survey (NHANES). Tooth wear was clinically determined using the modified Tooth Wear Index. Information on xerogenic medication use, subjective oral dryness (amount of saliva in mouth and feeling the mouth dry when eating) and potential confounders (sociodemographic factors, dental insurance coverage, gastroesophageal reflux disease medication use and soft drinks intake) were self-reported. The associations among xerogenic medication use, subjective oral dryness and tooth wear were assessed in regression models adjusting for confounders.

RESULTS

Adults taking xerogenic medication had greater odds of reporting too little amount of saliva and feeling the mouth dry when eating. In addition, participants taking one and multiple (two or more) xerogenic medications had, respectively, 1.53 (95 % CI: 1.01-2.32) and 1.44 (95 % CI: 0.62-3.33) greater odds of having tooth wear than those taking no xerogenic medications. In a regression model including all explanatory variables, the association of xerogenic medication use with tooth wear was fully attenuated whereas subjective oral dryness (amount of saliva in mouth but not feeling the mouth dry when eating) remained positively associated with prevalence of tooth wear. Similar findings were obtained with long-term use of xerogenic medication (in the past month and for three or more years).

CONCLUSION

Current (last month) use of xerogenic medication was associated with the presence of tooth wear. This association was accounted for by subjective indicators of oral dryness.

CLINICAL SIGNIFICANCE

Dentists should be familiar with the possible connection between patient's medical prescription and tooth wear. Changing prescriptions to non-xerogenic alternatives, whenever possible, could improve patients' oral condition. The findings also suggest that patients may recognise, through the perception of dry mouth, when medication is placing them at risk.

Patient-based experiences with the use of an ambulatory electromyographic device for the assessment of masticatory muscle activity during sleep

Background

It is important to know how easy or difficult it is to use an ambulatory electromyographic (EMG) device for sleep bruxism assessment, and how this might affect its future utilisation.

Objective

To explore the experience of individuals using an EMG device that pairs with a smartphone app, in order to detect factors that could facilitate and/or hamper its utilisation in future scientific research.

Methods

Fifteen adults were recruited in the Orofacial Pain and Dysfunction Clinic of the Academic Centre for Dentistry Amsterdam (ACTA). Overnight recordings were performed in the home setting during one week. Time investment, feelings and thoughts, encountered difficulties and reasons for not using the device were assessed in a diary through open‐ended questions and 5‐point Likert scales. Content analysis of textual data was performed, and descriptives of quantitative data were calculated.

Results

Time investment was low (mean 10.2 minutes in the clinic, and 1.9 minutes per recording at home). Quantitative data showed an overall good experience (median of 4). Qualitative diary data showed that the desire to gain insight into one's masticatory muscle activity formed the main motivation to use the device. Device detachment and difficulty in using the app were the most prominent negative experiences.

Conclusion

The EMG device was well accepted for multiple overnight recordings. Curiosity for gaining insight into muscle activity was the most important factor that facilitated its use, and the app addressed this need. Device detachment and difficulties in using the app were the main factors that hampered its use.

A polysomnographic study on the relationship between sleep bruxism intensity and sleep quality

Objective: To evaluate the correlation between the Bruxism Episodes Index (BEI) that determines the number of bruxism episodes per hour of sleep and sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI).Methods: Seventy-seven participants (56 women and 21 men) in which probable sleep bruxism was diagnosed using guidelines of the American Academy of Sleep Medicine underwent video-polysomnography. Sleep quality was measured using PSQI.Results: The analysis showed the lack of a statistically significant correlation between the BEI and PSQI scores (p = 0.55). Analysis also showed that the study group (bruxers) and control group (non-bruxers) did not differ significantly in terms of PSQI scores (p = 0.88).Conclusion: The intensity of bruxism seems not to affect the quality of sleep. However, the topic of the relationship between sleep quality and the occurrence of sleep bruxism requires further research, taking into account co-occurring sleep disorders and sleep architecture.

Consensus-based clinical guidelines for ambulatory electromyography and contingent electrical stimulation in sleep bruxism

As yet, there are still no evidence‐based clinical diagnostic and management guidelines for ambulatory single‐channel EMG devices, like the BUTLER^® GrindCare^® (GrindCare), that are used in patients with sleep bruxism. Therefore, a consensus meeting was organised with GrindCare developers, researchers, and academic and non‐academic clinicians experienced with the use of ambulatory EMG devices. The aim of the meeting was to discuss and develop recommendations for clinical guidelines for GrindCare usage, based on the existing clinical and research experience of the consensus meeting's participants. As an important outcome of the consensus meeting, clinical guidelines were proposed in which an initial 2‐week baseline phase with the device in its inactive (non‐stimulus) mode for habituation and assessment of the number of jaw‐muscle activities is followed by a 4‐week active phase with contingent electrical stimuli suppressing the jaw‐muscle activities. As to avoid the commonly reported reduction in sensitivity to the stimuli, a 2‐week inactive phase is subsequently installed, followed by a repetition of active and inactive phases until a lasting reduction in the number of jaw‐muscle activities and/or associated complaints has been achieved. This proposal has the characteristics of a single‐patient clinical trial. From a research point of view, adoption of this approach by large numbers of GrindCare users creates a great opportunity to recruit relatively large numbers of study participants that follow the same protocol.

Non-carious lesions in patients treated for functional temporomandibular disorders

Introduction. Numerous clinical symptoms found in patients with temporomandibular disorders include non-carious lesions, such as V-shaped lesions, wear facets, enamel cracks, and impressions on the tongue or changes in the buccal mucosa. In addition, loosening and dislocation of teeth may occur.

Aim. The aim of the study was to obtain a clinical assessment of the prevalence and severity of non-carious lesions of dental hard tissues (attrition and abrasion) in patients treated for functional temporomandibular disorders.

Material and methods. The clinical research was performed among 45 patients of both genders, aged 16-38 years, treated at the Department of Functional Masticatory Disorders at the Medical University of Lublin, Poland. The study group consisted of 30 patients with diagnosed temporomandibular disorders. The control group included 15 individuals with no diagnosed temporomandibular disorders. The control group was selected using the method of analogues (considering age, gender and dental status). The examinations were performed before the treatment and twelve weeks after its beginning.

Results. The study found significantly higher values of the prevalence and severity of attrition in the patients group, in comparison with the control group (p < 0.05). In the case of abrasion, higher values of the studied variables of prevalence and severity of lesions in the patients, compared to controls, were also found, but the differences were not statistically significant (p > 0.05).

Conclusions. Attrition occurs more frequently and is more severe in patients with diagnosed temporomandibular disorders than in those without such diagnosis. However, no significant differences have been found in the prevalence and severity of abrasion in both groups.

Associations between tooth wear and dental sleep disorders: A narrative overview

Objectives

Tooth wear is a common finding in adult patients with dental sleep disorders. The aim of this paper was to review the literature on the possible associations between tooth wear and the following dental sleep disorders: sleep‐related oro‐facial pain, oral moistening disorders, gastroesophageal reflux disease (GERD), obstructive sleep apnoea syndrome (OSAS) and sleep bruxism.

Methods

A PubMed search was performed on 1 June 2018 using MeSH terms in the following query: Tooth Wear AND (Facial Pain OR Temporomandibular Joint Disorders OR Xerostomia OR Sialorrhea OR Gastroesophageal Reflux OR Sleep Apnea Syndrome OR Sleep Bruxism).

Results

The query yielded 706 reports on tooth wear and the mentioned dental sleep disorders. Several associations between tooth wear and the dental sleep disorders were suggested in the literature. It could be concluded that: (a) tooth wear is associated with dental pain and/or hypersensitivity; (b) oral dryness is associated with tooth wear, oro‐facial pain and sleep bruxism; (c) GERD is associated with tooth wear, oro‐facial pain, oral dryness, OSAS and sleep bruxism; (d) OSAS is associated with oral dryness, GERD and sleep bruxism; and (e) sleep bruxism is associated with tooth wear.

Conclusions

Tooth wear is associated with the dental sleep disorders oro‐facial pain, oral dryness, GERD and sleep bruxism. The dental sleep disorders are interlinked with each other, which leads to indirect associations as well, and makes the consequences of each single condition difficult to disentangle. Knowledge of these associations is clinically relevant, but more research is needed to confirm their validity.

Ultrasonographic evaluation of jaw elevator muscles in young adults with bruxism and with and without attrition-type tooth wear: A pilot study

OBJECTIVE

This pilot study was planned to analyze masticatory activation in bruxism patients with and without attrition by ultrasonographic evaluation of mandibular adductor muscles.

METHODS

Sixty bruxism patients (group 1: 30 without attrition, group 2: 30 with attrition) and an age-sex matched control of 30 (group 3) were clinically examined. The thickness of bilateral temporalis and masseter muscles during clench and rest was measured by ultrasonography.

RESULTS

The mean muscle thicknesses were higher in bruxing patients than in controls. In group 2, the clench/rest ratio (C/R) of the right and left masseter and temporal muscles were higher than the control group (p = 0.03, p = 0.01, p = 0.04, p = 0.03, respectively).

CONCLUSION

The thickness of chewing muscles increases with bruxism. The occlusal forces in the teeth increase, and therefore, the tooth wear increases. Ultrasonographic muscle thickness can be used to determine muscle activity in bruxism patients.

The effectiveness of an occlusal disclosure sheet to diagnose sleep bruxism: A pilot study

OBJECTIVE

To evaluate the utility of vacuum-pressed, BruxChecker^® sheets for the diagnosis of sleep bruxism.

METHODS

Twenty subjects participated in this study. Tooth contact during sleep was recorded using a 0.1 mm-thick polyvinyl chloride sheet called BruxChecker^®. The area of the BruxChecker^® in which the red dye was removed was measured. In addition, the EMG activity of the masseter muscle during sleep was recorded. The numbers of bruxism bursts and episodes were counted, and their correlations with the peeled area of the red dye on the BruxChecker^® were evaluated.

RESULTS

The number of bruxism bursts and episodes/hr significantly correlated with the peeled area at all cut-off values. The peeled area significantly correlated with the number of phasic type bruxism episodes but not with tonic or mixed type bruxism episodes.

DISCUSSION

Since the BruxChecker^® peeled area reflected phasic type sleep bruxism, the sheets may be useful in sleep bruxism screening.

Worning: Tooth Wear Ahead

While caries, periodontal disease and tooth wear are all largely preventable, current national guidelines on a preventive approach to oral healthcare provision are limited to advice on the prevention of caries and periodontal disease. Unfortunately, there is not yet a large enough body of evidence to develop guidelines on the prevention of tooth wear. As with caries, it is important to distinguish between 'active' and 'arrested' wear both in assessment and care planning. The aim of this article is to highlight the growing importance of early identification of patients who may be at risk of pathological tooth wear, provide an overview of known tooth wear markers, and suggest the development of a system to assess susceptibility to tooth wear.