Sleep bruxism; an overview of an oromandibular sleep movement disorder. REVIEW ARTICLE

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.

Effects of bruxism on temporomandibular joint internal derangement in patients with unilateral temporomandibular joint pain: The role of magnetic resonance imaging diagnostics

OBJECTIVE

This study compared temporomandibular joint (TMJ) magnetic resonance imaging (MRI) findings between bruxism and control groups with unilateral TMJ pain as well as the TMJ MRI findings for the painful and non-painful sides of individuals in the two groups.

METHODS

Clinical and MRI findings of patients seen at Uşak University, Dentistry Faculty, Department of Oral and Maxillofacial Surgery for unilateral TMJ pain between 2017 and 2020 were analyzed. Bruxism was diagnosed based on clinical findings and patient history. The MRI variables were disc/condyle relationship (normal, disc displacement with reduction, or disc displacement without reduction), disc structure (normal and abnormal), condyle degeneration type (normal, moderate, or severe), and joint effusion (absent or present). Pain was recorded based on a visual analog scale (VAS) numbered between 0 and 10. Statistical analyses were performed using IBM SPSS. The data were distributed non-normally according to the results of Kolmogorov-Smirnov tests. The Mann-Whitney U test was used to compare age and VAS. Chi-square tests were used to compare categorical variables. Statistical significance was defined as p < 0.05.

RESULTS

This study assessed the MRI records of 558 cases of TMJ pain. No significant differences in disc/condyle relation, disc structure, condyle structure, or effusion were observed between the control and bruxism groups (p > 0.05). However, a significant difference in TMJ MRI findings was observed between the painful and non-painful sides of each individual in the control and bruxism groups (p = 0.001, p < 0.001 and p = 0.004, p < 0.001, respectively).

CONCLUSION

The results of this study established a relationship between the painful side for each patient and TMJ MRI findings. In particular, individuals with bruxism had a higher rate of TMJ internal derangement and effusion on the painful side.

Students' awareness of the bruxism causes, effects and therapies

Objectives

Bruxism is a repetitive activity of the masticatory muscles characterized by clenching or grinding teeth and/or mandibular stiffening. Bruxism manifests itself in two forms: during sleeping and waking. The etiology of bruxism is multifactorial. The treatment of bruxism is mainly based on making the patient aware of the presence of the condition. The aim of the study was to assess knowledge on the causes and the effects of bruxism among Polish students as well as the possible management.

Materials and methods

The anonymous online survey was conducted among students (aged between 18 and 25 years old) of universities across Poland, using the Google Forms platform. The survey contained questions concerning bruxism causes, effects and therapies. All variants of answers in these questions contained true information about bruxism.

Results

The study found significant differences in awareness of bruxism among genders in favor of females. The awareness of bruxism among population residing in cities and in villages was comparable (p > 0.05). However, the results should be taken with care due to limited number of students that participated in the study and uneven gender distribution among urban and village residents.

Conclusions

Within the limitations of the study it can be concluded that the knowledge of bruxism among Polish students is higher in comparison with the findings from the literature, as well as the superiority of women's awareness of bruxism over men. Future studies should be conducted on greater student population, with even distribution of participants among country areas and variety of universities.

Significance

The findings may indicate the need for further education of male young adults, on bruxism causes, possible effects and therapies to increase their awareness of bruxism and encourage early diagnosis and treatment.

Obstructive sleep apnea: a follow-up program in its relation to temporomandibular joint disorder, sleep bruxism and orofacial pain

OBJECTIVE

To evaluate the correlation between obstructive sleep apnea (OSA) and temporomandibular joint (TMJ) morphology, tooth wear condition, orofacial pain through a follow-up program.

MATERIALS AND METHODS

Seventy one OSA patients were divided into three groups according to their (apnea hypopnea index) AHI: mild group (n = 23), moderate group (n = 24), and severe group (n = 24). All patients had OSA therapies around six months after confirm the diagnosis of OSA. The tooth wear score and orofacial pain condition of all patients were recorded via clinical examination. Cone beam computed tomography (CBCT) images were also taken when confirm the diagnosis of OSA (T0), 6 months after the diagnosis (T1), and 6 months after the OSA treatment (T2). Parameters indicating the condylar morphology and joint space were evaluated. The differences of clinical symptoms and TMJ conditions among T0, T1 and T2 time point were detected in the three groups respectively. The changes in T1-T0 and T2-T1 of all descriptions among three groups were also compared. The correlations between AHI and clinical symptoms were detected with Spearman correlation analysis.

RESULTS

In mild group, there was no difference in all clinical symptoms and TMJ morphology among the three time points. Both in moderate and severe group, the condylar volume, superficial area, wear score, visual analogue scales (VAS), and R value (indicating condyle position) displayed significant differences among the three time points (P < 0.05). From T0 to T1, mild group displayed fewer decreases in the condylar volume and superficial area and fewer increases in wear score than that in moderate and severe group (P < 0.05). From T1 to T2, there was a greatest reduction in severe group for R value, and significant difference in the description of VAS and R value were found among the three groups. AHI was negatively correlated condylar volume and condylar superficial area, and was positively correlated with tooth wear score and VAS (P < 0.05).

CONCLUSION

Moderate to severe OSA will aggravate orofacial pain and tooth wear, affect TMJ volume and superficial area, even change the location of condyles. Appropriate OSA therapies may be effective ways to alleviate these adverse effects in long-term.

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.

Association between 5-Hydroxytryptamine Receptor 2A Gene (rs6313 and rs4941573) Polymorphism and Sleep Bruxism: A Meta-analysis

Genetic factors may influence sleep bruxism's pathogenesis. Even though the association between the, 5-hydroxytryptamine 2A (5-HTR2A) serotonin receptor gene polymorphism and sleep bruxism has been investigated, inconsistent findings have been discovered. As a result, meta-analysis was performed to gather complete results on this topic. PubMed, Web of Science, Embase, and Scopus databases were searched for all papers containing English abstracts until April 2022. Medical Subject Heading (MESH) terms plus unrestricted keywords were used in the searches. The Cochrane test and the I ² statistic were used to determine the heterogeneity percentage in numerous researches. Comprehensive Meta-analysis v.2.0 software was used to conduct the analyses. Five properly fitting papers were chosen for meta-analysis from the 39 articles acquired during the initial search. The meta-analysis revealed that the 5-HTR2A polymorphism has no link with sleep bruxism susceptibility across the models studied (P-Value > 0.05). The combined odds ratio analysis revealed no statistically significant association between the 5-HTR2A gene polymorphism with sleep bruxism. Nonetheless, these findings require confirmation through researches with large sample sizes. Identifying genetic markers for sleep bruxism may help clarify and expand our current knowledge of bruxism physiopathology.

The effect of coffee and black tea consumption on sleep bruxism intensity based on polysomnographic examination

Background

Sleep bruxism (SB) is a common behavior that can result in various clinical consequences on human health. Risk factors for SB include among others emotional stress, anxiety, tobacco smoking, and excessive alcohol consumption. Coffee and black tea are among the most commonly consumed beverages worldwide. This study explores the influence of coffee and black tea consumption on bruxism intensity, as observed in polysomnographic examination.

Methods

Polysomnographic examination with simultaneous camera recording was conducted in 106 adult subjects. The results were evaluated according to guidelines set out by the American Academy of Sleep Medicine (AASM). The study group was divided according to habitual stimulant usage, as declared by the participants in a self-reported questionnaire. Four groups were identified: coffee drinkers versus non-drinkers and black tea drinkers versus non-drinkers.

Results

The bruxism episode index (BEI) was increased in coffee-drinkers as opposed to non-drinkers (4.59 ± 3.44 vs. 2.87 ± 1.50, p = 0.011). Sleep fragmentation, measured according to the arousal index, was comparable in coffee drinkers and non-drinkers. Electrolyte and lipid levels were similar in coffee drinkers and non-drinkers. Habitual black tea intake did not affect sleep architecture or bruxism intensity.

Conclusions

The study showed that habitual coffee consumption is a risk factor for the increased intensity of sleep bruxism. Neither coffee nor tea consumption is related to sleep fragmentation in habitual drinkers. Coffee and tea intake does not affect electrolyte and lipid concentrations. Caution should therefore be recommended in drinking coffee in people with sleep bruxism.

Pre-sleep affect predicts subsequent REM frontal theta in nonlinear fashion

Pre-sleep affect is thought to influence sleep, but associations with both sleep architecture and the electroencephalographic (EEG) power spectrum are mixed. In this pre-registered study, we assessed negative valence and arousal 1 h pre-sleep in 52 adults drawn from the community, then recorded one night of polysomnography (PSG) in participants' own homes. Pre-sleep affect was not associated with nonrapid eye movement (NREM) or rapid eye movement (REM) sleep architecture parameters, but we did observe inverted U-shaped relationships between both negative valence and arousal and REM frontal theta power, such that theta power was highest at moderate negative valence and arousal, and lowest at either affective extreme. When entered into a model together, both valence and arousal accounted for independent variance. Secondary analyses revealed a similar quadratic association with pre-sleep positive valence, suggesting a nonspecific effect of pre-sleep valence on REM frontal theta. Robustness checks confirmed that effects were not explained by homeostatic sleep pressure or sleep timing. Our results suggest that mixed findings in the literature may reflect different ends of a quadratic function, underscoring the importance of assessing how different components of pre-sleep affect relate to sleep.

Wear Management of Colored Foils for the Assessment of Sleep Bruxism Patterns-A Prospective, Randomized Crossover Study

The assessment of bruxism relies on clinical examinations, questionnaires, and polysomnography. The additional use of colored foils (BruxChecker^®) could enable a more precise evaluation of bruxing patterns. To assess differences between use of the foils during stress periods or just on consecutive nights and to determine a reasonable duration of using the foils, 28 patients were classified according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and were randomly assigned to wearing the 12 foils for six consecutive nights (alternately in the upper and lower jaw; "consecutive") or six nights within one month following days of high stress ("stress") in a crossover design. The sizes of the attrition areas were measured with ImageJ. Stress was evaluated using the Perceived Stress Scale. The Stress Coping Questionnaire (SVF-120) was used for assessing habitual stress coping strategies. Areas of attrition increased significantly from day 1/2 to 5/6, both for the upper and lower jaw. Molars in the mandible had significantly larger attrition areas than in the maxilla. No significant differences were detected between "consecutive" and "stress" phases. The foils were suitable for differentiating teeth more or less affected by bruxism and were able to show that areas of attrition increased with days, indicating that some adaptation takes place and several days of wearing the foils are required to show the full picture. However, no differences between low/moderate- and high-stress phases were detected.

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.

Are lower urinary tract conditions more common in children with sleep bruxism?

INTRODUCTION

Sleep bruxism is a parasomnia caused by rhythmic and non-rhythmic activity of the masticatory muscles during sleep. Prevalence of sleep bruxism is reported up to 40.6% in the literature. Sleep bruxism is a multifactorial issue and associated with multiple dental complications, sleep-related disorders, and psychosocial problems. We aimed to investigate if children with sleep bruxism suffer more from lower urinary tract conditions.

MATERIALS AND METHODS

Prospectively 128 children were included in this study. Sixty-four children constituted in the bruxism group and 64 children constituted in the control group. Children who admitted to the pediatric dentistry clinic with bruxism symptoms were recruited in the bruxism group. Control group constituted of consecutive 64 children who admitted to the pediatric dentistry clinic for routine dental examination. Parents were asked to fill out a questionnaire including Dysfunctional Voiding and Incontinence Scoring System (DVISS) form. Children's demographic data, presence of urinary frequency, presence of urgency, behaviour of voiding postponement, presence of daytime urinary incontinence, presence of enuresis nocturna, presence of fecal incontinence, presence of constipation, status of circumcision, and presence of bruxism related symptoms were recorded. Children with a DVISS score above 8 were considered to have functional voiding disorder. All children underwent a dental examination.

RESULTS

The mean age of children was 73.3 ± 26.9 months. For all children (n = 128), the girl to boy ratio was 40:88. Mean DVISS score was 2.5 ± 3.8 and the mean QOL score was 0.1 ± 0.4 for all children. Eight (6.3%) children were found to have functional voiding disorder based on the DVISS score. There was no statistically significant difference for any lower urinary tract condition between the bruxism group and the control group (Table). Children with bruxism significantly had more tooth wear and masseter muscle hypertrophy (<0.001 and < 0.05).

DISCUSSION

Sleep bruxism has been linked to a number of health issues including dental, systemic and psychosocial problems. Tooth wears, fatigue/pain in chewing muscles, gum recession, facial pain, masseter muscle hypertrophy and temporomandibular joint damage are the main complications of bruxism. Moreover, bruxism has been associated with systemic diseases and sypmtoms like asthma, respiratory illnesses, enuresis nocturna, anxiety, and stress.

CONCLUSIONS

Children with sleep bruxism suffer more from tooth wear, masseter muscle hypertrophy, and regional pain over the jaw. Additionally morning fatigue, relationship issues, and respiratory illnesses are more common in bruxist children. Lower urinary tract conditions are not more frequent in children with sleep bruxism.

A review of automated sleep disorder detection

Automated sleep disorder detection is challenging because physiological symptoms can vary widely. These variations make it difficult to create effective sleep disorder detection models which support hu-man experts during diagnosis and treatment monitoring. From 2010 to 2021, authors of 95 scientific papers have taken up the challenge of automating sleep disorder detection. This paper provides an expert review of this work. We investigated whether digital technology and Artificial Intelligence (AI) can provide automated diagnosis support for sleep disorders. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines during the content discovery phase. We compared the performance of proposed sleep disorder detection methods, involving differ-ent datasets or signals. During the review, we found eight sleep disorders, of which sleep apnea and insomnia were the most studied. These disorders can be diagnosed using several kinds of biomedical signals, such as Electrocardiogram (ECG), Polysomnography (PSG), Electroencephalogram (EEG), Electromyogram (EMG), and snore sound. Subsequently, we established areas of commonality and distinctiveness. Common to all reviewed papers was that AI models were trained and tested with labelled physiological signals. Looking deeper, we discovered that 24 distinct algorithms were used for the detection task. The nature of these algorithms evolved, before 2017 only traditional Machine Learning (ML) was used. From 2018 onward, both ML and Deep Learning (DL) methods were used for sleep disorder detection. The strong emergence of DL algorithms has considerable implications for future detection systems because these algorithms demand significantly more data for training and testing when compared with ML. Based on our review results, we suggest that both type and amount of labelled data is crucial for the design of future sleep disorder detection systems because this will steer the choice of AI algorithm which establishes the desired decision support. As a guiding principle, more labelled data will help to represent the variations in symptoms. DL algorithms can extract information from these larger data quantities more effectively, therefore; we predict that the role of these algorithms will continue to expand.

Probable awake bruxism - prevalence and associated factors: a cross-sectional study

Introduction:

Bruxism is defined as a repetitive activity of masticatory muscles, characterized by the clenching or grinding of the teeth, which can occur during wakefulness (awake bruxism) or during sleep (sleep bruxism).

Objectives:

The objectives of the present study were to determine the prevalence of awake bruxism and its associated factors.

Methods:

Sample was composed by 50 participants of both genders, aged between 18 and 60 years, submitted to a clinical examination - to observe the presence of tooth wear, marks on the mucosa, or masseter muscles hypertrophy - and self-applied questionnaires, which evaluated the presence of TMD signs and symptoms, oral behaviors, lifestyles, anxiety level and sleep quality.

Results:

The prevalence of awake bruxism was 48%. Its presence was statistically and significantly associated with the presence of signs and symptoms of TMD (p= 0.002), poor sleep quality (p = 0.032), buccal mucosa indentations (p < 0.001) and tongue (p = 0.011). Age, gender, social characteristics, habits (such as coffee ingestion, smoking, alcoholism and physical activity) and tooth wear were variables that had no significant association with awake bruxism.

Conclusions:

It was concluded that awake bruxism shows a high prevalence and a positive association with signs and symptoms of TMD and worst sleep quality. In addition, awake bruxism is more likely to occur in individuals who have buccal mucosa indentation and who present high rates of oral habits and oral behaviors.

Combined Effects of Botulinum Toxin Injection and Oral Appliance Therapy on Lower Facial Contouring: A Randomized Controlled Trial

(1) Background: Botulinum toxin (BoNT) injection is an esthetically effective and safe treatment for contouring the lower face. This study aimed to evaluate the combined effects of BoNT and supplementary oral appliance (OA) therapy on lower facial contouring. (2) Methods: We conducted a prospective randomized controlled trial from January 2015 to June 2016 at the Yonsei University Dental Hospital. Volunteers aged 20−45 years with masseter hypertrophy were randomly assigned to one of two groups: the non-OA group and the OA group. The non-OA group received BoNT injections alone, whereas the OA group received an OA in addition to BoNT injections. Changes in the bulkiest height of the lower face were evaluated by three-dimensional laser scanning before and 4, 8, 12, and 24 weeks after injections in both groups. (3) Results: In both groups, the bulkiest height reductions decreased, with a significant interaction between group (p = 0.046) and time (p < 0.001), although the overall reduction was at a similar level at 24 weeks. (4) Conclusions: The pattern of the bulkiest height reduction of the lower face after BoNT injection differed between standalone treatment and OA therapy, implying a normalizing effect of OA on masseter muscle activity.

The Effect of Severity of Obstructive Sleep Apnea on Sleep Bruxism in Respiratory Polygraphy Study

Obstructive sleep apnea (OSA) and sleep bruxism (SB) may appear concomitantly. Data on the relationship between OSA and SB are limited. It was shown that in a population with an increased risk of OSA, OSA was dependently correlated with SB on the degree of OSA severity only in mild and moderate cases of OSA. We aimed to confirm this relationship and affecting factors in a group of dental office patients in a prospective, observational study. Adult patients (n = 119) were evaluated using respiratory polygraphy. The risk of OSA was assessed using a STOP-Bang questionnaire (SBQ). The episodes of bruxism and respiratory events were scored according to the standards of the American Academy of Sleep Medicine. The prevalence of OSA and SB was found to be 63.02% and 41.17%, respectively. The bruxism episode index (BEI) was increased in the group with a higher risk of OSA (SBQ ≥ 3) compared to the group with a lower risk of OSA (3.49 ± 3.63 vs. 2.27 ± 2.50, p = 0.03). The sensitivity and specificity of the SBQ were not sufficient to predict SB. A positive linear correlation between AHI and BEI in the group with AHI < 23/h was found. The study confirmed that OSA was associated with SB in the group of patients with OSA and/or SB risk. The relationship between OSA and SB depended on the degree of severity of OSA and occurred in mild and moderate cases of OSA.

Prevalence and predictors of bruxism in two university clinic patient populations with dental implants: A cross-sectional analysis

OBJECTIVE

To analyze the prevalence, predictors, and prosthetic complications of bruxing patients with dental implants in two tertiary clinics in Istanbul, Turkey.

METHODS

Patients with at least one dental implant and with a fixed prosthesis were examined for the evidence of probable bruxism. Factors that could be related to bruxism were analyzed in relation to patient-specific variables. Technical and mechanical complications were investigated.

RESULTS

A total of 1688 patients were analyzed. The overall rate of probable bruxism was 19.72%. Besides self-reported bruxism (p < 0.022), antidepressant use (p < 0.002), frequent headaches (p < 0.014), and observation of linea alba (p < 0.028) were the predictors for probable bruxism. Technical and mechanical complications were frequent in the probable bruxers (p < 0.05).

CONCLUSION

Overall prevalence of bruxism was 19.72%, and bruxism was associated with general and gender-specific predictors.

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.

The Evaluation of the Relationship Between Oral Habits Prevalence and COVID-19 Pandemic in Adults and Adolescents: A Systematic Review

Background and Objective

The aim of this study was to systematically review the relationship between oral habits (bruxism- temporomandibular disorders) and COVID-19 pandemic in adults and adolescents.

Method and Material

A comprehensive search of the literature through PubMed, Scopus, Embase, google scholar and Cochrane databases was conducted. Such keywords as COVID-19, SARS-CoV-2, bruxism, adult, and adolescent were used.

Results

In the initial search 818 articles were obtained; 68 cases were duplicates and excluded. By reviewing the article title, 714 articles were removed because they were not relevant to the topic. The remaining articles were reviewed, and studies that did not meet the inclusion criteria, as well as letter to editors and expert opinions were excluded. Finally, 11 articles were allowed to enter the study. Out of 11 related articles, 5 studies were excluded from the present study due to mismatch of the target population; and finally 6 articles were thoroughly reviewed.

Conclusion

Studies have shown that stress caused by the COVID-19 pandemic increases detrimental oral habits such as bruxism as well as temporomandibular disorders in adults and adolescents; In general, young single women are at high risk and more exposed to these harmful oral habits.

Correlation between Bruxism and Gastroesophageal Reflux Disorder and Their Effects on Tooth Wear. A Systematic Review

Bruxism and gastroesophageal reflux (GERD) can lead to wear of the dental tissues. Wear has a mechanical or chemical origin, and it is of extrinsic or intrinsic type. Bruxism and GERD are two etiological factors of dental wear. The intrinsic mechanical wear (abfraction) of Bruxism and intrinsic chemical wear (erosion) of GERD are both involved in sleep disorders; indeed, they could have associations and act in synergy in dental wear. The purpose of this review was to find out the possible associations between bruxism and GERD and their effects on tooth wear. The research was conducted on PubMed and the Cochrane Library using the following Keywords/Mesh Terms: Tooth wear, Bruxism, Sleep Bruxism, Sleep Disorders, or GERD. Only systematic reviews and clinical studies performed exclusively on human subjects were included in the review. Initially, the research gave more than 630 results on dental wear, bruxism and GERD and after application of the inclusion criteria irrelevant studies were excluded, and 5 studies were finally included in this review. It was possible to observe the presence of some associations between the two problems (reflux and GERD) and hypothesize negative effects on tooth wear. This research revealed the presence of an interconnection between these three problems (reflux, GERD and tooth wear) that can further act in synergy by attacking the hard dental tissues both from a chemical (reflux) and mechanical (bruxism) point of view. The dentist could play a role of “sentinel” in a multidisciplinary team, intercepting these problems early in order to treat them in the most appropriate way. PROSPERO Registration Number: CRD42021234209.

Assessment of Telomerase Reverse Transcriptase Single Nucleotide Polymorphism in Sleep Bruxism

Introduction: Sleep bruxism (SB) is a widespread masticatory muscle activity during sleep and affects approximately 13.2% of the general population. Telomerase reverse transcriptase (TERT) plays a role in preventing the shortening of the telomere. This prospective, observational study aimed to investigate the relationship between single nucleotide polymorphism (SNP) of TERT and the severity of SB and to identify the independent risk factors for SB. Methods: A total of 112 patients were diagnosed by performing one-night polysomnography based on the guidelines of the American Academy of Sleep Medicine. TERT SNP was detected by real-time quantitative polymerase chain reaction (qPCR). Results: Statistical analysis showed the lack of relationship between the rs2853669 polymorphism of TERT and severity of SB (p > 0.05). However, the study showed that patients with allele T in the 2736100 polymorphism of TERT had a lower score on the phasic bruxism episode index (BEI). Based on the receiver operating characteristic (ROC) curve, the value of phasic BEI was 0.8 for the differential prediction for the presence of allele T in the locus. The sensitivity and specificity were 0.328 and 0.893, respectively. The regression analysis showed that lack of TERT rs2736100 T allele, male gender, and arterial hypertension are the risk factors for the higher value of phasic BEI. Conclusion: The SNP of the TERT gene affects phasic SB intensity. The absence of TERT rs2736100 T allele, male sex, and arterial hypertension are independent risk factors for phasic SB.

A Novel Quantitative Method for Tooth Grinding Surface Assessment Using 3D Scanning

Sleep bruxism is an oral parafunction that involves involuntary tooth grinding and clenching. Splints with a colored layer that gets removed during tooth grinding are a common tool for the initial diagnosis of sleep bruxism. Currently, such splints are either assessed qualitatively or using 2D photographs, leading to a non-neglectable error due to the 3D nature of the dentition. In this study we propose a new and fast method for the quantitative assessment of tooth grinding surfaces using 3D scanning and mesh processing. We assessed our diagnostic method by producing 18 standardized splints with 8 grinding surfaces each, giving us a total of 144 surfaces. Moreover, each splint was scanned and analyzed five times. The accuracy and repeatability of our method was assessed by computing the intraclass correlation coefficient (ICC) as well reporting means and standard deviations of surface measurements for intra- and intersplint measurements. An ICC of 0.998 was computed as well as a maximum standard deviation of 0.63 mm2 for repeated measures, suggesting an appropriate accuracy of our proposed method. Overall, this study proposes an innovative, fast and cost effective method to support the initial diagnosis of sleep bruxism.

Automatic Sleep-Stage Scoring in Healthy and Sleep Disorder Patients Using Optimal Wavelet Filter Bank Technique with EEG Signals

Sleep stage classification plays a pivotal role in effective diagnosis and treatment of sleep related disorders. Traditionally, sleep scoring is done manually by trained sleep scorers. The analysis of electroencephalogram (EEG) signals recorded during sleep by clinicians is tedious, time-consuming and prone to human errors. Therefore, it is clinically important to score sleep stages using machine learning techniques to get accurate diagnosis. Several studies have been proposed for automated detection of sleep stages. However, these studies have employed only healthy normal subjects (good sleepers). The proposed study focuses on the automated sleep-stage scoring of subjects suffering from seven different kind of sleep disorders such as insomnia, bruxism, narcolepsy, nocturnal frontal lobe epilepsy (NFLE), periodic leg movement (PLM), rapid eye movement (REM) behavioural disorder and sleep-disordered breathing as well as normal subjects. The open source physionet's cyclic alternating pattern (CAP) sleep database is used for this study. The EEG epochs are decomposed into sub-bands using a new class of optimized wavelet filters. Two EEG channels, namely F4-C4 and C4-A1, combined are used for this work as they can provide more insights into the changes in EEG signals during sleep. The norm features are computed from six sub-bands coefficients of optimal wavelet filter bank and fed to various supervised machine learning classifiers. We have obtained the highest classification performance using an ensemble of bagged tree (EBT) classifier with 10-fold cross validation. The CAP database comprising of 80 subjects is divided into ten different subsets and then ten different sleep-stage scoring tasks are performed. Since, the CAP database is unbalanced with different duration of sleep stages, the balanced dataset also has been created using over-sampling and under-sampling techniques. The highest average accuracy of 85.3% and Cohen's Kappa coefficient of 0.786 and accuracy of 92.8% and Cohen's Kappa coefficient of 0.915 are obtained for unbalanced and balanced databases, respectively. The proposed method can reliably classify the sleep stages using single or dual channel EEG epochs of 30 s duration instead of using multimodal polysomnography (PSG) which are generally used for sleep-stage scoring. Our developed automated system is ready to be tested with more sleep EEG data and can be employed in various sleep laboratories to evaluate the quality of sleep in various sleep disorder patients and normal subjects.

Evaluation of temporomandibular joint disorder in headache patients

OBJECTIVE

The present study is aimed at determining the percentage of temporomandibular joint disorder (TMD) in patients admitted to the neurology outpatient clinic with a headache complaint and to evaluate the association of TMD with the presence of bruxism and headache traits.

MATERIALS AND METHODS

A total of 349 headache patients were included in the study. The headache type, characteristics of the headache (incidence, duration, and severity of attacks), and the scores of the migraine disability scale (MIDAS) and Allodynia Symptom Scale (ASC-12T) were examined considering the presence of sleep bruxism. The International Classification of Headache Disorders (ICHD-3 Beta) criteria were used for diagnosing headaches. The presence of TMD was evaluated by using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). All patients diagnosed with TMD and/or bruxism were evaluated by a dentist.

RESULTS

A total of 349 patients, 259 females and 90 males, were included in the study. The mean age of the patients was 36 years. Primary and secondary headaches were diagnosed in 317 (90.80%) and 32 (9.20%) patients, respectively. In the primary headache group, there were 227 migraines (182 females, 45 males), 74 tension-type headaches (TTH) (48 females, 26 males), and 15 trigeminal autonomic cephalalgias (TACs) (7 females, 8 males) patients. The remaining patients were diagnosed with other types of diagnoses. The rate of patients with chronic headache was 86.50%. TMD was detected in 89 (25.50%) of the patients while sleep bruxism was present in 80 (23.30%) patients. TMD was detected in 68 (30.0%) migraine patients and 13 (17.60%) TTH patients. The rate of TMD was statistically significantly higher in migraine patients compared to the TTH patients (p=0.037).

CONCLUSION

Our cross-sectional outpatient-based study determined the incidence of TMD in headache patients as 25%. Among the primary headaches, the incidence of TMD was higher in migraine patients compared to the other diagnoses. Considering these data, the presence of TMD is a clinical condition that should be considered in the pathophysiology of headache, primarily migraine, and especially in cases of non-response to treatment.

Drug-Induced Bruxism: a Comprehensive Literature Review

Bruxism is a parafunctional teeth grinding activity that is attributed to be of multifactorial origin. The aim of this article is to provide a brief overview on drug-induced bruxism, commonly associated drugs, and its possible pathogenic mechanisms. Around 43 relevant publications were selected after a comprehensive search in PubMed, Cochrane library, Science Direct, and Google Scholar with appropriate keywords to collect data and compile this review. Disturbances in the neurotransmitters and their receptors in the central nervous system may play a significant role, particularly in sleep bruxism. Drugs that interfere normal secretion and function of neurotransmitters are documented to be capable of inducing bruxism. Such psychotropic drugs are being used in clinical practice chiefly for the management of mood disorders, anxiety, and depression. Although bruxism is a well-recognized side effect of certain medications, the extent of awareness about the same is still inadequate among dental professionals.

Self-reported sleep bruxism is associated with vitamin D deficiency and low dietary calcium intake: a case-control study

Background

Sleep bruxism may result in deleterious effects including loss of tooth enamel, fracture of teeth or restorations, teeth hypersensitivity or pain, and headache. The aim was to study the link between sleep bruxism, low serum vitamin D, low consumption of dietary calcium, psychological symptoms, and frequent headache.

Methods

This case-controlled study included 50 individuals with sleep bruxism and 50 age and gender matched controls. 25-hydroxyvitamin D was measured in serum. Hospital Anxiety and Depression Scale was used to measure anxiety and depression. Data about dietary calcium and frequent headache were self-reported.

Results

Participants with sleep bruxism had lower 25-hydroxyvitamin D and higher scores of anxiety and depression compared to controls (p < 0.05). Vitamin D deficiency, abnormal scores of anxiety and depression, low calcium consumption (< 323 mg/day), and frequent headache were reported in higher % of individuals with sleep bruxism compared to controls (p < 0.05). Binary logistic regression showed that sleep bruxism was significantly associated with vitamin D deficiency (OR = 6.66, p = 0.02), low consumption of dietary calcium (OR = 5.94, p = 0.01), and frequent headache (OR = 9.24, p < 0.001). Multiple linear regression showed that anxiety was significantly associated with decreased 25-hydroxyvitamin D (p = 0.03), increased scores of depression (p < 0.001) and female sex (p = 0.01). Binary logistic regression also showed that frequent headache was significantly associated with sleep bruxism (OR = 5.51, p < 0.01).

Conclusions

Sleep bruxism was associated with vitamin D deficiency and low consumption of calcium and was also associated with increased scores of anxiety and depression. Further investigations should be performed to check if vitamin D and calcium supplementation could relieve sleep bruxism.

Effects of photobiomodulation on auriculotherapy points for sleep disorders, anxiety, and temporomandibular dysfunctions

Objective: The purpose of this study was to evaluatephotobiomodulation applied at auriculotherapy points forsleep disorder (SD) and anxiety related to temporomandibulardysfunction (TMD).Methods: The study consisted of two groups of 20 participants: Auriculotherapy group (A) and Control Group(C). The participants responded to the RDC/TMD, Fletcher & Luckett questionnaires, and the Beck Anxiety Inventory to analyze TMD, SD, and anxiety before and after the treatment.Results: The participants presented scores corresponding to mild to moderateanxiety (MDN = 17; CI = [13.16;22.31]) and after treatment, normalor non-existent anxiety (MDN = 9; CI = [8.76; 17.12]) (p = 0.005). There was no significant difference (p > 0.05) between the controland 20 auriculotherapy groups for TMD and SD.Discussion: The results suggest that auriculotherapy was effective in the treatment of anxiety. However, it did not prove effective with the results of the SD and symptoms of TMD.

Bruxism, Related Factors and Oral Health-Related Quality of Life Among Vietnamese Medical Students

Although bruxism is a common issue with a high prevalence, there has been a lack of epidemiological data about bruxism in Vietnam. This cross-sectional study aimed to determine the prevalence and associated factors of bruxism and its impact on oral health-related quality of life among Vietnamese medical students. Bruxism was assessed by the Bruxism Assessment Questionnaire. Temporomandibular disorders were clinically examined followed by the Diagnostic Criteria for Temporomandibular Disorders Axis I. Perceived stress, educational stress, and oral health-related quality of life were assessed using the Vietnamese version of Perceived Stress Scale 10, the Vietnamese version of the Educational Stress Scale for Adolescents, and the Vietnamese version of the 14-item Oral Health Impact Profile, respectively. The prevalence of bruxism, sleep bruxism, awake bruxism, and both conditions in Vietnamese medical students were 51.2%, 38.2%, 23.4%, and 10.4% respectively. Stress, temporomandibular joint pain, masticatory muscle pain, and tooth attrition were associated with the presence of bruxism. Vietnamese medical students were negatively affected by bruxism in terms of oral health-related quality of life.

Over-the-counter bite splints: A randomized controlled trial of compliance and efficacy

Background

Occlusal splints are often used to curb the impacts of sleep bruxism (SB) on the dentition, and over‐the‐counter (OCT) options are becoming increasingly popular. OTC splints are usually fabricated at home by patients, but not routinely evaluated by dental professionals. It is unclear how OCT splints compare with more traditional splints that receive dental oversight.

Objectives

The present randomized controlled study tested how an OTC splint compared with a gold standard bite splint in terms of patient compliance (primary outcome) and efficacy (secondary outcomes).

Methods

Sixty‐seven subjects were randomly assigned to receive either the OTC (SOVA, N = 35) splint or the gold standard “Michigan” bite splint (MI, N = 32), with 61 completing the study (SOVA, N = 30; MI, N = 31). OTC‐splint subjects were required to fabricate their splints to clinically acceptable standards. Both groups wore the splints nightly for four months. Compliance was measured via daily diary. Efficacy outcomes evaluated stability, retention, periodontal health, night‐time rhythmic masticatory muscle activity (RMMA), and material wear.

Results

OTC‐splint subjects had difficulty fabricating splints to clinically acceptable standards. The number of night‐time RMMA bursts was significantly greater for the OTC splint group. Compliance and all other efficacy measurements were not significantly different between‐groups.

Conclusions

The results support the potential use of OTC splints for curbing the impacts of SB. However, the results strongly suggest that dentists should be actively engaged in overseeing patients' use of self‐fabricated appliances. This clinical trial is registered at ClinicalTrials.gov, Identifier number NCT02340663.

High separation anxiety trajectory in early childhood is a risk factor for sleep bruxism at age 7

STUDY OBJECTIVES

The evolution of sleep bruxism manifestations and their co-occurrence with separation anxiety in early childhood remain unclear. Our threefold aim was to: (1) describe developmental sleep bruxism trajectories in early childhood, (2) investigate co-occurrences between trajectories of sleep bruxism and separation anxiety, and (3) determine whether distinct trajectories of separation anxiety increase the risk of presenting sleep bruxism during the first year of elementary school.

METHODS

This study is part of the Québec Longitudinal Study of Child Development. Sleep bruxism scores were assessed from age 1.5 to 7 years with the Self-Administered Questionnaire for Mother (n = 1946). Separation anxiety scores were measured from age 1.5 to 6 years with the Interviewer-Completed Computerized Questionnaire (n = 2045).

RESULTS

We identified four sleep bruxism trajectories from age 1.5 to 6 years: High-Increasing sleep bruxism at age 1.5 (14.1%), High-Increasing sleep bruxism at age 4 (18.3%), Low-Persistent sleep bruxism (12.1%), and Never-Persistent sleep bruxism (55.5%); and four separation anxiety trajectories from age 1.5 to 6 years: Low-Persistent separation anxiety (60.2%), High-Increasing separation anxiety (6.9%), High-Decreasing separation anxiety (10.8%), and Low-Increasing separation anxiety (22.1%). Sleep bruxism and separation anxiety trajectories were weakly associated (X2 = 37.84, p < 0.001). Compared with preschoolers belonging to the Low-Persistent separation anxiety trajectory, preschoolers in the High-Increasing separation anxiety trajectory had almost double the risk of presenting sleep bruxism at age 7 (95% CI = 1.25-3.22, p = 0.04).

CONCLUSION

When separation anxiety issues are detected in early childhood, it would be useful to target sleep bruxism during the first year of elementary school.

Effect of laterotrusive occlusal scheme on chewing duration, external intercostal muscular activity, heart rate, and oxygen saturation

Objective: To evaluate the effect of the laterotrusive occlusal scheme on chewing duration, external intercostal (EIC) electromyographic (EMG) activity, heart rate (HR), and oxygen saturation (OS) during different tasks in the upright seated position.Methods: Fifty young participants, 25 with canine guidance and 25 with group function, were included. Chewing duration, bilateral EIC EMG activity, HR, and OS were recorded during the following tasks: 1) chewing until swallowing threshold; 2) laterotrusive teeth grinding.Results: Chewing duration, bilateral EIC EMG activity, HR, and OS showed no significant differences between the two laterotrusive occlusal schemes during the tasks studied.Conclusion: These results suggest that chewing duration, EIC muscle activity, HR, and OS were not significantly influenced by the laterotrusive occlusal scheme. Therefore, when a modification of the laterotrusive occlusal scheme is needed during oral rehabilitation or orthodontic treatment, canine guidance or group function should not significantly change EMG activity of EIC muscles.

Childhood Trauma, Quality of Life, Sleep Quality, Anxiety and Depression Levels in People with Bruxism

Introduction

The aim was to investigate the relation between sociodemographic features, anxiety, depression, sleep quality, childhood trauma experiences, and quality of life and bruxism determining the risk factors in people with bruxism.

Methods

A total of 200 people were included in the study. Of the patients, 100 were diagnosed with bruxism and 100 were included in the control group. Sociodemographic Data Form, Hospital Anxiety Depression Scale (HAD), The Pittsburgh Sleep Quality Index (PSQI), Childhood Trauma Scale (CTS), Short Form-36 Quality of Life Scale (SF-36) were used.

Results

While there was no significant difference between the case group and the control group in terms of age, gender, marital status, and working status, there was a significant difference between educational levels. When the groups were compared a significant difference was found with regard to HAD-A (p<0.05), HAD-D (p<0.01), PSQI (p<0.01) and CTS (p<0.05) scores. While a significant difference was found when KF-36 subscales were examined, with regard to Physical Function (p<0.01), Pain (p<0.05), Social Function (p<0.05) and Mental Health (p<0.01) scores, no significant difference was detected between the subscales of Role Strength (p>0.05), General Health (p>0.05), Vital Energy (p>0.05) and Emotional Role (p>0.05). Regression analysis shows, (PSQI), HAD-D CTS scores predicted bruxism.

Conclusion

Higher depression scale scores, bad sleep quality, traumatic childhood experiences increase the risk for bruxism. Paying attention to the mental state of people diagnosed with bruxism in the treatment process and incorporating the psychiatrists in this process may increase the success rate of the treatment.

Sleep bruxism and oral health-related quality of life in children: A systematic review

Sleep bruxism (SB) is a masticatory muscle activity during sleep that can cause several consequences to the stomatognathic system. This systematic review investigated the impact of SB on oral health-related quality of life (OHRQoL) of 0- to 6-year-old children. Literature search was undertaken through PubMed/MEDLINE, LILACS, Scopus, TRIP, Livivo databases, and grey literature. The search was conducted with no publication year or language limits. Two reviewers independently selected the studies, extracted the data and assessed the risk of bias. The quality of evidence was assessed using GRADE. From 185 potentially eligible studies, three were included in the review. All studies were conducted in Brazil, published between 2015 and 2017, and used the B-ECOHIS instrument to evaluate OHRQoL. Two studies found no association between SB and OHRQoL, whereas one showed a significant negative impact of SB on the OHRQoL of children. SB was associated with respiratory problems, presence of tooth wear, dental caries, malocclusion as well as income and pacifier use. Risk of bias ranged from moderate to high, and the quality of evidence was judged as very low. The evidence is currently insufficient for definitive conclusions about the impact of SB on OHRQoL of children.

Treatment of Sleep Bruxism With a Single Daily Dose of Buspirone in a 7-Year-Old Boy

Sleep bruxism is a temporomandibular joint dysfunction that could conclude in various problems including masseter muscle hypertrophy, headaches, and periodontal problems. Despite various treatment strategies, such as behavioral therapy, oral appliances, and pharmacotherapy, suggested, there is no specific treatment for this disorder. We present a 7-year-old boy whose sleep bruxism symptoms disappeared with a single daily dose of buspirone treatment in this report.

Determination of Inflammatory Markers, Hormonal Disturbances, and Sleepiness Associated with Sleep Bruxism Among Adults

PURPOSE

Sleep bruxism (SB) is characterized by repetitive phasic, tonic, or mixed masticatory muscle activity during sleep with multifactorial etiology. Previous studies have shown that the complex origin of SB can be related to the psychological features of the affected individual, consumption of caffeine and alcohol, smoking, obstructive sleep apnea, diabetes, increased body mass index, hypertension, thyroid diseases, and probable genetic vulnerability. This study aimed to investigate the inflammatory markers, hormonal disturbances, and sleepiness associated with SB, which have a potential effect on the total cardiovascular (CV) risk among relatively young and healthy patients.

PATIENTS AND METHODS

A total of 74 individuals with probable SB were subjected to single-night polysomnography, followed by blood panel and 24-h urinary excretion tests. The level of daytime sleepiness was assessed in the participants using the Epworth Sleepiness Scale.

RESULTS

SB was found in 78.4% of participants. The bruxism episode index (BEI) positively correlated with the concentrations of 17-hydroxycorticosteroids, C-reactive protein, and fibrinogen in the collected urine samples. A positive correlation was also found between phasic BEI and glucose concentration 2 h after the consumption of glucose solution. Sleep bruxers showed significantly increased sleepiness compared to nonbruxers (p = 0.02). The scores on sleepiness were positively correlated with mixed BEI, minimal oxygen saturation, and mean heart rate.

CONCLUSION

The results of this study revealed that participants with SB had metabolic and hormonal disturbances, probably due to stress and sympathetic activity. Moreover, it was found that young sleep bruxers potentially have a high CV risk due to the increased level of inflammatory and stress markers.

Assessment of the Pain, Stress and Emotional Factor Related to the Occurrence of Bruxism

Background/Aim: Bruxism is a parafunctional habit that has multiple etiology. Globally it is a widespread problem. The purpose of this study was to assess the presence of pain, stress and to understand the emotional factor and their relations to the occurrence of bruxism.

Material and Methods: For the purpose of this paper, 40 patients with partial edentuloissness and bruxism were treated prosthetically and with night dentures. They were assessed for the degree of the pain they feel and were given questionnaires for the level of stress they feel and for their psychological situation. The control group consisted of 40 patients who were not treated but were diagnosed with the same methods like the previous group.

Results: Patient feel pain from the consequences of bruxism, disregarding the statistical significance related to gender. Stress pays a major role as we live in a dynamic and demanding society. The more competitive and ambitious the person is the more there are possibilities for occurrence of bruxism. Emotions are a very complex matter that unconsciously can be connected to the presence of bruxism.

Conclusions: Besides prosthetic rehabilitation, sometimes a multidisciplinary approach is needed. Dentists should be aware of their role as psychiatrist and need to be educated of the principles of a patient’s analysis and of the cognitive behavioral therapy.

Psychosocial Predictors of Bruxism

OBJECTIVES

The study aimed to investigate the psychosocial predictors of bruxism. The association of various psychosocial factors such as alexithymia, emotional processing, state and trait anxiety, and stress with awake bruxism was analysed.

METHODS

The study involved 52 volunteers diagnosed with awake bruxism. The toolkit that was used included the Toronto Alexithymia Scale (TAS-20), the Emotional Processing Scale (EPS), the Cohen Perceived Stress Scale (PSS-10), and the State- and Trait-Anxiety Inventory (STAI), with independent individual psychological diagnoses being made for every patient. The results were statistically analysed using IBM SPSS Statistics 24.

RESULTS

The obtained data clearly show that psychological traits-both permanent dispositions (e.g., state anxiety and alexithymia) and temporary states (e.g., trait anxiety, emotional processing deficits, and psychological stress)-are significant determinants of awake bruxism. The percentage of explained variance indicates the presence of other factors as well.

CONCLUSIONS

Psychosocial factors such as state anxiety and trait anxiety, alexithymia, and perceived stress are as important as somatic causes in the occurrence and maintenance of awake bruxism. The profile of the obtained data suggests the possibility of preventing or minimizing the symptoms of awake bruxism through properly constructed psychoprophylactic interactions.

The Relationship between Sleep Bruxism and Obstructive Sleep Apnea Based on Polysomnographic Findings

Obstructive sleep apnea (OSA) is the most common sleep disorder. Sleep bruxism (SB) is a masticatory muscle activity during sleep that commonly co-occurs with OSA. The presented study aimed to assess this relationship and to identify factors affecting this co-occurrence. Adult patients (n = 110) were evaluated for OSA and SB in a sleep laboratory using polysomnography. The episodes of bruxism and respiratory events were scored according to the standards of the American Academy of Sleep Medicine. The prevalence of OSA and SB was found to be 86.37% and 50%, respectively. The bruxism episode index (BEI) was increased in the group with mild and moderate OSA (apnea–hypopnea index (AHI) <30) compared to that in the group with severe OSA (AHI ≥ 30) (5.50 ± 4.58 vs. 1.62 ± 1.28, p < 0.05). A positive correlation between AHI and BEI was observed in the group with AHI < 30. Regression analysis indicated that higher AHI, male gender, and diabetes were independent predictors for the increased BEI in group with AHI < 30. The relationship between OSA and SB depends on the degree of severity of OSA. OSA is correlated with SB in mild and moderate cases of OSA in the group of patients with increased risk of OSA.

Association between bruxism and temporomandibular disorders in children: A systematic review and meta-analysis

BACKGROUND

Bruxism in children and its relation to the development of temporomandibular disorders (TMD) has not been clearly determined yet.

AIM

The objective of this systematic review was to evaluate the possible association between bruxism and TMD in children.

DESIGN

Seven databases were searched, and 497 articles were assessed. Methodological quality was assessed through Newcastle-Ottawa Scale. The meta-analysis was performed with the articles in which extraction of data was possible and the summary effect measure through odds ratio (OR) and respective 95% confidence intervals (CIs). Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) was used to assess the certainty of evidence.

RESULTS

Ten cross-sectional studies were included in the systematic review. Of these, 8 showed a statistically significant association between bruxism and TMD. Seven studies however presented a high risk of bias. The meta-analysis was performed with 3 articles and obtained an OR of 2.97 (95% CI ranging from 1.72-5.15), indicating that children with bruxism are 2.97 times more likely to present TMD, with very low level of certainty defined by GRADE.

CONCLUSIONS

Although the studies showed high risk of bias, the qualitative analysis of individual studies showed that the children with bruxism have greater chance of developing TMD.

Presence of oral habits and their association with the trait of anxiety in pediatric patients with possible sleep bruxism

BACKGROUND

Bruxism is a repetitive masticatory muscle activity with a multifactorial etiology , that can be associated to emotional factors.

AIM

The aim of the study is to identify the presence of oral habits (OHs) and their association with the trait of anxiety (State-Trait Anxiety Inventory for Children [STAI-C]) in pediatric patients with possible sleep bruxism (PSB).

METHODS

Children between 3 and 12 years of age with PSB reported by their parents with complete deciduous or mixed dentition were included in the present study. Sociodemographic data (SD) as well as those on OHs such as only natural (ON), artificial breastfeeding (OA) or both (NA), finger sucking (FS), pacifier use (PC), and biting nails (BN) or objects (OB) were obtained through an interview with the parents/guardians answered the Brazilian version of the STAI-C questionnaire.

STATISTICAL ANALYSIS USED

SD and OH as well as STAI-C findings were descriptively evaluated, while the associations between OH and STAI-C with PSB were evaluated using the Chi-square test (P < 0.05).

RESULTS

The final sample was 52 children (6.62 ± 1.8 years). Of these, 51.9% were males, 82.7% reported not living in social risk areas, and 21.2% were only children. Considering the OH, patients participated in ON (26.9%), OA (9.6%), and both (63.5%); 13.5% had an FS habit and 46.2% had related PC use; and 80.8% were reported to have OB biting behaviors, while 53.8% participated in BN. The STAI-C was present in 25 (48.1%) patients with PSB and was not associated with the presence of OH.

CONCLUSION

There is no association between STAI-C and OH in pediatric patients with PSB.

Evaluation of Relationship Between Sleep Bruxism and Headache Impact Test-6 (HIT-6) Scores: A Polysomnographic Study

Sleep bruxism (SB) is a masticatory muscle activity during sleep characterized by teeth clenching or grinding and/or bracing or thrusting of the mandible. Morning headache is considered as a common symptom of SB; however, the relationship between SB and headache and its impact on patient's life is not clear. Therefore, the present study aimed to assess the relationship between SB using polysomnography with video/audio recording and Headache Impact Test-6 (HIT-6) scores. SB was evaluated in respondents by single-night diagnostic polysomnography with video/audio recording. The study found that Bruxism Episode Index was similar in the group with significant impact of headache on patient's life (HIT-6 score ≥ 50) and in group with little or no impact (HIT-6 score < 50). A statistically significant positive correlation was observed between bruxism associated with arousal and HIT-6 score (r = 0.51, p < 0.05) and between mixed bruxism and HIT-6 score (r = 0.58, p < 0.05) in the subgroup with phasic bruxism. The results indicated the relationship between SB and impact of severity of headache on the patient's life measured by HIT-6 is only modest. It was also found that the impact of severity of headache measured by HIT-6 is altered only in those with phasic bruxism and is associated with arousal. Further research should elucidate the factors influencing the relationship between SB and headache.

Trial Registration: Clinical Trials NCT03083405, WMU1/2017, https://clinicaltrials.gov/ct2/show/NCT03083405