Are there associations between sleep bruxism, chronic stress, and sleep quality?

Are sleep and awake bruxism associated with sleep quality and duration in adults? A systematic review and meta-analysis

The objective of this systematic review was to investigate the association between sleep quality with awake bruxism or sleep bruxism in adult individuals. Inclusion criteria comprised observational studies conducted in adults related to the research question, assessing bruxism by instrumental or non-instrumental approaches, and sleep quality by subjective or objective measures, or sleep duration. Sleep disorders, syndromes, neurological and psychiatric disorders, or psychotropic medications were excluded. PubMed, Embase, Web of Science, Scopus, Cochrane Library, and Google Scholar databases were searched until August 2024. Risk of bias was assessed by the JBI Critical Appraisal Checklist tool for cross-sectional studies, and the Newcastle-Ottawa scale for case-control studies. Independent meta-analyses comparing awake or sleep bruxism individuals with control individuals were performed when there were at least two studies for each sleep outcome. Thirty-two studies assessing a total of 4706 individuals were included. Meta-analyses showed no differences between sleep bruxism and control individuals regarding polysomnography parameters (sleep efficiency, sleep latency, awakenings, wake after sleep onset, and sleep duration). Pittsburgh Sleep Quality Index showed higher scores for sleep bruxism individuals compared to control individuals (MD = 1.98; 95 % CI = 0.96-3.00) and for awake bruxism individuals compared to control individuals (MD = 1.99; 95 % CI = 0.42-3.57). In total, 12 studies were rated as low risk of bias, 15 as moderate risk of bias, and 5 as high risk of bias. The certainty of evidence was rated as very low. Objective sleep quality was not associated with sleep bruxism, while subjective sleep quality was associated with both sleep and awake bruxism.

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

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

The relationship between possible, probable, or definite sleep bruxism and sleep quality: A systematic review

It has been suggested that sleep bruxism may interrupt sleep continuity, hence potentially influencing sleep quality. The aim of this study was to systematically review the relationship between possible, probable, and definite sleep bruxism and sleep quality in otherwise healthy individuals. A systematic search on sleep bruxism and sleep quality was performed in seven databases until 19 December 2022. Eligible articles were screened, and quality assessment was performed via the Joanna Briggs Institute Scale. Of 3681 articles screened, 13 were included in this study. Of these, six evaluated the relationship between sleep quality and possible sleep bruxism, three with probable sleep bruxism, and four with definite sleep bruxism. An association between poor sleep quality and sleep bruxism was found among those individuals diagnosed with possible and probable sleep bruxism. However, the studies conducted in individuals with definite sleep bruxism failed to demonstrate any association. With more reliable measures to evaluate sleep bruxism, a relationship between sleep bruxism and sleep quality was not evident.

The reports of specific waking-state oral behaviours, including awake bruxism activities, and psychological distress have a dose-response relationship: A retrospective medical record study

OBJECTIVE

To investigate if there are dose-response relationships between self-reported waking-state oral behaviours, including awake bruxism, and three indicators of psychological distress (depression, anxiety, stress).

METHODS

The study sample consisted of 1,886 patients with function-dependent TMD pain. Relationships between six non-functional and six functional waking-state oral behaviours, scored on a 5-point ordinal scale, and the psychological factors were investigated using ordinal logistic regression.

RESULTS

Mean age was 42.4 (±15.3) years, 78.7% being female. The odds of reporting the higher categories of non-functional oral behaviours depended on the severity of depression, anxiety, and stress. Most OR coefficients followed a quadratic dose-response distribution, the others increased linearly as the severity of the psychological scales increased. Almost no such associations were found with normal jaw function behaviours.

CONCLUSION

Within the limitations of this study, it may be concluded that non-functional waking-state oral behaviours, including awake bruxism, and psychological distress have a dose-response relationship, with higher levels of distress being associated with higher reports of oral behaviours.

Relationship between Sleep Bruxism Determined by Non-Instrumental and Instrumental Approaches and Psychometric Variables

Sleep bruxism (SB) can be determined with different diagnostic procedures. The relationship between psychometric variables and SB varies depending on the diagnostic method. The aim of the study was to compare the association between SB and oral health-related quality of life (OHRQoL; measured by the Oral Health Impact Profile, OHIP), anxiety (measured by the State-Trait anxiety inventory, STAI), and stress (single scale variable) depending on the diagnostic method in the same sample. N = 45 participants were examined by non-instrumental (possible/probable SB) and instrumental methods (definite SB). The OHIP differed significantly between possible SB (median = 4) and non-SB (median = 0) with W = 115, p = 0.01, and probable SB (median = 6) and non-SB (median = 0) with W = 101, p = 0.01). There was no significant difference in the OHIP score between definite SB and non-SB. For the other psychometric variables, the analyses revealed no significant differences between SB and non-SB in all diagnostic procedures. The results suggest that there is a difference between possible/probable and definite SB with respect to the association with OHRQoL. Certain aspects of possible/probable SB might be responsible for the poor OHRQoL, which are not measured in definite SB.

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

OBJECTIVE

The present study aimed to investigate the association between self-reported awake/sleep bruxism, and orofacial pain with post-traumatic stress disorder (PTSD).

METHODS

A case-control study with a convenience sample was designed. Participants were recruited from a university-based Trauma Ambulatory. The diagnosis of PTSD was established through a clinical interview and the Structured Clinical Interview (SCID-I/P). Thirty-eight PTSD patients and 38 controls completed the Research Diagnostic Criteria for Temporomandibular Disorders Axis-II to categorize awake/sleep bruxism and orofacial pain. Following this, we performed a short clinical examination of the temporomandibular joint and extraoral muscles.

RESULTS

Adjusted logistic regression analysis showed that awake bruxism was associated with PTSD (OR = 3.38, 95% CI = 1.01-11.27, p = 0.047). Sleep bruxism was not associated with any covariate included in the model. In a Poisson regression model, PTSD (IRR = 3.01, 95% CI = 1.38-6.55, p = 0.005) and the muscle pain/discomfort (IRR = 5.12, 95% CI = 2.80-9.36, p < 0.001) were significant predictors for current orofacial pain.

CONCLUSIONS

PTSD was associated with self-reported awake bruxism and low-intensity orofacial pain. These conditions were frequent outcomes in patients previously exposed to traumatic events.

CLINICAL RELEVANCE

We suggest including a two-question screening for bruxism in psychiatry/psychology interviews to improve under-identification and to prevent harmful consequences at the orofacial level.

Association between Psychological Distress and Possible, Probable, and Definite Sleep Bruxism-A Comparison of Approved Diagnostic Procedures

(1) Background: The relationship between sleep bruxism (SB) and psychological distress has been investigated in numerous studies and is heterogeneous. Different diagnostic procedures have been applied to determine SB. The aim of this study was to directly compare the association between psychological distress and SB diagnosed by different accepted methods. (2) Methods: Data of N = 45 subjects were analyzed, including group comparisons and correlation analyses. Following diagnostic methods for the determination of SB were used in one sample: self-report, clinical assessment, polysomnography with audio-video recording and a novel diagnostic sheet with analyzing software. Psychological distress was measured using the global severity index (GSI) of the Symptom Checklist-90-Standard (SCL-90-S). (3) Results: The GSI did not differ significantly between subjects with and without SB, regardless of the underlying diagnostic classification (p > 0.05). In-depth correlation analyses of self-report and clinical data revealed a weak-to-medium correlation with the GSI (r = 0.12-0.44). Due to non-normally distributed data, a test of statistical significance was not possible. Variables of instrumental methods such as the SB index (amount of SB activity per hour) of polysomnography (PSG) showed almost no correlation with psychological distress (r = -0.06-0.05). (4) Conclusions: Despite these limitations, the results provide an indication that the choice of diagnostic procedure may elucidate the variance in the correlation between SB and psychological distress.

Association Involving Possible Sleep Bruxism, Stress, and Depressive Symptoms in Brazilian University Students: A Cross-sectional Study

The aim of the present study was to examine the association regarding sleep bruxism (SB), depression, and stress in Brazilian university students. We conducted a cross-sectional study with a large-sample of university students ( n  = 2,089) in the city of Pelotas, Rio Grande do Sul, Southern Brazil. A self-administered questionnaire was sent to classrooms to evaluate socioeconomic and demographic characteristics. Possible SB was detected by self-report according to the International Consensus on The Assessment of Bruxism Criteria (2018). The Patient Health Questionnaire-9 and the Perceived Stress Scale were used to assess depression and stress symptoms respectively. Crude and adjusted Poisson regression analyses were performed. The prevalence of possible SB, high level of stress, and depressive symptoms in the sample were of 20.4%, 16.6%, and 16.6% respectively. Stress in female students was significantly associated with an increased prevalence of possible SB, but not in male students. Regarding depression, the prevalence of SB was 28% higher in students with depressive symptoms. Students with stress or depression had a 35% higher prevalence of SB than those without any symptoms. Conclusion  The findings have shown that university students with stress and depressive symptoms were more likely to be detected with possible SB.

The Role of Emotion Regulation, Affect, and Sleep in Individuals With Sleep Bruxism and Those Without: Protocol for a Remote Longitudinal Observational Study

BACKGROUND

Sleep bruxism (SB) is an oral behavior characterized by high levels of repetitive jaw muscle activity during sleep, leading to teeth grinding and clenching, and may develop into a disorder. Despite its prevalence and negative outcomes on oral health and quality of life, there is currently no cure for SB. The etiology of SB remains poorly understood, but recent research suggests a potential role of negative emotions and maladaptive emotion regulation (ER).

OBJECTIVE

This study's primary aim investigates whether ER is impaired in individuals with SB, while controlling for affective and sleep disturbances. The secondary aim tests for the presence of cross-sectional and longitudinal mediation pathways in the bidirectional relationships among SB, ER, affect, and sleep.

METHODS

The study used a nonrandomized repeated-measures observational design and was conducted remotely. Participants aged 18-49 years underwent a 14-day ambulatory assessment. Data collection was carried out using electronic platforms. We assessed trait and state SB and ER alongside affect and sleep variables. We measured SB using self-reported trait questionnaires, ecological momentary assessment (EMA) for real-time reports of SB behavior, and portable electromyography for multinight assessment of rhythmic masticatory muscle activity. We assessed ER through self-reported trait questionnaires, EMA for real-time reports of ER strategies, and heart rate variability derived from an electrocardiography wireless physiological sensor as an objective physiological measure. Participants' trait affect and real-time emotional experiences were obtained using self-reported trait questionnaires and EMA. Sleep patterns and quality were evaluated using self-reported trait questionnaires and sleep diaries, as well as actigraphy as a physiological measure. For the primary objective, analyses will test for maladaptive ER in terms of strategy use frequency and effectiveness as a function of SB using targeted contrasts in the general linear model. Control analyses will be conducted to examine the persistence of the SB-ER relationship after adjusting for affective and sleep measures, as well as demographic variables. For the secondary objective, cross-sectional and longitudinal mediation analyses will test various competing models of directional effects among self-reported and physiological measures of SB, ER, affect, and sleep.

RESULTS

This research received funding in April 2017. Data collection took place from August 2020 to March 2022. In all, 237 participants were eligible and completed the study. Data analysis has not yet started.

CONCLUSIONS

We hope that the effort to thoroughly measure SB and ER using gold standard methods and cutting-edge technology will advance the knowledge of SB. The findings of this study may contribute to a better understanding of the relationship among SB, ER, affect, and sleep disturbances. By identifying the role of ER in SB, the results may pave the way for the development of targeted interventions for SB management to alleviate the pain and distress of those affected.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/41719.

The association of cortisol/testosterone ratio and sleep quality with coronary heart disease: A case-control study in Chinese rural population

PURPOSE

There were limited studies that have probed into the combined effect of the cortisol/testosterone (C/T) ratio as a biomarker of stress and Pittsburgh Sleep Quality Index (PSQI) on coronary heart disease (CHD). This research aimed to explore the association of C/T ratio and PSQI with the risk of CHD in a rural Chinese population, as well as the interaction and combined effect between C/T ratio and PSQI on CHD.

METHODS

A case-control study was performed including 307 individuals without CHD and 307 patients drawn from Henan Rural Cohort. Logistic regression was utilized to survey the independent and joint effects of the C/T ratio and PSQI on CHD. To estimate the interaction impact of the C/T ratio and sleep quality (PSQI) on CHD, a cross-product term was introduced in the generalized linear model.

RESULTS

Higher C/T ratio and PSQI index scores are related to increased odds ratio for CHD (Odds ratios (ORs) and 95 % confidence interval (CI) were 1.17 (1.07, 1.29), p-trend < 0.001; 1.16 (1.09, 1.22), respectively). The odds ratio of C/T ratio for CHD increased with increasing PSQI in women (pinteraction = 0.018) and total population (pinteraction = 0.033). The combined group of high C/T ratio and high PSQI had the highest risk of CHD (Total: OR = 7.53, 95 % CI: 4.12-13.76).

CONCLUSIONS

The risk of CHD was associated with low testosterone levels, high C/T ratios, and high PSQI scores. Additionally, poor sleep quality aggravated the effect of high C/T ratio on coronary heart disease.

Effect of Tinnitus on Sleep Quality and Insomnia

Introduction  Tinnitus is a conscious perception of a sound resulting from abnormal activity within the nervous system. A relevant percentage of tinnitus patients report symptoms severe enough to significantly affect quality of life, including sleep disorders. Objective  To analyze the sleep quality, insomnia, daytime sleepiness, and risk of obstructive sleep apnea (OSA) in participants with tinnitus. Methods  The sample comprised 18 adults and older adults aged between 18 and 85 years old (mean age = 58.7 ± 17.5 years old), females and males, with complaint of continuous tinnitus for > 1 month. The instruments used were the Tinnitus Handicap Inventory (THI) questionnaire, the Insomnia Severity Index, the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, and the STOP-Bang questionnaire. Results  By means of the THI questionnaire, the tinnitus severity degree reported by most participants was mild (27.8%) and moderate (27.8%), having a positive (r = 0.582) and significant (0.011) correlation to sleep quality, measured by means of the Pittsburgh questionnaire. There was a positive correlation between the Insomnia Severity Index and tinnitus handicap (r = 0.499; p  = 0.035). A total of 72.2% of the participants self-assessed their sleep quality as poor, in addition to moderate insomnia (27.8%), although there is low risk of OSA (66.7%), without complaints of excessive daytime sleepiness (72.2%). Conclusion  Subjects with tinnitus complaint self-rated their sleep quality as poor. Moreover, the higher the reported tinnitus handicap, the greater the symptoms of insomnia. There was no influence of tinnitus in relation to daytime sleepiness and no relationship between the severity of tinnitus and the risk of OSA.

Associated factors and treatment options for sleep bruxism in children: an umbrella review

Data on clinical management options for sleep bruxism in the primary dentition are inconclusive. This umbrella review aimed to synthesize the available evidence from systematic reviews (SRs) on the associated factors and treatment approaches for clinical management of sleep bruxism in children. A search was conducted in the MEDLINE/PubMed, Web of Science, Embase, and OpenGrey databases up to March 2022. SRs published on sleep bruxism in children containing data on associated factors or treatment outcomes were included. The AMSTAR-2 tool was used to assess the methodological quality of SRs. The search identified 444 articles, of which six were included. Sleep conditions, respiratory changes, personality traits, and psychosocial factors were the associated factors commonly identified. Treatments included psychological and pharmacological therapies, occlusal devices, physical therapy, and surgical therapy. All SRs included presented a high risk of bias. Overlapping of the included studies was considered very high. The best evidence available to date for the management of sleep bruxism in children is based on associated factors, with sleep duration and conditions, respiratory changes, as well as personality traits and psychosocial factors being the most important factors commonly reported by studies. However, there is currently insufficient evidence to make recommendations for specific treatment options.

[Clinical efficiency of occlusive splints in the treatment of patients with temporomandibular joint dysfunction complicated by bruxism]

OBJECTIVE

Improving the effectiveness of treatment of patients with temporomandibular joint (TMJ) dysfunction complicated by bruxism.

MATERIAL AND METHODS

70 patients with signs of parafunction of the masticatory muscles were selected for the clinical study. The patients were divided into 2 groups of 35 people. Splints were made for patients from the groups using 2 different 3D printing methods. The treatment was monitored using clinical and instrumental studies, electromyography of the muscles themselves and computed tomography of the TMJ after 3, 6 and 12 months.

RESULTS

The severity of hypertonicity of the masticatory muscles decreased by the end of 3 months of treatment with the help of repositioning occlusal splints. After 6 months of treatment, the mean BEA decreased in both study groups, but to a lesser extent than in the first 3 months. After wearing a splint after 12 months, the decrease in muscle tone was insignificant.

CONCLUSION

The clinical use of positioning splints plays a crucial role in the stabilization of occlusion and is a mandatory stage of complex treatment of patients with pathology of the occlusal-musculoskeletal complex.

Association between Family Support, Stress, and Sleep Quality among College Students during the COVID-19 Online Learning Period

(1) Background: During the past 3 years, the COVID-19 pandemic has severely affected the normal school schedule of college students, jeopardizing their mental health, sleep quality, and interpersonal relationships. However, previous studies have focused on the dimension of social support received, and few studies have measured in depth the association of support received from family on adolescents’ physical and mental health. Therefore, this study explored the associations between family support received by Chinese college students during COVID-19 pandemic online classes, stress and sleep quality, and the mediating role of stress. (2) Methods: A cross-sectional study conducted at Chongqing Medical University recruited 712 college students through a university-wide incidental random sample using the Questionnaire Star platform. Statistical description and correlation analysis was conducted using SPSS 25.0, and structural equation modeling was constructed using AMOS 22.0 to test for mediating effects; (3) Results: The family support score of college students during the COVID-19 pandemic online course was 19.41 ± 4.62. Correlation analysis showed that sleep quality was negatively correlated with family support (r = −0.224, p < 0.01), positively correlated with stress (r = 0.324, p < 0.01), and family support was negatively correlated with stress (r = −0.159, p < 0.01). The results of structural equation modeling showed that stress partially mediated the relationship between family support and sleep quality among college students (indirect effect = −0.150, p < 0.01, SE = 0.013,95% CI = [−0.208, −0.064]). The model R2 was 36.4%. (4) Conclusions: Schools should consider implementing sleep education, and stress relief curriculum measures to improve the quality of students’ sleep, and should focus on the role that family plays during online classes. This will help students overcome the negative emotional effects of stress in the COVID-19 pandemic and improve their learning efficiency and physical and mental health.

Clinical factors affecting depression in patients with painful temporomandibular disorders during the COVID-19 pandemic

Temporomandibular disorders (TMD) are a multifactorial condition associated with both physical and psychological factors. Stress has been known to trigger or worsens TMD. We aimed to investigate whether the novel coronavirus disease-2019 (COVID-19) pandemic aggravates depression in patients with painful TMD, and the factors that affect their level of depression. We included 112 patients with painful TMD (74 females, 38 males; mean age: 35.90 ± 17.60 years; myalgia [n = 38], arthralgia [n = 43], mixed joint-muscle TMD pain [n = 31]). TMD was diagnosed based on the Diagnostic Criteria for TMD Axis I. Physical pain intensity was recorded using the visual analog scale (VAS); psycho-emotional status (depression: Beck Depression Inventory [BDI], anxiety: Beck Anxiety Inventory [BAI], and generalized stress related to COVID19: Global Assessment of Recent Stress [GARS]) was investigated twice (before [BC] and after COVID-19 [AC]). Additionally, factors affecting BDI-AC were investigated. BDI (p < 0.001), BAI (p < 0.001), GARS (p < 0.001), and VAS (p < 0.01) scores were significantly increased at AC than BC. The depression, anxiety, and stress levels were significantly positively correlated, and the AC and BC values of each factor showed a high correlation. In the mixed TMD group, BDI-AC was positively correlated with VAS-AC (p < 0.001). In the multiple regression analysis, clenching habit was the strongest predictor of an increase in the BDI scores from moderate to severe, followed by psychological distress, muscle stiffness, female sex, BAI-AC, and TMJ sounds. COVID-19 has negatively affected the psycho-emotional state of patients with painful TMD, and several clinical factors, including female sex and clenching habits, have influenced depression.

Comparison of factors affecting patients with a myofascial temporomandibular disorder with and without sleep bruxism

Aims and Background

The aim of the present study was to evaluate the relationship between jaw function, neck disability, sleep quality, fatigue, and headache in patients with myofascial temporomandibular disorder (TMD) with sleep Bruxism (SB) and without it (non-SB).

Subjects and Methods

This case-control study was conducted with a total of 200 myofascial TMD patients, comprising 91 identified as SB and 109 as non-SB. The Jaw Function Limitations Scale (JFLS), Neck Disability Index (NDI), Pittsburgh Sleep Quality Index (PSQI), Fatigue Severity Scale (FSS), and Headache Impact Test-6 (HIT-6) scales and indexes were used.

Results

In the group with SB compared to the non-SB group, JFLS, NDI, PUKI, and FSS scores were statistically significantly higher (P < 0.001). No statistically significant difference was found between the groups in terms of visual analog scale (VAS) (P = 0.127) and HIT-6 scores (P = 0.365). The probability of having JFLS in patients with SB compared to those without was folded 3.551 times (P = 0.002), and the probability of having NDI increased 3.473 times (P = 0.002). In addition, SB was observed to trigger poor sleep quality (P < 0.001). There was no statistically significant determinant of bruxism on FSS (P = 0.196), and on HIT-6 (P = 0.488).

Conclusion

It can be concluded that SB causes limitation of the jaw's functional activities, neck problems, and decreased sleep quality in myofascial TMD. These findings emphasize the importance of considering SB when evaluating and treating patients with myofascial TMD problems.

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.

Sleep Bruxism: An Integrated Clinical View

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

Cancer and stress: NextGen strategies

Chronic stress is well-known to cause physiological distress that leads to body balance perturbations by altering signaling pathways in the neuroendocrine and sympathetic nervous systems. This increases allostatic load, which is the cost of physiological fluctuations that are required to cope with psychological challenges as well as changes in the physical environment. Recent studies have enriched our knowledge about the role of chronic stress in disease development, especially carcinogenesis. Stress stimulates the hypothalamic-pituitaryadrenal (HPA) axis and the sympathetic nervous system (SNS), resulting in an abnormal release of hormones. These activate signaling pathways that elevate expression of downstream oncogenes. This occurs by activation of specific receptors that promote numerous cancer biological processes, including proliferation, genomic instability, angiogenesis, metastasis, immune evasion and metabolic disorders. Moreover, accumulating evidence has revealed that β-adrenergic receptor (ADRB) antagonists and downstream target inhibitors exhibit remarkable anti-tumor effects. Psychosomatic behavioral interventions (PBI) and traditional Chinese medicine (TCM) also effectively relieve the impact of stress in cancer patients. In this review, we discuss recent advances in the underlying mechanisms that are responsible for stress in promoting malignancies. Collectively, these data provide approaches for NextGen pharmacological therapies, PBI and TCM to reduce the burden of tumorigenesis.

Association between sleep bruxism and stress symptoms in adults: A systematic review and meta-analysis

To synthesise and critically review the association between sleep bruxism (SB) and stress symptoms in adults. A systematic review was performed. The search was completed using seven primary electronic databases in addition to a grey literature search. Two reviewers blindly selected studies based on pre-defined eligibility criteria. Risk of bias of the included articles was performed using the Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross-Sectional Studies. RevMan 5.4 was used to perform the meta-analysis. The quality of evidence was evaluated according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Ten studies were included for qualitative analysis, of which three were included for quantitative analysis. Three studies were evaluated to have low risk of bias, and seven were assessed with moderate risk of bias. Quality of evidence was classified as very low for all outcomes. Individuals with SB were found to have higher levels of some self-reported stress symptoms as assessed through questionnaires with a mean difference of 4.59 (95% CI 0.26-8.92). Biomarkers like epinephrine, norepinephrine, cortisol, adrenaline, dopamine, noradrenaline and prolidase enzyme levels also showed a positive association with SB. Although some associations were identified between probable SB and self-reported stress symptoms and biomarkers of stress in adults, given that the quality of evidence was found to be very low, caution should be exercised in interpreting these results. These findings suggest that additional and better designed studies are warranted in order to clarify the link between SB and stress.

Self-reported sleep bruxism among Finnish symphony orchestra musicians: Associations with perceived sleep-related problems and psychological stress

Objective: This study aimed to evaluate whether self-reported sleep bruxism among musicians is associated with sleep-related problems and/or psychological stress.Methods: Eight hundred-thirty-one Finnish orchestra musicians completed a questionnaire that covered, among others, indicators of sleep-related problems, possible sleep bruxism, and stress.Results: In total, 488 questionnaires were completed. The single variable ordinal logistic regression models revealed at least moderate associations between frequency of sleep bruxism and female gender, shorter sleep duration, longer sleep latency, problems in sleeping during concert season, feeling more often tired during the daytime, restless legs, a poor self-rated sleep quality, and more stress experience. The variables that remained in the final model were sleep duration, gender, and stress.Conclusion: Musicians who sleep 7 hours or less per night report more sleep bruxism, as compared to those who sleep 8 hours or more. Female gender and high-stress experience were associated with more sleep bruxism.

Sleep Disorders in Individuals With High Risk for Diabetes in Indian Population

Background:

Sleep restores physiology and neurochemical components of our body and is essential for physical and mental health. Sleep disorders (SDs) are associated with insulin resistance and metabolic disorders. The association between SDs and diabetes needs to be understood in the Indian population.

Purpose:

The purpose was to investigate the association between SD and diabetes in the Indian population.

Methods:

As a part of nationwide Niyantrita Madhumeha Bharata Abhiyaan-2017 (NMB-2017), a cross-sectional study was conducted and data was collected from seven zones of India, after screening through the Indian Diabetes Risk Score (IDRS). The sleep quality was assessed on a scale of 1 to 4 (very good = 1, very bad = 4). The time taken to fall asleep (sleep latency) was assessed on a scale of 0 to 5 (“0” = nil and “5” = >1.5 h). Stress was assessed by the perceived stress scale.

Results:

Bad sleep quality was positively (odds ratio 1.055, CI [1.001, 1.113], and P < .01) associated with self-reported known diabetes. Increased time taken to fall in sleep (sleep latency) was associated significantly with IDRS high risk (odds ratio 1.085, CI [1.008, 1.168], and P = .01), with an average sleep latency /time takes to fall in sleep (maximum range 5 [>1.5 h], mode 2 [10 to 30 min]) minutes. Moderate stress was significantly associated with bad sleep quality (odds ratio 1.659).

Conclusion:

A positive association of bad sleep quality and stress with diabetes, and an increased sleep latency in the IDRS high-risk population point to the role of modifiable risk factors. Behavioral modification and stress reduction by using yoga may be beneficial in the better management of diabetes.

Bruxism Throughout the Lifespan and Variants in MMP2, MMP9 and COMT

Bruxism is a masticatory muscle activity characterized by grinding of the teeth and clenching of the jaw that causes tooth wear and breakage, temporomandibular joint disorders, muscle pain, and headache. Bruxism occurs in both adults and children. Clinical characteristics and habits were evaluated in an adult sample. Moreover, we used DNA samples from 349 adults and 151 children to determine the presence of association with specific genes. Genomic DNA was obtained from saliva. The markers rs2241145 and rs243832 (metalloproteinase 2 (MMP2)), rs13925 and rs2236416 (metalloproteinase 9 (MMP9)), and rs6269 (cathecol-o-methyltransferase (COMT)) were genotyped. Data were submitted to statistical analysis with a significance level of 0.05. In adults, in univariate logistic regression, presence of caries, attrition, and use of alcohol were increased in bruxism individuals (p < 0.05). In addition, in adults, there was an association between bruxism and MMP9 (rs13925, p = 0.0001) and bruxism and COMT (rs6269, p = 0.003). In children, a borderline association was observed for MMP9 (rs2236416, p = 0.08). When we performed multivariate logistic regression analyses in adults, the same clinical characteristics remained associated with bruxism, and orthodontic treatment was also associated, besides rs13925, in the AG genotype (p = 0.015, OR_a: 3.40 (1.27-9.07)). For the first time, we provide statistical evidence that these genes are associate with bruxism.

Correlations between Sleep Bruxism and Temporomandibular Disorders

The aim of this study was to identify correlations between sleep bruxism (SB) and temporomandibular disorders (TMD) as diagnosed by means of the research diagnostic criteria for temporomandibular disorders (RDC/TMD). Sleep bruxism was diagnosed on the basis of I) validated questionnaires, II) clinical symptoms, and III) electromyographic/electrocardiographic data. A total of 110 subjects were included in the study. Fifty-eight patients were identified as bruxers and 52 as nonbruxers. A psychosocial assessment was also performed. An RDC/TMD group-I diagnosis (myofascial pain) was made for 10 out of 58 bruxers, whereas none of the nonbruxers received a diagnosis of this type. No significant differences were found between bruxers and nonbruxers with regard to RDC/TMD group-II (disc displacement) and group-III (arthralgia, arthritis, arthrosis) diagnoses. Somatization was significantly more common among bruxers than nonbruxers. Multivariate logistic regression analysis revealed that somatization was the only factor significantly correlated with the diagnosis of myofascial pain. The results of this study indicate a correlation between myofascial pain, as diagnosed using the RDC/TMD, and somatization. It seems that somatization is a stronger predictor of an RDC/TMD diagnosis of myofascial pain than sleep bruxism is.

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.

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.

Correlation between Sleep Bruxism, Stress, and Depression-A Polysomnographic Study

Background and objectives: Sleep bruxism is a common phenomenon that can affect approximately 13% of adult population. It is estimated that bruxism can be caused by three types of factors: biological, psychological, and exogenous. There are many scientific reports about the coexistence of bruxism, stress, and psychoemotional disorders. The aim of this study is to evaluate the possible correlation between occurrence of sleep bruxism and perceived stress and depressive symptoms. Material and methods: The material of this study consisted of 77 patients of Clinic of Prosthetic Dentistry operating at the Department of Prosthetic Dentistry, Wroclaw Medical University, Poland in which after using guidelines of the American Academy of Sleep Medicine probable sleep bruxism was fund. Patients then underwent video-polysomnography. Exposure to perceived stress was evaluated with Perceived Stress Scale-10 (PSS-10). Occurrence of depressive symptoms was evaluated with Beck’s Depression Inventory (BDI). Results: The analysis showed lack of statistically significant correlation between Bruxism Episodes Index (BEI) and Perceived Stress Scale–10 and Beck’s Depression Inventory scores (p = 0.64, p = 0.65; respectively), also when comparing study group (bruxers) and control group (non-bruxers) (p = 0.88, p = 0.77; respectively). Conclusion: Intensity of sleep bruxism was not statistically significantly correlated with self-reported perceived stress and depression. This issue requires further research.