Polysomnographic Assessment of Effects of Tobacco Smoking and Alcohol Consumption on Sleep Bruxism Intensity

Effects of the low Fowler's sleep position and methazolamide treatment on sleep bruxism: A randomized controlled trial

Intracranial pressure is one of the determinants of sympathetic activities, and sleep bruxism is associated with increased sympathetic activities. This study aimed to investigate effects of the low Fowler's sleep position and methazolamide treatment on the occurrence of rhythmic masticatory muscle activities/sleep bruxism episodes in patients with sleep bruxism in a randomized controlled trial. Polysomnographic recordings were performed on the patients with sleep bruxism sleeping in the low Fowler's (15°-30°) or supine position (n = 11), and with methazolamide or placebo treatment (100 mg, 3-4 hr before bedtime, P.O., n = 9), and changes in sleep variables and heart rate variance during sleep in the low Fowler's position or with methazolamide treatment were determined. Sleep bruxism index, number of masseter muscle electromyographic bursts per hour of sleep, ratio of rhythmic masticatory muscle activities/sleep bruxism duration to the total sleep duration, index of total limb movements, index of limb movements with rhythmic masticatory muscle activities, and number of sleep bruxism clusters per hour of sleep in the low Fowler's position and after methazolamide intake were significantly smaller (p < 0.05-0.001) than those in the supine position and after placebo intake, respectively. The low-frequency heart rate variance powers during non-rapid eye movement sleep stage 2 (N2) in the low Fowler's position and with methazolamide treatment were significantly lower (p < 0.05) than those during sleep in the supine position and with placebo treatment, respectively. In conclusion, sleep in the low Fowler's position and methazolamide treatment were associated with significant decreases in the occurrence of rhythmic masticatory muscle activities/sleep bruxism episodes, which might be due to a reduction in intracranial pressure and sympathetic activities mainly during non-rapid eye movement sleep stage 2.

Why am I grinding and clenching? Exploration of personality traits, coping strategies, oral parafunctional behaviors, and severe sleep bruxism in a polysomnographic study

Introduction

Causal relationships between psychopathological symptoms, personality traits, coping mechanisms, and sleep bruxism (SB) were studied in the past, giving inconsistent results mostly based on self-assessment evaluations. This polysomnography-based cross-sectional study aimed to explore the relationships between severe SB, personality traits (according to the Big Five model), and coping strategies with objective polysomnographic verification.

Methodology

The study included 66 participants divided into severe SB (SSB) (n=32) and no or mild SB (n=34) groups based on video-polysomnography performed in the sleep laboratory. Questionnaire assessment included the use of the Beck Depression Inventory, Beck Anxiety Inventory, Mini-COPE, International Personality Item Pool Big Five Markers 20-Item version, and Oral Behavior Checklist.

Results

Participants with SSB presented with fewer self-reported anxiety (p=0.008) and depressive (p=0.01) symptoms than the non- or mild-SB groups. The SSB group scored significantly higher in Big Five personal traits such as extraversion (p=0.007), emotional stability (p=0.013), and intellect (p=0.004), while regarding coping strategies, the SSB group was less likely to use negative strategies: self-distraction (p=0.036), denial (p=0.006), venting (p=0.03), behavioral disengagement (p=0.046), and self-blame (p=0.003), and turning to religion (p=0.041). The intensity of oral parafunctional behaviors was comparable in both groups (p=0.054). Emotional stability was a moderate protective factor (p=0.004), and the self-blame strategy was a strong risk factor (p<0.001) for increased oral parafunctional behavior intensity. Phasic activity negatively correlated with anxiety symptom severity (p=0.005), whereas tonic (p=0.122) and mixed (p=0.053) phenotypes did not. SB intensity was a protective factor against anxiety symptoms (p=0.016).

Conclusion

In terms of psychopathology, severe sleep bruxers tend to present less severe anxiety and depressive symptoms, while some of their personality traits (extraversion, emotional stability, and intellect) were more strongly pronounced. SSB is possibly related to the lesser use of the "maladaptive" coping strategies and there were no specific coping strategies preferred by SSB participants, compared to the other group. These observations require further studies, as it should be determined whether SB (especially phasic activity) might be a form of a somatization/functional disorder. Further research should focus on the psychogenic background of oral parafunctional behaviors, which occur more often in less emotionally stable personalities and in people using self-blame coping strategies.

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.

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

BACKGROUND

Bruxism, a common oral parafunctional behavior characterized by the grinding or clenching of teeth, is a multifactorial condition with potentially detrimental effects on oral health and overall well-being. In recent years, there has been growing interest in understanding the relationship between bruxism and alcohol abuse, as both are prevalent issues that may share underlying factors and exacerbate each other. This systematic review, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, aims to evaluate the frequency of bruxism among individuals with alcohol abuse.

METHODS

A comprehensive search of electronic databases, including PubMed, Lilacs, Scopus and Web of Science, will be conducted to identify relevant studies published up to the knowledge cutoff date in January 2023. The search strategy will include keywords related to bruxism, alcohol abuse, and their synonyms. Inclusion criteria will encompass original research studies, such as observational, cross-sectional, cohort, and case-control studies, as well as clinical trials, that examine the relationship between bruxism and alcohol abuse. Two independent reviewers will perform the study selection, data extraction, and quality assessment, with discrepancies resolved by consensus.

RESULTS

The systematic review will present a summary of the identified studies, including the study design, characteristics of the study populations, and key findings related to the association between bruxism and alcohol abuse. The potential mechanisms underlying this relationship will also be explored. Subgroup analyses and the quality of evidence will be assessed. Finally, the implications of this association for clinical practice and further research will be discussed.

CONCLUSIONS

This systematic review will contribute to a better understanding of the interplay between bruxism and alcohol abuse, shedding light on potential risk factors, mechanisms, and clinical implications. The findings may have significant implications for the prevention, management, and treatment of bruxism, particularly in individuals with a history of alcohol abuse.

Systematic Review on the Link between Sleep Bruxism and Systemic Chronic Inflammation

Sleep bruxism (SB) is a sleep-related behavior characterized as rhythmic (phasic) or non-rhythmic (tonic) masticatory muscle activity. SB is a common sleep behavior with a predominantly central origin. The aim of this systematic review was to evaluate the relationship between inflammatory status and SB according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 (PRISMA 2020). The research was registered at PROSPERO (CRD42023395985). We performed a systematic literature analysis using five different databases. Furthermore, the backward snowballing technique was applied to identify additional papers. Initially, 28 papers were screened from the database search, and 162 papers were revealed in the backward snowballing process. Eventually, five articles were included. Data concerning the inflammatory status of patients experiencing SB were investigated and summarized. Due to the heterogeneity of the compared studies, only a qualitative comparison and narrative summary were performed. The results suggest that SB could be associated with systemic inflammation. In fact, this systematic review revealed that there are no papers conclusively showing that the inflammatory status in bruxers is comparable to non-bruxers. However, each of the examined studies utilized different methods of assessing systemic inflammation, which makes the results dubious.

The Effect of Cadmium on Sleep Parameters Assessed in Polysomnographic Studies: A Case-Control Study

Cadmium is a heavy metal that accumulates in the body due to environmental and occupational exposure. The main form of environmental exposure to cadmium is related to cigarette smoking. The primary aim of this study was to evaluate the effect of cadmium on numerous sleep parameters with the use of polysomnography. The secondary aim of this study was to investigate if environmental exposure to cadmium is a risk factor for the intensity of sleep bruxism (SB).

METHODS

A total of 44 adults underwent a full night of polysomnographic examination. The polysomnograms were assessed according to guidelines set out by the American Academy of Sleep Medicine (AASM). The concentration of cadmium in the blood and urine was determined spectrophotometrically.

RESULTS

The polysomnographic examination confirmed that cadmium, age, male gender and smoking status are independent risk factors for an increase in the apnea-hypopnea index (AHI). Cadmium alters sleep architecture by favoring sleep fragmentation and decreasing the duration of the rapid eye movement (REM) phase of sleep. However, cadmium exposure is not a risk factor for the development of sleep bruxism.

CONCLUSIONS

In summary, this study demonstrates that cadmium affects sleep architecture and is a risk factor for the development of obstructive sleep apnea; however, it does not affect sleep bruxism.

Neuromuscular and occlusion analysis to evaluate the efficacy of three splints on patients with bruxism

OBJECTIVE

Occlusal splints are always applied on individuals with bruxism to reduce tooth wear and relieve orofacial symptoms such as myofascial pain. The stomatognathic system is mainly composed of tooth, occlusion, masticatory muscles, and temporomandibular joint. The occlusion and masticatory muscles function are regarded as the important parameters for evaluating the stomatognathic system state objectively. However, the effects of occlusal splints on individuals with bruxism is rarely elucidated from accurate neuromuscular analysis and occlusion evaluation. The aim of the present study was to estimate the effects of three different splints (two clinically common full coverage occlusal splint and an modified anterior splint) on subjects with bruxism using K7-J5 neuromuscular analysis system and Dental Prescale II (DP2) to evaluate occlusion.

METHODS

Sixteen subjects claimed to be suffering from nocturnal bruxism,with complete dentition and stable occlusal relationship, were selected for study.The intermaxillary space and the baselines of EMG-activity of the anterior temporalis and masseter were recorded for all the subjects. The participants was treated with three different splints, and outcomes were estimated by comfort index, occlusion and surface electromyography of anterior temporalis and masseter.

RESULTS

At teeth clenched position, EMG data were significantly lower in the participants with use of modified anterior splint than with hard, soft occlusal splint or without splint (p < 0.05). The maximum bite force and bite area occur in subjects without use of splint, while the minimal occur in subjects with use of modified anterior splint. Intermaxillary space increased and masticatory muscles presented significant reduction of EMG data at rest position as a result of J5 (p < 0.05).

CONCLUSION

Modified anterior splint seems to be more comfortable and effective in reducing occlusion force and electromyographic activity of anterior temporalis and masseter for subjects with bruxism.

Effects on general pain perception and dental pulp sensibility in probable sleep bruxism subjects by experimentally induced pain in a pilot study

In this pilot study, the general pain perception and the dental pulp sensibility of probable sleep bruxism (SB) subjects were compared with that of non-SB subjects. The cold pressor test (CPT), electric pulp test (EPT), and thermal pulp test with CO₂ snow were executed by one trained dentist (blind to SB diagnosis). A one-factorial multivariate analysis of variance (MANOVA) with SB diagnosis as independent variable and standardized measures regarding pain perception and evaluation was performed. One-hundred-and-five participants (53 SB and 52 non-SB subjects) were included. The one-factorial MANOVA revealed a significant difference between SB and non-SB subjects (p = 0.01) concerning pain perception variables. Post-hoc univariate analyses of variance (ANOVA) showed statistically significant lower general pain tolerance (p = 0.02), higher general subjective sensibility of the teeth (p < 0.01), and a statistical trend for higher subjective dental pain intensity (p = 0.07) in SB subjects. In most of the standardized variables, probable SB subjects seem to react and feel similar to non-SB subjects. However, as probable SB subjects subjectively perceive their teeth to be more sensitive and tend to rate their subjective dental pain intensity more intensely after CO₂ testing, data might point to a somatosensory amplification.