Sleep-related rhythmic movement disorder in adults - A systematic review with a case report.

Sleep-related rhythmic movement disorder is characterised by stereotyped and repetitive rhythmic movements involving large muscle groups during sleep with frequencies between 0.5 and 2 Hz. Most of the published studies on sleep-related rhythmic movement disorder have focussed on children. Therefore, we performed a systematic review on this topic focussing on the adult population. The review is followed by a case report. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. A total of seven manuscripts (n = 32 individuals) were included in the review. The clinical manifestation of body or head rolling predominated in the majority of included cases (53.13% and 43.75%, respectively). In n = 11 (34.37%) cases, a combination of rhythmic movements was observed. The literature review also revealed a wide spectrum of co-morbidities: insomnia, restless leg syndrome, obstructive sleep apnea, ischaemic stroke, epilepsy, hypertension, alcohol and drug dependency, mild depression, and diabetes mellitus. The case report presented a 33-year-old female who was referred to the sleep laboratory due to a suspicion of sleep bruxism and obstructive sleep apnea. Although the patient was initially suspected of having obstructive sleep apnea and sleep bruxism, after conducting video-polysomnography she met the criteria for sleep-related rhythmic movement disorder as she presented body rolling, which were surprisingly most evident during the rapid eye movement sleep stage. In summary, the prevalence of sleep-related rhythmic movement disorder among adults has not been determined yet. The present review and case report is a good starting point for discussion regarding rhythmic movement disorder in adults and further research on this topic.

Is camera recording crucial for the correct diagnosis of sleep bruxism in polysomnography?

Due to potential issues, several sleep laboratories conduct sleep bruxism diagnosis without the use of a camera, instead relying mostly on electromyographic monitoring. The purpose of the study was to determine if a camera is necessary for the polysomnographic evaluation of sleep bruxism and how sleep bruxism parameters change when a camera is not utilised. The study material was actual polysomnographic recordings made in the years 2017-2020. A total of 199 single-night video-polysomnographic recordings of patients who were suspected of having sleep bruxism were chosen at random. The first analysis involved the evaluation of the video recording, while in the second video recording was not used. The findings revealed that all the examined sleep bruxism indices had statistically significantly higher values for the recordings made without the use of a camera. According to the findings, noncamera recordings had decreased sensitivity and specificity when the criteria of bruxism and mild-to-moderate bruxism were taken into account, and decreased sensitivity in the case of the criterion of severe bruxism. Sleep efficiency, the apnea/hypopnea index, and arousals had independent effects on the bruxism episode index value in the analysis of noncamera recordings. In conclusion, camera-based polysomnography still appears to be the most reliable way to assess the severity of sleep bruxism, particularly in patients who also report other sleep disturbances. The presence of symptoms of sleep-disordered breathing, insomnia, or other sleep disorders should prompt us to use camera-based diagnostics.

Is sleep bruxism related to the levels of enzymes involved in the serotonin synthesis pathway?

OBJECTIVES: This exploratory research aimed to evaluate the levels of tryptophan hydroxylase 1 (TPH1) and aromatic l-amino acid decarboxylase (DDC), which play an important role in the serotonin synthesis pathway, in individuals with sleep bruxism (SB) diagnosed using audio-video polysomnography (vPSG) and compare them with that of individuals not presenting with SB. MATERIALS AND METHODS: The study included adult patients hospitalized in the Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology at the Wroclaw Medical University. The participants underwent a single-night vPSG for the evaluation of the SB parameters. Peripheral blood samples were also collected from them for estimating the serum levels of TPH1 and DDC. RESULTS: A total of 105 patients (80 women and 25 men) were included in the study. All the patients were Caucasians and aged 18-63 years (mean age: 33.43 ± 10.8 years). Seventy-five patients (71.43%) presented with SB, of which 50 (47.62%) had severe SB, while the remaining 30 patients (28.57%) did not. No statistically significant differences in TPH1 and DDC levels were observed between the individuals with SB and without SB. A significant negative correlation was found between tonic SB episodes and DDC levels (p = 0.0012). Other correlations between the SB parameters and the levels of the studied enzymes were statistically insignificant (p > 0.05 for all comparisons). CONCLUSIONS: The levels of the enzymes that are crucial for serotonin synthesis (TPH1 and DDC) did not seem to influence SB. CLINICAL RELEVANCE: This study provides important insights for further research on the relationship between the serotonin pathway and SB, which should take into account not only the process of serotonin synthesis but also the effect of serotonin-dependent neurotransmission on SB.

Lower serotonin levels in severe sleep bruxism and its association with sleep, heart rate, and body mass index.

BACKGROUND: Sleep bruxism (SB) is a complex behaviour that seems to be associated with the serotoninergic pathway. OBJECTIVES: This exploratory research aimed to evaluate the levels of serotonin in individuals with sleep bruxism diagnosed by video polysomnography. The study also evaluated whether the levels of serotonin were associated with body mass index, heart rate, and sleep parameters. METHODS: The study participants were adults hospitalised in the Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology at the Wroclaw Medical University. They underwent a single-night video polysomnography during which sleep and SB parameters and heart rate were evaluated. Additionally, body mass index and blood serotonin levels were evaluated for each patient. RESULTS: A total of 105 patients were included in this study (80 women and 25 men). All the patients were Caucasians aged 18-63 years, with a mean age ± (standard deviation) of 33.43± 10.8 years. Seventy-five patients (71.43%) presented sleep bruxism (bruxism episodes index ≥2) and 30 (28.57%) did not. Fifty patients (47.62%) presented severe sleep bruxism (bruxism episodes index >4). The results showed that lower blood serotonin levels were associated with severe sleep bruxism; increased bruxism episodes index, rapid eye movement sleep, and body mass index; and decreased maximal pulse. CONCLUSION: Severe sleep bruxism and the associated phenomena seem to co-occur with lower blood serotonin levels. The study supports the hypothesis on the relationship between the serotoninergic pathway and sleep bruxism.

The effect of continuous positive airway pressure and mandibular advancement device on sleep bruxism intensity in obstructive sleep apnea patients.

We aimed to evaluate and compare the effects of continuous positive airway pressure (CPAP) and mandibular advancement device (MAD) in reducing the intensity of sleep bruxism (SB) in patients with obstructive sleep apnea (OSA). Forty-eight adults with OSA were subjected to single-night full polysomnography (PSG) in the Sleep Laboratory of the Wroclaw Medical University. The respiratory events and bruxism episodes were scored according to the standards of the American Academy of Sleep Medicine. The patients were assigned to the CPAP treatment or the MAD treatment in accordance to apnea-hypopnea index (AHI). The second PSG examination was conducted during the MAD or CPAP treatment to assess the effect of treatment on bruxism episode index (BEI) and AHI. The mean AHI and mean BEI in the study material were estimated to be 30.05 ± 15.39 and 5.10 ± 5.31, respectively. The bruxism parameters were significantly decreased in both the CPAP and MAD groups. Compared to the MAD, the CPAP treatment was more effective in reducing AHI; however, there was no significant difference in effectiveness of CPAP and MAD treatment in BEI reduction. Both CPAP and MAD treatments were effective against SB coexisting with OSA. Due to the application of these treatment options, the risk of OSA should be estimated in patients with SB.

Influence of age and gender on sleep bruxism and snoring in non-apneic snoring patients: A polysomnographic study.

The present study aimed to assess the influence of gender and age on snoring and sleep bruxism in non-apneic snoring patients. Adult participants with clinical suspicion of snoring and with no other significant medical history were recruited. Single-night video polysomnography was performed to detect snoring and sleep bruxism. Finally, 137 snoring non-apneic participants were included. Statistical analysis of gender groups showed that the total snore index and snore train were significantly higher in men than in women. Men also presented severe bruxism, with significantly more frequent episodes and higher bruxism episodes index scores. The correlation analysis showed the presence of significant linear relationships in the supine sleep position between age and snore index, snore index in non-rapid eye movement 2 (N2) sleep stage, and snore train. The analysis of groups separated according to the criterion of third age quartile showed that the average, maximum and minimum audio volume in the non-supine sleep position was significantly higher in the older group. The analysis of groups separated according to the criterion of median age showed that the bruxism episode index and bruxism phasic episodes were significantly higher in the younger group. Thus, it can be concluded that both age and gender influence snoring and sleep bruxism. Snoring and sleep bruxism seem to be more intensive in men. Older patients seem to snore more in N2 sleep and the supine sleep position and present lower bruxism episodes, especially the phasic type. The results of the present study indicate the need for further research on this topic to establish the possible relationship between snoring and sleep bruxism.

Sleep structure in sleep bruxism: A polysomnographic study including bruxism activity phenotypes across sleep stages.

The aim of the study was to assess sleep structure, phenotypes related to bruxism activity and basic respiratory parameters among a large group of participants with sleep bruxism and without obstructive sleep apnea. Adult participants with clinical suspicion of sleep bruxism and with no other significant medical history were recruited. Video-polysomnography was performed to detect masseter muscles activity. Polysomnographic scoring was performed according to the American Academy of Sleep Medicine Criteria. Finally, 146 participants were included. The participants were divided into three subgroups: severe, mild and no sleep bruxism. There were no differences in total sleep time, sleep latency, sleep efficiency, wake duration after sleep onset, rapid eye movement, and measured respiratory parameters. The severity of sleep bruxism contributed to the increased intensity of all sleep bruxism phenotypes in almost all sleep stages, apart from tonic and mixed activity in non-rapid eye movement stage 3 sleep (slow-wave sleep). Those with bruxism spent more time in rapid eye movement sleep compared to controls; there were no differences in non-rapid eye movement sleep stages. The results confirmed that sleep bruxism does not significantly affect sleep duration, efficiency and continuity (in terms of sleep-wake cycles). Sleep bruxism contributes to a higher percentage of rapid eye movement sleep in the total sleep time. Those with bruxism present more frequent episodes during all stages of sleep; however, in the case of slow-wave sleep, tonic and mixed activity observed in participants with sleep bruxism are comparable to those of healthy people.

Distribution of temporomandibular disorders among sleep bruxers and non-bruxers-A polysomnographic study.

INTRODUCTION: Bruxism is often indicated as a risk factor for the occurrence of temporomandibular disorders (TMD). Despite the frequent co-occurrence of bruxism and TMD, the exact relationship between these phenomena has not been thoroughly explained, and their causal relationship is still considered controversial. AIM: The aim of this study was to evaluate the distribution of TMD among sleep bruxers and non-bruxers. MATERIALS AND METHODS: The participants of this study were 77 patients of the Clinic of Prosthetic Dentistry operating at the Department of Prosthetic Dentistry, Wroclaw Medical University who had been diagnosed with TMD and probable sleep bruxism. Patients underwent video-polysomnography to assess the intensity of sleep bruxism using the Bruxism Episode Index (BEI). RESULTS: The following TMD diagnoses were made: local myalgia, temporal tendonitis, myofascial pain, myofascial pain with referral, hypertrophy, osteoarthrosis, disc displacement with reduction, disc displacement without reduction with limited opening, subluxation, adhesions/adherence, arthralgia, headache attributed to TMD and oromandibular dystonia. None of these occurred statistically significantly more often in the studied group (bruxers; BEI ≥ 2) than in the control group (non-bruxers; BEI < 2); (P > .05 for all comparisons). CONCLUSION: The distribution of TMD among sleep bruxers and non-bruxers is similar. Therefore, the prevalence of sleep bruxism seems not to be a certain risk factor for TMD occurrence.

Decrypting the putative interrelation between sleep bruxism, masticatory muscle pain and sleep breathing disorders: Nosology and the role of hypoxia.

This commentary on sleep medicine explores whether the potential relationship between sleep bruxism (SB), masticatory muscle pain (MMP) and sleep breathing disorders (SBDs)contributes to improving the management of co-occurring conditions.The paper is divided into 2 sections: (1) reviewing the debate on SB nosology; and (2) based on the publications from the Martynowicz & Wieckiewicz research group, exploringthe role of intermittent hypoxia as a putative mechanism endotype that may link such co-occurrence among individuals for whom characteristics are not yet clear.

Journal Impact Factor and highly cited papers: The beginning of a new era in Dental and Medical Problems.

We are delighted to announce that Dental and Medical Problems is the first dentistry-focused scholarly journal in Poland and Eastern Europe to achieve a Journal Impact Factor (JIF) in the latest 2023 release of the Journal Citation Reports™!

Polysomnography findings in sleep-related eating disorder: a systematic review and case report.

Background: Sleep-related eating disorder (SRED) consists of recurrent episodes of uncontrolled, involuntary eating and drinking 1-3 h after falling asleep with partial or full unconsciousness. This condition is diagnosed based on interviews with the patients affected and the diagnostic criteria of the International Classification of Sleep Disorders. However, polysomnography (PSG) is not necessary to confirm this disease. This systematic review aims to evaluate the findings of PSG in SRED patients. Methods: For this systematic review, PubMed, Embase, and Scopus databases were searched in February 2023, which resulted in 219 records. After removing duplicates, the articles that included the presentation of PSG results of SRED patients in English were selected. In addition, only original studies were considered. The risk of bias by using case reports and descriptive studies was assessed using the Joanna Briggs Institute critical appraisal tools and the Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool. Furthermore, a case report of a 66-year-old woman with SRED was included. Results: A total of 15 papers were selected for further analysis, of which 7 were descriptive studies, 6 were case reports, and 2 were observational studies. The risk of bias in the majority of the studies was moderate or high. Unexpectedly, if the eating episode occurred during PSG, in most cases it was not observed during deep sleep (the N3 sleep stage). Moreover, studies did not report significant deviations in the sleep parameters measured using PSG. Among SRED patients, the prevalence of sleepwalking was much higher than the general population. Our case report presented a potentially life-threatening episode of holding an apple in the mouth that might result in choking, which was captured using PSG. Conclusion: Polysomnography is not necessary for the diagnosis of SRED. However, it could facilitate the diagnosis and differentiation of SRED from other eating disorders. PSG also has limitations in capturing eating episodes and in addition, its cost effectiveness should be considered during the diagnostic process. More studies into the pathophysiology of SRED are needed because classifying SRED as non-rapid eye movement parasomnias can be inappropriate as it does not always occur during deep sleep.

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.

Polysomnographic Evaluation of Sleep Bruxism Intensity and Sleep Architecture in Nonapneic Hypertensives: A Prospective, Observational Study.

Sleep bruxism (SB) is a repetitive jaw muscle activity characterized by clenching or grinding of the teeth, which is classified under sleep-related movement disorders in the International Classification of Sleep Disorders-Third Edition. Because the potential common pathomechanism of SB and arterial hypertension is the activation of the sympathetic system as well as an increase in inflammatory factors, we aimed to examine the intensity of SB and the sleep architecture among patients with arterial hypertension. The study included a total of 91 Caucasian adult patients, among whom 31 had arterial hypertension diagnosed according to the current European Society of Cardiology/European Society of Hypertension (ESC/EHS) hypertension guidelines. The control group consisted of 61 normotensive patients. Patients with obstructive sleep apnea were excluded. A single full-night polysomnographic examination was conducted in the Sleep Laboratory, and then the results were analyzed based on the guidelines of the American Academy of Sleep Medicine. Bruxism episode index (BEI) was higher in the hypertensive group compared to normotensives. The groups also showed statistically significant differences in polysomnographic sleep indexes. Similar to BEI, arousal index, apnea-hypopnea index, and snoring were higher in hypertensives compared to normotensives. On the other hand, the mean and minimal oxygen saturation were lower in hypertensives compared to normotensives. A statistically significant positive correlation was observed between oxygen desaturation index and BEI in the hypertensive group, whereas this correlation was not statistically significant in the case of normotensives. In summary, nonapneic hypertensives had higher SB intensity, altered sleep architecture, decreased mean oxygen saturation, and increased snoring compared to normotensives. The results suggest that dental screening is necessary for patients with arterial hypertension, especially those presenting with the symptoms of SB.

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.

Sleep Bruxism Contributes to Motor Activity Increase during Sleep in Apneic and Nonapneic Patients-A Polysomnographic Study.

BACKGROUND: Jaw motor activity (MA) in sleep bruxism (SB) has been demonstrated to accompany lower limb movements. However, it remains unknown whether SB activity coexists with other types of movements and what the possible underlying mechanisms of such temporal coexistence are. In obstructive sleep apnea (OSA), increased movement activity is also reported, including SB activity; however, no studies have compared MA in apneic and nonapneic SB patients. AIM: This cross-sectional study focused on the phenomenon of "big body movements" in patients with either SB or OSA (or both) and intended to identify the primary factors contributing to their appearance, using polysomnography (PSG) recording. METHODS: A whole-night videoPSG was carried out in 287 participants, and 124 apneic and 146 nonapneic participants were selected for the study. In both groups, participants were further divided into no SB, moderate SB, and severe SB (SSB) subgroups based on their bruxism episode index (BEI). MA was recorded using a built-in sensor of the central PSG unit located on the participant's chest during the examination. RESULTS: The presence of SB was related to the higher intensity of MA in both apneic and nonapneic participants, though in general the MA level was higher in apneic participants, with the highest level observed in SSB apneic participants. CONCLUSIONS: SB might contribute to MA. The prevalence of SB might be higher in nonapneic patients due to phasic and mixed SB activity, whereas the SB phenotype seems to be less relevant in apneic patients. SB activity is likely to increase MA in non-REM 1 sleep.

Identification of risk groups for mental disorders, headache and oral behaviors in adults during the COVID-19 pandemic.

The dramatically changing situation during COVID-19 pandemic, is anticipated to provoke psycho-emotional disturbances and somatization arising from the current epidemiological situation that will become a significant problem for global and regional healthcare systems. The aim of this study was to identify the predictors, risk factors and factors associated with mental disorders, headache and potentially stress-modulated parafunctional oral behaviors among the adult residents of North America and Europe as indirect health effects of the COVID-19 pandemic. This may help limit the long-term effects of this and future global pandemic crises. The data were collected from 1642 respondents using an online survey. The results demonstrated increased levels of anxiety, depression, headache and parafunctional oral behaviors during the COVID-19 pandemic in both North American and European residents. The results of this study facilitated the definition of the group most predicted to experience the aforementioned secondary effects of the pandemic. This group included females younger than 28.5 years old, especially those who were single, less well educated and living in Europe. In case of this and other global crises this will allow faster defining the most vulnerable groups and providing rapid and more targeted intervention.

The Relationship between Simple Snoring and Sleep Bruxism: A Polysomnographic Study.

Simple snoring is defined as the production of sound in the upper aerodigestive tract during sleep, not accompanied by other pathologies. Sleep bruxism (SB) refers to repetitive phasic, tonic, or mixed masticatory muscle activity during sleep. In this study, we investigated the relationship between simple snoring and SB in patients without obstructive sleep apnea (OSA). A total of 565 snoring subjects underwent polysomnography. After examination, individuals with OSA were excluded from the study group. Finally, 129 individuals were analyzed. The bruxism episode index was positively correlated with maximum snore intensity. Phasic bruxism was positively correlated with snore intensity in all sleep positions. Bruxers had a significantly decreased average and minimum heart rate compared with non-bruxers. Supine sleep position seemed to have a significant impact on snore intensity and SB. In summary, our study showed the relationship between SB, snore intensity, and body position. Phasic bruxism was positively correlated with snore intensity despite the body position, which is an interesting and novel finding.

The meaning of the masticatory muscle tonic-type electromyographic pathway correlated with sleep bruxism and sleep-related breathing disorders - A polysomnographic study.

STUDY OBJECTIVES: The coexistence of sleep-related breathing disorders (SRBD) and sleep bruxism (SB) is often mentioned in the literature. Polysomnography (PSG) with video recording gives the best opportunity to identify both of these phenomena. This study aimed to evaluate the relationship between SRBD and SB. METHODS: Patients from the Clinic of Prosthetic Dentistry operating at Wroclaw Medical University with diagnosed probable SB were subjected to one-night video-polysomnography. PSGs were evaluated according to standard sleep criteria. The results of the examination were analyzed for the occurrence of SB and SRBD. The Bruxism Episodes Index (BEI) and the types of electromyographical pathways (phasic, tonic, mixed) were used to evaluate SB. The Apnea/Hypopnea Index (AHI) and Oxygen Desaturation Index (ODI) were used to assess respiratory events. Subjects were divided into two groups according to SB occurrence: the studied group (bruxers, BEI ≥ 2) and control group (non-bruxers, BEI < 2). RESULTS: Quantitative analysis showed a lack of a statistically significant relationship between BEI and AHI (p = 0.82) and ODI (p = 0.90) in the studied group and controls. Qualitative analysis showed that the increase in both AHI and ODI was statistically significantly correlated with the increase in the number of tonic types of electromyographical pathways (p = 0.047, p = 0.006, respectively). CONCLUSIONS: This study showed a significant relationship between tonic electromyographic pathways in SB episodes and SRBD. Tonic muscle contractions can be cause and effect for the formation of respiratory events. The occurrence of tonic episodes may be the key to understanding the causal relationship between SB and SRBD and should be more precisely examined. CLINICAL TRIAL: Evaluation of Selected Disorders with Sleep Bruxism, www.ClinicalTrials.gov, identifier NCT03083405.

Genetic basis of sleep bruxism and sleep apnea-response to a medical puzzle.

Sleep bruxism (SB) and obstructive sleep apnea (OSA) are co-occurring sleep conditions. The study aimed to evaluate the association of selected single-nucleotide polymorphisms (SNPs) occurring within the genes of the serotonin and dopamine pathways in SB and OSA and investigate the relationship between them. The study group included 100 Caucasian patients. SB and OSA were diagnosed in 74 and 28 patients, respectively. In addition, 125 unrelated Caucasian healthy blood donors served as randomly selected controls to enable comparison of polymorphisms. The following SNPs were analyzed: rs2770304 and rs6313 within the serotonin receptor encoding gene (HTR2A), rs4680 polymorphism of the catechol-O-methyltransferase (COMT) gene, and rs686 within the dopamine receptor (DRD1) encoding gene. The prevalence of the DRD1 rs686 G variant (GG homozygosity) was found to be high in the study group compared to the control group. Bruxism episode index (BEI) was found to be significantly increased in the HTR2A rs6313 TT homozygotes compared to the heterozygous patients. Moreover, within a group of the HTR2A rs2770304 TT homozygous cases, a statistically significant correlation was observed between BEI and apnea-hypopnea index. These results indicate that DRD1 rs686 may potentially affect predisposition to SB, that HTR2A rs6313 SNP may be involved in SB pathogenesis, and that HTR2A rs2770304 polymorphism might contribute to the association between SB and OSA. This suggests a possible genetic contribution to the etiology of primary SB.

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.