Effect of occlusal equilibration on masticatory muscle activity in females with sleep bruxism: a double-blind randomised controlled trial

Masticatory muscle activity during sleep has been considered independent of variations in the structural characteristics of the dental occlusion. However, scientific evidence contradicting an occlusal causal role is missing. The purpose of this study was to test the null hypothesis that sleep bruxism (SB) is independent of the presence of occlusal interferences. A total of 17 healthy female subjects (mean [SD] age 24.9 [4.1] years) presenting with SB, and randomly divided into two groups, were evaluated after receiving either elimination of occlusal interferences (Test group) or elimination of sharp margins without change in occlusal contacts (Control group). Audio-video polysomnography (PSG) recordings were undertaken before and after treatment (mean [SD] duration 14.4 [3.8] months). Two subjects in each group (< 2 rhythmic masticatory muscle activity [RMMA]/h) were excluded for statistical analysis. During the total sleep time (TST), the Test group exhibited a higher reduction in frequency of episodes per hour than the Control group (p < 0.05). The reduction in duration of episodes was also higher in the Test group during the TST. The Test group presented an increase in sleep stage N3 (p < 0.05) at the final PSG when compared with the initial PSG, and a higher percentage of N3 (p < 0.05) at the final PSG when compared to the Control group. Elimination of occlusal interferences resulted in a significant reduction of masseter and temporal muscle activity during sleep in females presenting with SB. Based on these results, the null hypothesis is rejected. The hypothesis of occlusal interferences as a risk factor for SB is still patent.

Sleep bruxism is highly prevalent in adults with obstructive sleep apnea: a large-scale polysomnographic study

STUDY OBJECTIVES

The aim was to determine the prevalence and risk factors of sleep bruxism (SB) and to investigate the relationships between SB episodes, arousals, and respiratory events in adults with obstructive sleep apnea (OSA).

METHODS

This prospective study included 914 adults with OSA (305 females, 609 males; age = 53 years [interquartile range = 17]; apnea-hypopnea index = 13.9 events/h [interquartile range = 21]). The diagnosis of SB was made when the rhythmic masticatory muscle activity (RMMA) index was at least 2 episodes/h of sleep based on a full polysomnographic recording. Binary logistic regression was performed to identify risk factors for SB. Network analysis was performed to determine the relations between RMMA, respiratory event, sleep arousal, and other factors. Further, the percentage of RMMA time-related to arousal was calculated.

RESULTS

The prevalence of SB in adults with OSA was 49.7%. Male sex, lower body mass index, and higher percentage of N1 sleep increased the odds of having SB (odds ratios = 1.425, 0.951, and 1.032, respectively; all P < .05). Network analysis showed that there were no direct associations between RMMA and apnea-hypopnea index, nor between RMMA and arousal, although 85.7% of RMMA was time-related to arousals.

CONCLUSIONS

Nearly half of adults with OSA have comorbid SB. Male sex, lower body mass index, and a higher percentage of light sleep increase the risk of having SB. Although RMMAs do not directly correlate with respiratory events and arousals, most RMMAs are time-related to arousals in adults with OSA.

CLINICAL TRIAL REGISTRATION

Registry: Netherlands Trial Register; Name: A Large Sample Polysomnographic Study on Sleep Bruxism; URL: https://trialsearch.who.int/Trial2.aspx?TrialID=NL8516; Identifier: NL8516.

CITATION

Li D, Kuang B, Lobbezoo F, de Vries N, Hilgevoord A, Aarab G. Sleep bruxism is highly prevalent in adults with obstructive sleep apnea: a large-scale polysomnographic study. J Clin Sleep Med. 2023;19(3):443-451.

The effects of mandibular advancement appliance therapy on jaw-closing muscle activity time-related to oxygen desaturations: A randomised controlled trial

BACKGROUND

Previous study showed that in individuals with obstructive sleep apnea (OSA), the contractions of masseter muscles after respiratory events can be nonspecific motor phenomena, dependent on the duration of respiratory arousals rather than the occurrence of the respiratory events. However, the role of intermittent hypoxia in the occurrence of jaw-closing muscle activities (JCMAs) was not taken into consideration. An exposure to intermittent hypoxia has been shown to initiate a series of activities, including muscular sympathetic activity in patients with OSA.

OBJECTIVE

To determine the effects of mandibular advancement appliance (MAA) therapy on JCMA time-related to oxygen desaturation with and without arousal in individuals with OSA.

METHODS

Eighteen individuals with OSA (age: 49.4 ± 9.8 years, apnea-hypopnea index (AHI): 10.0|18.4|30.3, JCMA index: 1.7|4.3|5.6), participated in a randomised controlled crossover clinical trial, in which two ambulatory polysomnographic recordings were performed: one with MAA in situ and the other without MAA in situ. JCMAs were recorded bilaterally from both masseter and temporalis muscles.

RESULTS

There was no significant effect of the MAA on the overall JCMA index (Z = -1.372, p = .170). With the MAA in situ, JCMA index time-related to oxygen desaturation with arousal significantly decreased (Z = -2.657, p = .008), while there was no significant effect of the MAA on the JCMA index time-related to oxygen desaturation without arousal (Z = -0.680, p = .496).

CONCLUSION

Effective mandibular advancement appliance therapy significantly reduces jaw-closing muscle activities time-related to oxygen desaturation with arousal in individuals with OSA.

Three-dimensional evaluation of sleep bruxism-related splint wear using a dental laboratory scanner: A preliminary clinical study

BACKGROUND

The wear depth on the occlusal splint (OS) is reportedly associated with the sleep bruxism (SB) level, as evaluated using portable polysomnography (PSG) recordings. However, the OS is deformed owing to SB forces, possibly preventing the accurate quantification of the wear facets.

OBJECTIVES

We aimed to introduce a newly developed system to quantify the wear facets on the OS using a dental laboratory scanner (D810) and investigate the association between the wear facets, as evaluated with this system, and the SB level.

METHODS

Ten healthy individuals who were diagnosed with SB based on portable PSG recordings participated in this study. They were asked to wear the OS for 2 months. The first day after a 2-week adaptation period was defined as the reference day, and sequential scanning of the OS surface was performed on days 15, 30, and 45. Changes in the OS surface from the reference day allowed dimensional evaluation of the wear facets in terms of maximum wear depth, wear area, and wear volume. Multiple regression analyses were conducted to test whether each of these variables could be predicted by any of the SB-related variables.

RESULTS

The total duration of SB episodes per hour of sleep and the maximum muscle activity were significantly associated with the wear area, as measured with our system (adjusted R-squared was .78, p < .01).

CONCLUSION

Our system allows dimensional analysis of the wear facets on the OS surface in association with the SB level.

Diagnostic accuracy of ambulatory polysomnography with electroencephalogram for detection of sleep bruxism-related masticatory muscle activity

STUDY OBJECTIVES

This study investigated the diagnostic accuracy of Sleep Profiler, which relies on ambulatory polysomnography (PSG) with electroencephalogram for sleep bruxism (SB) and examined its episode-by-episode agreement in comparison to PSG equipped with audiovisual recordings (avPSG).

METHODS

This prospective 2-gate study recruited 10 individuals with probable SB and 10 healthy volunteers. Overnight experimental recordings were performed simultaneously using the ambulatory PSG with masseter electromyography and avPSG with masseter and temporalis electromyography. Sleep staging was performed manually for avPSG and automatically or manually for ambulatory PSG. SB episodes were manually scored based on electromyography signals with reference to sleep stages. The episode-by-episode agreement was analyzed by setting avPSG as the reference standard. The sensitivity, specificity, and accuracy for the diagnosis of SB were calculated after optimizing the cutoff values of the episode index and the burst index.

RESULTS

Regarding the episode-by-episode agreement, median sensitivities were 0.825 and positive predictive values were approximately 0.6, regardless of the sleep staging procedure, indicating that approximately 40% of the overall total SB episodes scored by the ambulatory PSG were false positives. Because of overestimation of SB episodes, the optimal cutoff values for the episode index and the burst index were approximately 1.5 times higher than the avPSG-based cutoff values and dramatically improved the diagnostic precision metrics for the ambulatory PSG.

CONCLUSIONS

Sleep Profiler can eliminate events during wakefulness by electroencephalogram and may provide a definitive diagnosis in patients with possible SB by applying optimized cutoff values. However, the risk of overestimation must be recognized.

CLINICAL TRIAL REGISTRATION

Registry: UMIN Clinical Trials Registry; Name: Accuracy of Portable PSG Device for Detection of Sleep Bruxism-Related Masseter EMG Muscle Activity; URL: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037380; Identifier: UMIN000032793.

CITATION

Abe Y, Nakazato Y, Takaba M, Kawana F, Baba K, Kato T. Diagnostic accuracy of ambulatory polysomnography with electroencephalogram for detection of sleep bruxism-related masticatory muscle activity. J Clin Sleep Med. 2023;19(2):379-392.

Associations between snoring and dental sleep conditions: A systematic review

BACKGROUND

It is important for dentists to know if the presence of snoring is associated with the presence of other dental sleep conditions (e.g. obstructive sleep apnea [OSA], sleep bruxism [SB], gastroesophageal reflux disease [GERD], xerostomia and oro-facial pain). If so, dentists could play a significant role in the early recognition and management of these conditions.

OBJECTIVES

This systematic review aimed to: (i) investigate the associations between the presence of snoring and the presence of other dental sleep conditions; and (ii) determine if it is clinically relevant that dentists assess snoring in their population.

METHODS

The literature search was performed in PubMed and Embase.com in collaboration with a medical librarian. Studies were eligible if they employed regression models to assess whether snoring was associated with other dental sleep conditions, and/or investigated the incidence of snoring in patients with other dental sleep conditions and vice versa.

RESULTS

Of the 5299 retrieved references, 36 eligible studies were included. The available evidence indicates that the presence of snoring is associated with higher probabilities of OSA, GERD and headache. Due to limited evidence and conflicting findings, the currently available articles are not indicative of associations between the presence of snoring and the presence of SB and oral dryness.

CONCLUSION

Within the limitations of this study, it can be concluded that the presence of snoring is associated with higher probabilities of OSA, GERD and headache. Therefore, it is clinically relevant that dentists assess snoring in their patient population.

Sleep Apnea-Hypopnea Syndrome and Sleep Bruxism: A Systematic Review

The aim of this study was o determine the relationship between sleep bruxism (SB) and sleep apnea-hypopnea syndrome (SAHS) at the pathophysiological level, the risk factors, as well as the common signs and symptoms. A search was carried out using the databases PubMed, Web of Science, Scopus, and the Cochrane Library together with the Boolean equation "bruxism" AND "sleep apnea" AND "relation*"; the systematic search strategy limited the results to English language articles published from 2013 until December 2021. This review was conducted in accordance with the PRISMA statement. Nine articles were reviewed to relate SAHS and SB at different levels: two were systematic reviews (22%) and seven were research studies (78%). According to the literature reviewed, SB and SAHS occur simultaneously in 21.0% to 41.3% of cases. There are signs and symptoms that are common to both SAHS and SB. Rhythmic masticatory muscle activity (RMMA) precedes an SAHS event in 25% of subjects with SB, in contrast to 55% of the general population. SB and SAHS seem to have a certain concomitance, ranging between 20% and 40%, and they also share some risk factors such as advanced age, obesity, smoking, and alcohol consumption. Dentists should be aware of this relationship, as part of a multidisciplinary team, for early diagnosis.

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.

Relationships between respiratory and oromotor events differ between motor phenotypes in patients with obstructive sleep apnea

Purpose

The present study investigated the relationship between sleep bruxism (SB) and obstructive sleep apnea (OSA) in relation to the sleep architecture.

Methods

We conducted a cross-sectional study. Polysomnographic recordings were performed on 36 patients. Sleep, respiratory, and oromotor variables, such as rhythmic masticatory muscle activity (RMMA) and non-specific masticatory muscle activity (NSMA), were compared between OSA patients with or without SB. A correlation analysis of the frequency of respiratory and oromotor events in NREM and REM sleep was performed. The frequency of oromotor events following respiratory events was also assessed.

Results

The proportion of REM sleep was higher in OSA patients with SB than in those without SB (p = 0.02). The apnea-hypopnea index (AHI) did not significantly differ between the two groups; however, AHI was approximately 8-fold lower during REM sleep in OSA patients with SB (p = 0.01) and the arousal threshold was also lower (p = 0.04). Although the RMMA index was higher in OSA patients with than in those without SB (p < 0.01), the NSMA index did not significantly differ. The percentage of RMMA following respiratory events was significantly higher in OSA patients with than in those without SB, whereas that of NSMA did not significantly differ. The frequency of oromotor events throughout the whole night positively correlated with AHI. However, regardless of the sleep state, AHI did not correlate with the RMMA index, but positively correlated with the NSMA index.

Conclusion

In consideration of the limitations of the present study, the results obtained indicate that OSA patients with SB have a unique phenotype of OSA and also emphasize the distinct relationship of respiratory events with RMMA and NSMA.

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.

ACTN3 genotype influences masseter muscle characteristics and self-reported bruxism

OBJECTIVES

Main aim of the study was to explore the association between genetic polymorphisms in ACTN3 and bruxism. Secondary objectives included masseter muscle phenotypes assessment between bruxers and non-bruxers and according to genetic polymorphisms in ACTN3.

MATERIALS AND METHODS

Fifty-four patients undergoing orthognathic surgery for correction of their malocclusion were enrolled. Self-reported bruxism and temporomandibular disorders status were preoperatively recorded. Saliva samples were used for ACTN3 genotyping. Masseter muscle samples were collected bilaterally at the time of orthognathic surgery to explore the muscle fiber characteristics.

RESULTS

There were significant differences in genotypes for rs1815739 (R577X nonsense) (p = 0.001), rs1671064 (Q523R missense) (p = 0.005), and rs678397 (intronic variant) (p = 0.001) between bruxers and non-bruxers. Patients with self-reported bruxism presented a larger mean fiber area for types IIA (p = 0.035). The mean fiber areas in individuals with the wild-type CC genotype for rs1815739 (R577X) were significantly larger for type IIA fibers (1394.33 μm² [572.77 μm² ]) than in those with the TC and TT genotypes (832.61 μm² [602.43 μm² ] and 526.58 μm² [432.21 μm² ] [p = 0.014]). Similar results for Q523R missense and intronic variants.

CONCLUSIONS

ACTN3 genotypes influence self-reported bruxism in patients with dentofacial deformity through specific masseter muscle fiber characteristics.

Electromyographic Assessment of Masseter Muscle Activity: A Proposal for a 24 h Recording Device with Preliminary Data

OBJECTIVE

The instrumental measurement of electromyographic (EMG) activity in the natural environment is the best strategy available to collect information on bruxism. The twofold aim of this study was to (1) introduce and discuss a novel EMG device for the assessment of awake (AB) and sleep bruxism (SB) in the home environment over 24 h and (2) present some preliminary data.

METHODS

Fifteen healthy volunteers (eight males and seven females; mean age: 48.2 ± 4.1 years) underwent 24 h EMG recording trials of their masseter muscle activity (MMA) with a miniaturized wireless device. This device allowed us to measure the durations of the different phases of the recordings (total duration, awake time, sleep time, and electrode dislodgement time) as well as the bruxism time index (BTI) and bruxism work index (BWI) for both the waking and sleeping hours.

RESULTS

For the healthy volunteers, on average, the bruxism work index (BWI) values were 0.4 ± 0.2 and 0.1 ± 0.1 for awake and sleep, respectively, while the mean bruxism time index (BTI) values were 0.9 ± 0.5 for awake and 0.3 ± 0.1 for sleep.

CONCLUSIONS

This investigation describes the technical features of a novel EMG recording device that permits the evaluation of masseter muscle activity in the home environment over 24 h. For the first time, a dedicated elaboration of the EMG signal allowed an assessment of muscle work and not just a count of purported SB/EMG events.

CLINICAL SIGNIFICANCE

Based on the multidisciplinary approach in the study of bruxism, such a methodology, thanks to its peculiar features, will allow researchers and clinicians to monitor the epidemiology of MMA and delve deeper into the awake and sleep bruxism correlates for tailored management in clinical settings.

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

Background: Sleep bruxism (SB) is a common sleep-related movement behavior with a complex etiology. A recent hypothesis suggests psychoactive substance usage, tobacco smoking, and alcohol intake are risk factors for SB. This study aimed to evaluate SB intensity in tobacco smokers and alcohol drinkers. Methods: A total of 133 adults underwent full-night audio- and video-polysomnography, and the polysomnograms were evaluated using the American Academy of Sleep Medicine guidelines. The study group was divided into smoker and nonsmoker groups as well as drinker and non-drinker groups. Results: The results of the polysomnographic analysis confirmed that tobacco smoking has a significant effects on SB. Tobacco smokers showed increased bruxism intensity (5.50 ± 4.71 vs. 3.83 ± 3.26, p < 0.05), especially the mixed phenotype (0.93 ± 1.00 vs. 0.59 ± 0.59, p < 0.05), in the N1 sleep stage (22.84 ± 20.45 vs. 15.66 ± 13.60, p < 0.05) and the nonsupine position (4.93 ± 5.56 vs. 2.50 ± 2.31, p < 0.05). They also showed a higher number of bruxism episodes with arousal compared with nonsmokers (2.91 ± 2.83 vs. 1.61 ± 1.49, p < 0.05), indicating increased sleep fragmentation. However, no significant effect of alcohol on SB intensity was observed, and the bruxism episode index was similar in alcohol drinkers and nondrinkers. In addition, electrolyte disturbances and lipid disorders were evaluated. Compared with nonsmokers, tobacco smokers showed a higher concentration of plasma triglycerides (177.67 ± 106.9 vs. 129.18 ± 65.61) and lower levels of iron and magnesium (96.68 ± 43.58 vs. 123.83 ± 52.36 and 1.85 ± 0.22 vs. 1.96 ± 0.21, respectively). Conclusions: In summary, this study showed that tobacco smoking, but not alcohol consumption, is related to bruxism intensity and lipid and electrolyte disturbances in individuals with sleep disorders.

The Relationship between the Plasma Concentration of Electrolytes and Intensity of Sleep Bruxism and Blood Pressure Variability among Sleep Bruxers

Plasma sodium plays a major role in regulating blood pressure (BP). An augmented variability of BP is considered a risk factor for the development of arterial hypertension, which is prevalent among patients with suspected sleep bruxism (SB). The aims of this study were to assess the plasma concentration of electrolytes and their effect on the intensity of SB and BP variability among sleep bruxers. A total of 51 patients were enrolled in this prospective, observational study. A single full-night polysomnographic examination was conducted in the Wroclaw Medical University Sleep Laboratory, Poland, and based on the guidelines of the American Academy of Sleep Medicine, the results were analyzed. The monitoring of ambulatory BP was performed the next day, and the plasma levels of sodium, potassium, magnesium, and calcium were measured. The mean age of the studied group was 33.9 ± 11.2 years, and the mean bruxism episode index (BEI) was 4.94 ± 3.53. The study revealed statistically significant differences in the plasma concentrations of sodium in the SB group. A decreased sodium concentration was observed in the group of mild bruxers (2 ≤ BEI < 4) (139.7 ± 1.4 vs. 142.8 ± 3.2, p = 0.002) and severe bruxers (BEI ≥ 4) (140.5 ± 2.0 vs. 142.8 ± 3.2, p = 0.016) compared to nonbruxers (BEI < 2). A statistically significant positive linear correlation was found between plasma sodium concentration and daytime systolic BP variability (r = 0.32, p < 0.05) as well as between plasma sodium concentration and nighttime diastolic BP variability (r = 0.31, p < 0.05). The preliminary results suggest the probable relationship between the lower plasma concentration of sodium and increased intensity of SB and BP variability among suspected sleep bruxers.

Prevalence of painful temporomandibular disorders, awake bruxism and sleep bruxism among patients with severe post-traumatic stress disorder

BACKGROUND

Post-traumatic stress disorder (PTSD) is associated with painful temporomandibular disorder (TMD) and may be part of the aetiology of awake bruxism (AB) and sleep bruxism (SB). Investigating the associations between PTSD symptoms on the one hand, and painful TMD, AB and SB on the other, can help tailoring treatment to the needs of this patient group.

OBJECTIVES

The aim of this study was to investigate the associations between PTSD symptoms and painful TMD, AB and SB among patients with PTSD, focusing on prevalence, symptom severity and the influence of trauma history on the presence of painful TMD, AB and SB.

METHODS

Individuals (N = 673) attending a specialised PTSD clinic were assessed (pre-treatment) for painful TMD (TMD pain screener), AB and SB (Oral Behaviours Checklist), PTSD symptoms (Clinician-Administered PTSD Scale) and type of traumatic events (Life Events Checklist).

RESULTS

Painful TMD, AB and SB were more prevalent among patients with PTSD (28.4%, 48.3% and 40.1%, respectively) than in the general population (8.0%, 31.0% and 15.3%, respectively; all p's < .001). PTSD symptom severity was found to be significantly, but poorly, associated with the severity of painful TMD (rs  = .126, p = .001), AB (rs  = .155, p < .001) and SB (rs  = .084, p = .029). Patients who had been exposed to sexual assault were more likely to report AB than patients who had not. Similarly, exposure to physical violence was associated with increased odds for SB.

CONCLUSION

Patients with severe PTSD are more likely to experience painful TMD, AB or SB, whereas type of traumatic event can be of influence. These findings can contribute to selecting appropriate treatment modalities when treating patients with painful TMD, AB and SB.

Evaluation of mandibular trabecular bone by fractal analysis on panoramic radiograph in paediatric patients with sleep bruxism

OBJECTIVE

To evaluate the trabecular bone density in the mandible of paediatric patients diagnosed with sleep bruxism (SB) using the fractal analysis method on panoramic radiographs.

METHODS

A total of 37 patients whose anamnesis and clinical signs were compatible with SB were diagnosed with SB using BiteStrip^® . Three areas were identified on the panoramic radiographs of the patients: the geometric center of the condyle, the angulus region under the mandibular canal, and the distal region of the mental foramen. Regions of interest (ROIs) of 60 × 60 pixels were selected in these three locations, and fractal dimensions (FDs) were calculated. Results were compared with the control group.

RESULTS

There was no statistically significant difference between the right and left FD values, and male and female FD values in all regions and both groups (p > .05). In the angulus (p = .03) and condyle (p = .03) regions, the SB group had a significantly higher FD value than the control group. There was no statistically significant difference between the SB and control groups in the corpus region (p = .98). A moderate negative correlation arose between age and condyle FD values among controls (r = -0.38, p = .02).

CONCLUSION

Fractal dimension values evaluating trabeculation of the mandibular bone are affected by SB in the angulus and condyle regions.

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.

Impact of Confinement by COVID-19 in Awake and Sleep Bruxism Reported by Portuguese Dental Students

Confinement by COVID-19 was a stressful period that could potentially trigger awake bruxism (AB) and/or sleep bruxism (SB) behaviors. This study aims to characterize the AB and SB behaviors reported by Portuguese dental students before the pandemic and during the first period of mandatory confinement by COVID-19. Dental students were included in this longitudinal study. They answered the Portuguese validated version of the Oral Behavior Checklist (OBC) before the COVID-19 pandemic emerged (T1) and one month after mandatory confinement started in Portugal (T2). Descriptive statistics and the linear-by-linear association test were performed to assess changes over time (p ≤ 0.05). Sixty-four dental students (mean age 22.5 ± 2.8 years; 81.5% females) completed the study protocol. Considering AB, there was a general increase of the behavior from T1 to T2. The percentage of participants who reported to “grind their teeth when waking up” just few times decreased (p < 0.001) and the percentage of participants who reported “feeling discomfort/tension in the facial muscles when waking up just few times” increased (p = 0.019). Considering SB, there was a significant decrease of the behavior in all samples. The number of “None” report to grinding teeth during sleep or when waking up increased (p = 0.012). An increase in the self-reporting of feeling discomfort in masticatory muscles when awake or sleeping was observed (p = 0.028). The percentage of participants who did “not remember” any AB or SB activity decreased (p < 0.050). The confinement due to COVID-19 resulted in a forced change in dental students’ lifestyles that resulted in an increase of reported AB and a decrease of reported SB. Clinical Significance: In case of confinement periods, students should be encouraged to try normalizing their daily life by creating healthy routines and, by doing so, reducing the possible predisposition to bruxism and its consequences.

Can sleeping habits be associated with sleep bruxism, temporomandibular disorders and dental caries among children?

BACKGROUND

Sleeping problems are common in the pediatric population. Their potential relationship with oral manifestations is in the scope of researchers' interest.

OBJECTIVES

The aim of the present study was to evaluate the possible associations between sleeping habits and sleep bruxism, temporomandibular disorders (TMD) and dental caries among children by using Children's Sleep Habits Questionnaire (CSHQ).

MATERIAL AND METHODS

A cross-sectional study was carried out at the Faculty of Dentistry of Istanbul Aydin University, Turkey, with a representative sample of 100 children aged 6-13 years. The CSHQ was completed by their parents. In addition, an intraoral examination was carried out in a clinical setting and sleep bruxism was recorded. The temporomandibular joints (TMJ) were examined and TMD were rated according to the Helkimo anamnestic and clinical dysfunction index. Data was analyzed with Fisher's exact test and the χ2 test.

RESULTS

Among sleeping habits, bedtime resistance was found to be significantly associated with sleep bruxism and TMD symptoms in children. Sleep behavior problems were also found to be related to TMD. Untreated dental caries was significantly associated with sleep fragmentation.

CONCLUSIONS

Sleep bruxism, TMD and untreated dental caries might have a negative impact on children's sleeping habits and characteristics. Pediatricians and pedodontists should collaborate to identify the causes and clinical features of sleeping habits and disorders in order to avoid adverse effects on the child's stomatognathic system.

Influence of MAD Application on Episodes of Obstructive Apnea and Bruxism during Sleep-A Prospective Study

The condition of sleep bruxism (SB) is defined by many authors as the body's response to obstructive sleep apnea (OSA). In the conservative treatment of OSA, mandibular advancement devices (MADs) have found their application. The aim of the study iso assess the impact of MADs on the occurrence of episodes and the intensity of OSA and SB. The study sample consisted of eight patients with OSA and SB diagnosed with these conditions on the basis of clinical examinations and polysomnography (PSG). The prospective study was designed to assess the use of MADs for OSA and SB. MADs were prepared for the patients who subsequently underwent control examinations after one week of wear, and another PSG (PSG II) with an MAD was performed in conditions resembling the first qualification examination (PSG I). The same parameters were assessed in both PSG examinations. Following treatment with the MAD, a favorable lowering of the mean values of the examined parameters was observed. The statistically significant differences were demonstrated only for the apnea-hypopnea index (AHI), the oxygen desaturation index (ODI), and the number of apneas and hypopneas, obstructive apneas, apneas in OSA, and phasic episodes of bruxism. The application of MADs in patients with OSA has a beneficial effect on the same manifestations of OSA and SB, even though only the number of phasic episodes of bruxism was statistically significant.

Association between the severity of possible sleep bruxism and possible awake bruxism and attrition tooth wear facets in children and adolescents

OBJECTIVE

To evaluate the association between the severity of possible sleep bruxism (PSB) and possible awake bruxism (PAB) and attrition tooth wear facets (ATWF) in children/adolescents.

METHODS

Four hundred-thirty-four children/adolescents enrolled in schools in Lavras, Brazil, participated in this cross-sectional study. Caregivers answered a questionnaire about their childrens' PSB. Children/adolescents answered a questionnaire about the occurrence of PAB.

RESULTS

ATWF among individuals without PSB and PAB was lower than those with moderate/severe PSB (p = 0.038) and moderate/severe PAB (p = 0.003). ATWF in anterior teeth was lower among individuals without PSB compared to those with mild (p = 0.015) and moderate/severe PSB (p = 0.032). ATWF in posterior teeth was lower among individuals without PAB compared to those with mild (p = 0.046) and moderate/severe PAB (p = 0.017).

CONCLUSION

The number of attrition tooth wear facets is proportional to the severity of PSB and PAB.

Incidence of Sleep Bruxism in Different Phenotypes of Obstructive Sleep Apnea

(1) Background: Sleep bruxism (SB) is a common sleep behavior. Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder with potential long-term major neurocognitive and cardiovascular sequelae. Although the co-occurrence of SB and OSA has been described previously, the exact relationship remains unclear. The present study aimed to evaluate the incidence of SB in different phenotypes of OSA. (2) Methods: The participants of this study were adult patients referred to 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 in a sleep laboratory. The data related to common OSA phenotypes were analyzed in two separate groups of patients: body position related (n = 94) and rapid eye movement (REM) related (n = 85). (3) Results: The obtained results showed that the incidence of SB and severe SB was higher for body position-related OSA phenotype (p < 0.05 for all comparisons). No statistically significant differences were observed for REM-related OSA phenotype (p > 0.05 for all comparisons). (4) Conclusions: Body position-related OSA phenotype seems to be associated with higher SB and severe SB incidence, but the relationship is not independent. However, in the light of the unclear relationship between SB and sleep-disordered breathing, the topic needs further study.

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.

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.

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.