Sleep bruxism in children and adolescents-A scoping review.

BACKGROUND AND OBJECTIVE: This review paper focuses on sleep bruxism (SB) in children and adolescents. It aims to assess the landscape of knowledge published in the last 20 years. METHODS: A total of 144 relevant publications from 386 previously identified through Medline were included, of which 83 were on possible SB, 37 on probable SB, 20 on definite SB and 4 were non-applicable. The review places emphasis on the recent evidence on prevalence, pathophysiology, diagnosis and management of SB in children and adolescents, with special focus on probable and definitive SB. RESULTS: The prevalence ranges from 5% to 50% depending on the age range and on the SB diagnosis (possible, probable or definitive). The pathophysiology is multifactorial, arousal associated and with behavioural problems and sleep disorders (obstructive sleep apnoea, snoring, nightmares) as risk factors, as well as respiratory conditions (allergies, oral breathing). Screening should include questionnaires and dental assessment. Instrumental recording is helpful to confirm diagnosis although more studies are needed to validate this approach in children. SB management includes controlling orofacial and dental consequences and assessing for any other comorbidity. Management options include occlusal splints, oral appliances (advancement mandibular), rapid maxillary expansion and some medications, although this last option is supported by limited evidences in children. CONCLUSION: Suggestions of future topics in research are delivered to better understand comorbidities, diagnosis and management with improved outcomes compared to what is currently available.

Prevalence, Severity, and Description of Dental Anomalies in Children Treated for Acute Lymphoblastic Leukemia.

Purpose: To assess the prevalence and severity of and describe dental anomalies in children treated for acute lymphoblastic leukemia (ALL) under recent Dana-Farber Cancer Institute (DFCI) protocols. Methods: Patients aged between 14 and 25 years old having received a diag- nosis of ALL before the age of 11 years and after September 2000 received clinical and radiographic oral examinations. Results: Dental anomalies were observed in 26 (51.0 percent) of 51 subjects. Microdontia was the most prevalent dental defect (39.2 percent). Impacted permanent second molars were observed in five (9.8 percent) patients. Being age five years or younger at diagnosis significantly increased the prevalence and severity of dental anomalies (P<0.001). Conclusions: Recent DFCI protocols showed a decreased prevalence of dental disturbances. The anomalies observed may still alter the development of the dental arches and occlusion in pediatric ALL survivors. Further research is needed to confirm the association between ALL treatment and permanent second molar impaction.

Reliability and accuracy of a semi-automatic segmentation protocol of the nasal cavity using cone beam computed tomography in patients with sleep apnea.

OBJECTIVES: The objectives of this study included using the cone beam computed tomography (CBCT) technology to assess: (1) intra- and inter-observer reliability of the volume measurement of the nasal cavity; (2) the accuracy of the segmentation protocol for evaluation of the nasal cavity. MATERIALS AND METHODS: This study used test-retest reliability and accuracy methods within two different population sample groups, from Eastern Asia and North America. Thirty obstructive sleep apnea (OSA) patients were randomly selected from administrative and research oral health data archived at two dental faculties in China and Canada. To assess the reliability of the protocol, two observers performed nasal cavity volume measurement twice with a 10-day interval, using Amira software (v4.1, Visage Imaging Inc., Carlsbad, CA). The accuracy study used a computerized tomography (CT) scan of an OSA patient, who was not included in the study sample, to fabricate an anthropomorphic phantom of the nasal cavity volume with known dimensions (18.9 ml, gold standard). This phantom was scanned using one NewTom 5G (QR systems, Verona, Italy) CBCT scanner. The nasal cavity was segmented based on CBCT images and converted into standard tessellation language (STL) models. The volume of the nasal cavity was measured on the acquired STL models (18.99 ± 0.066 ml). RESULTS: The intra-observer and inter-observer intraclass correlation coefficients for the volume measurement of the nasal cavity were 0.980-0.997 and 0.948-0.992 consecutively. The nasal cavity volume measurement was overestimated by 1.1%-3.1%, compared to the gold standard. CONCLUSIONS: The semi-automatic segmentation protocol of the nasal cavity in patients with sleep apnea and by using cone beam computed tomography is reliable and accurate. CLINICAL RELEVANCE: This study provides a reliable and accurate protocol for segmentation of nasal cavity, which will facilitate the clinician to analyze the images within nasoethmoidal region.

Orthodontic and Facial Characteristics of Craniofacial Syndromic Children with Obstructive Sleep Apnea.

Introduction: Obstructive sleep apnea (OSA) is a disorder in which ventilation becomes disrupted due to a complete or partial upper airway obstruction Altered craniofacial morphology is one of the most important anatomical factors associated with obstructive sleep apnea (OSA). Studies have assessed craniofacial features in the non-syndromic pediatric population. The aim of this study was to analyze the orthodontic and facial characteristic of craniofacial syndromic children referred for polysomnography (PSG) and to assess the correlation with the apnea-hypopnea index (AHI). Methods: In the current cross-sectional study, consecutive syndromic patients referred for PSG were invited to participate. A systematic clinical examination including extra- and intra-oral orthodontic examination was performed by calibrated orthodontists. Standardized frontal and profile photographs with reference points were taken and analyzed using ImageJ® software to study the craniofacial morphology. PSG data were analyzed for correlation with craniofacial features. STROBE guidelines were strictly adopted during the research presentation. Results: The sample included 52 syndromic patients (50% females, mean age 9.38 ± 3.36 years) diagnosed with 17 different syndromes, of which 24 patients had craniofacial photography analysis carried out. Most of the sample (40%) had severe OSA, while only 5.8% had no OSA. Down's syndrome (DS) was the most common syndrome (40%) followed by Goldenhar syndrome (5%), Pierre Robin Sequence (5%), and other syndromes. The severity of AHI was significantly correlated with decreased midfacial height. increased thyromental angle and cervicomental angle, decreased mandibular angle, and decreased upper facial height. All patients with DS were diagnosed with OSA (57% severe OSA), and their ODI was significantly correlated with increased intercanthal distance. Obesity was not correlated to the severity of AHI for syndromic patients. Conclusions: Decreased midfacial height and obtuse thyromental angle were correlated with increased AHI for syndromic patients. Increased intercanthal distance of DS patients could be a major predictor of OSA severity. Obesity does not seem to play a major role in the severity of OSA for syndromic patients. Further studies with larger samples are necessary to confirm these findings.

The influence of obstructive sleep apnea syndrome on orthodontic treatment decisions in children and adolescents. Part 1: OSA phenotypes, treatment temporality and reciprocal effects on growth / L'influence du syndrome d'apnées obstructives du sommeil sur la décision thérapeutique orthodontique chez l'enfant et l'adolescent. Partie 1 : Phénotypes du SAOS, temporalité des traitements et effets réciproques sur la croissance

Introduction: Pediatric OSAS is a complex condition, comprising a plurality of clinical signs, complicated by the phenomena of growth. Its etiology is dominated by the hypertrophy of lymphoid organs, but obesity and certain craniofacial and neuromuscular tone abnormalities also contribute. Material and Method: The authors summarize the interrelations between pediatric OSAS endotypes, phenotypes and orthodontic anomalies. They report clinical practice recommendations on the multidisciplinary management of pediatric OSAS and define the place and timing of orthodontics. Results: There is an indication for treatment of pediatric OSAS for an OAHI greater than 5/h, regardless of comorbidity, as well as for symptomatic children, whose OAHI is between 1-5/h. The first line of treatment is adenotonsillectomy, but it does not always normalize the OAHI. Complementary treatments are often necessary: early orthodontics (rapid maxillary expansion, myofunctional appliances), oral reeducation, as well as the management of obesity and allergies. Careful watching, without treatment is possible for mild cases with few symptoms, as pediatric OSAS tends to resolve naturally with growth. Discussion: The therapeutic approach is stratified, depending on the severity of OSAS and the child's age. In terms of orthodontic repercussions, obesity is associated with earlier maturation and some facial morphological differences, while oral hypotonia and nasal obstruction can alter facial growth, promoting mandibular hyperdivergence and maxillary deficiency. Conclusion: Orthodontists are in a privileged position for the detection, follow-up and certain treatments of OSAS.

Introduction: Le syndrome d'apnées obstructives du sommeil (SAOS) pédiatrique est une pathologie complexe, comportant une pluralité de signes cliniques, compliqués par les phénomènes de croissance. Son étiologie est dominée par l'hypertrophie des organes lymphoïdes, mais l'obésité, certaines anomalies cranio-faciales ou du tonus neuromusculaire y contribuent. Matériel et méthode: Les auteurs font la synthèse des interrelations entre endotypes, phénotypes du SAOS pédiatrique et anomalies orthodontiques. Ils résument les recommandations sur la prise en charge pluridisciplinaire du SAOS, définissant la place des traitements orthodontiques. Résultats: Une indication de traitement du SAOS pédiatrique existe pour un indice d'apnées/hypopnées obstructives (IAHO) supérieur à 5/h, indépendamment de comorbidité, ainsi que pour les enfants symptomatiques, avec un IAHO entre 1 et 5/h. La première ligne de traitement est l'adéno-amygdalectomie, qui ne permet pas toujours de normaliser l'IAHO. Des traitements complémentaires sont souvent nécessaires : orthodontie précoce (expansion maxillaire rapide, appareils myofonctionnels), rééducation orale/hygiène nasale, ainsi que la prise en charge de l'obésité et des allergies. Une surveillance attentive sans traitement est possible pour les cas peu sévères et peu symptomatiques, car le SAOS a tendance à se résoudre naturellement avec la croissance. Discussion: L'approche thérapeutique est stratifiée, en fonction de la sévérité du SAOS et de l'âge de l'enfant. Au niveau des répercussions orthodontiques, l'obésité est associée à une maturation plus précoce et à des différences morphologiques faciales, alors que l'hypotonie orale et l'obstruction nasale peuvent favoriser l'hyperdivergence mandibulaire et la déficience maxillaire. Conclusion: Les orthodontistes sont dans une position privilégiée pour le dépistage, le suivi et certains traitements du SAOS.

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.

The effects of mandibular advancement appliance therapy on the sequence of jaw-closing muscle activity and respiratory events in individuals with obstructive sleep apnea.

PURPOSE: To determine the effects of a mandibular advancement appliance (MAA) on sequences of jaw-closing muscle activity (JCMA) and apneic or hypopneic event (AHE) in individuals with obstructive sleep apnea (OSA). METHODS: Individuals with OSA were included in a secondary analysis of a randomized controlled crossover trial, in which two ambulatory polysomnographic recordings were performed: one with MAA in situ and the other without MAA. A time span of 16 s between JCMA and AHE was applied to classify JCMAs into four sequences: (1) JCMA occurs before AHE (B-type); (2) both events occur simultaneously (S-type); (3) JCMA occurs after AHE (A-type); and (4) JCMA is time-unrelated to AHE (U-type). The effects of MAA on the distribution of these sequences were analyzed by Wilcoxon signed-rank test. RESULTS: Among 16 individuals (10 men, mean age 51.3 ± 8.5 years) baseline apnea-hypopnea index and JCMA index were 23.8 ± 16.0 events/h and 10.8 ± 10.3 events/h, respectively. In both conditions, i.e., without and with MAA, most JCMAs were U-type (48% and 65%, respectively), followed by A-type (41% and 22%), B-type (25% and 21%), and S-type (2% and 1%). With MAA in situ, only the A-type JCMA index decreased significantly (P = 0.005), while B-type, S-type, and U-type JCMA indices did not change significantly (all P > 0.05). CONCLUSION: MAA therapy only significantly reduces the jaw-closing muscle activities that occur after apneic or hypopneic events in individuals with OSA. TRIAL REGISTRATION: www. CLINICALTRIALS: gov (NCT02011425); December 13, 2013.

Adherence and efficacy of mandibular advancement splint treatment of sleep-disordered breathing during pregnancy: a pilot study.

PURPOSE: Sleep-disordered breathing (SDB) is common in pregnancy and is associated with adverse health consequences for both mother and child. Mandibular advancement splints (MAS) have been shown to improve sleep quality, daytime sleepiness and snoring in non-pregnant women. The effectiveness of MAS for treating SDB in pregnancy is unknown. This pilot study aimed to evaluate the efficacy and adherence to MAS in pregnant women with SDB. METHODS: Women with mild-moderate SDB (apnea-hypopnea index (AHI) 10-29/h) on level 2 polysomnography (PSG) performed at 22.0 ± 5.5 weeks' gestation were treated with a MAS during pregnancy to 6 months postpartum. An embedded micro-recorder measured adherence. PSG was repeated while on titrated treatment, and off treatment in the postpartum period. RESULTS: Among 17 women completing the study, MAS was worn ≥ 4 h/night for 57.5 ± 36.7% of nights during the antepartum period. While using MAS, nightly snoring time decreased from 25.9 ± 24.5% at baseline to 6.4 ± 7.8% when treated during pregnancy (p = .003). AHI decreased from 17.6 ± 5.1 to 12.9 ± 6.3 (p = .02) and fell by ≥ 30% and below 15/h in 60% of participants. During the postpartum period, MAS was used for ≥ 4 h/night on 24.8 ± 27.9% of nights. Moreover, the mean AHI off MAS was 17.9 ± 13.1; 88% of women had persistent SDB (AHI ≥ 10). CONCLUSIONS: In this cohort, treatment efficacy and objective adherence were variable. Device use was less frequent in the postpartum period even though a substantial number of women had persistent SDB after delivery. Clinical trial registered with  www. CLINICALTRIALS: gov number: NCT03138291.

Dental sleep-related conditions and the role of oral healthcare providers: A scoping review.

Dental sleep medicine as a discipline was first described about a quarter of a century ago. Snoring, obstructive sleep apnea, sleep bruxism, xerostomia, hypersalivation, gastroesophageal reflux disease, and orofacial pain were identified as dental sleep-related conditions. This scoping review aimed to: i) identify previously unidentified dental sleep-related conditions; and ii) identify the role of oral healthcare providers in the prevention, assessment, and management of dental sleep-related conditions in adults. A systematic literature search was conducted in PubMed, Embase.com, Web of Science, and Cochrane. Studies that reported an actual or likely role of oral healthcare providers in the prevention, assessment, and/or management of sleep-related conditions were included. Of the 273 included studies, 260 were on previously listed dental sleep-related conditions; the other 13 were on burning mouth syndrome. Burning mouth syndrome was therefore added to the list of dental sleep-related conditions for the first aim and categorized into sleep-related orofacial pain. For the second aim, the role of oral healthcare providers was found to be significant in the prevention, assessment, and management of obstructive sleep apnea and sleep bruxism; in the assessment and management of snoring, sleep-related orofacial pain, and oral dryness; and in the assessment of sleep-related gastroesophageal reflux condition.

Sleep Quality and Comfort Reported by Sleep Bruxism Individuals Wearing the Occlusal Splint and Mandibular Advancement Splint: Revisiting Two Crossover Studies.

PURPOSE: To assess (1) whether an occlusal splint (OS) or mandibular advancement splint (MAS) allowed better sleep quality and was more comfortable in individuals with sleep bruxism (SB); and (2) the relationship between sleep quality, comfort, and reduction in RMMA related to SB. MATERIALS AND METHODS: Polysomnographic data from 21 SB subjects (mean ± SD age 25.6 ± 4.5 years) collected in two previous studies were compared. Morning self-reports on sleep quality and comfort of the oral device, polysomnographic data, and RMMA index data from no-device nights were compared to nights using an OS or MAS. The reduction ratio of the RMMA index was calculated for both devices. A responder to the oral device was identified when the RMMA index was less than 2 and when it showed a reduction of at least 50% from the no-device control night. RESULTS: Self-reports for sleep quality and comfort of the oral device showed a mild advantage of the OS when compared to the MAS (r2 = 0.47, r2 = 0.32; P ≤ .01). In responders, the MAS induced a greater reduction in the RMMA index (P = .03) than the OS. CONCLUSIONS: In the short term, the comfort of the oral device seemed to influence sleep quality in SB individuals. However, despite the slightly higher degree of comfort offered by the OS, the MAS induced a greater effect on the RMMA index. Int J Prosthodont 2022;36:138-147. doi: 10.11607/ijp.7525.

Patient-reported Differences in Obstructive Sleep Apnea Care between Jurisdictions with and without Government Funding for Continuous Positive Airway Pressure.

Rationale: Funding for obstructive sleep apnea (OSA) treatment may impact how patients access care, wait times, and costs of care. Objectives: The aim of this study was to compare differences in diagnosis and treatment of OSA between Canadian jurisdictions with and without public funding for continuous positive airway pressure (CPAP). Methods: We administered an anonymous internet survey to Canadian adults reporting a physician diagnosis of OSA. Responses were categorized on the basis of whether the respondent's province provided full or partial funding for CPAP therapy for all patients. We assessed wait times for diagnosis and treatment, patient-borne costs, and model of care delivery compared between jurisdictions with and without universal CPAP funding. Results: We received 600 responses representing all Canadian provinces and territories. The median (interquartile range) age was 59 (49-66) years; 57% were male, and 21% were from rural settings. Patients living in provinces without public CPAP funding (n = 419) were more likely to be diagnosed using home sleep apnea testing (69% vs. 20%; P = 0.00019). Wait times were similar after adjustment for demographics, disease characteristics, and model of care. Although patient-borne costs of care were similar between jurisdictions, patients from regions without CPAP funding reported that cost had a greater influence on the choice of therapy. Sleep specialists were more commonly involved in OSA care in regions with CPAP funding. There was no difference in the current use of therapy between jurisdictions with and without public funding. Conclusions: This survey study demonstrates that public funding for CPAP therapy impacts how Canadians access OSA care but is not associated with differences in wait times or costs. Future research is required to determine the impact of different funding models for OSA care on clinical outcomes.

Oral appliances reduce masticatory muscle activity-sleep bruxism metrics independently of changes in heart rate variability.

OBJECTIVES: Sleep bruxism (SB) is associated with physiological activities including sympathetic autonomic system dominance and sleep micro-arousal. While oral appliances (OA) are used to prevent SB harmful effects, the influence of OAs physiological mechanisms during sleep is unknown. The aim of this study is to assess whether heart rate variability (HRV) changes, as a marker of autonomic nervous system activity, would be associated with the OA mechanism of action on SB using occlusal splint (OS) and mandibular advancement splint (MAS). MATERIALS AND METHODS: A retrospective analysis, from data previously collected in 21 participants with SB (25.6 ± 4.5 years) with polysomnographic recordings, was done. HRV data were compared between a reference night (no-device) and ones during which OS or MAS was used in a crossover study design. Rhythmic masticatory muscle activity (RMMA) index was compared between nights. HRV was evaluated using autoregressive model analysis for three sections: baseline (distance from RMMA), immediately before, and after RMMA period. RESULTS: A significant reduction in RMMA index, when wearing OA during sleep, was observed (P < 0.01), but was not associated with HRV parameters change. HRV significantly changed after RMMA onset for nights with OA during non-REM sleep in comparison with baseline (P < 0.02). CONCLUSIONS: The usage of OAs for SB participants reduced RMMA, but most likely independently of changes in HRV linked to the mechanism associated with SB genesis. CLINICAL RELEVANCE: Wearing OA seems to reduce grinding noise and protect from dental injuries but does not seem to influence SB genesis.

Accuracy of sleep bruxism scoring based on electromyography traces of different jaw muscles in individuals with obstructive sleep apnea.

STUDY OBJECTIVES: Sleep bruxism is characterized by rhythmic masticatory muscle activity (RMMA). This study aimed to determine the number and type of jaw muscles needed for a valid RMMA scoring in individuals with obstructive sleep apnea. METHODS: Ten individuals with obstructive sleep apnea (4 males; age, 50.1 ± 8.1 years) were included in this study. RMMA was scored using 1 or more of the following jaw muscles' electromyography (EMG) traces of polysomnography recordings: bilateral masseter and temporalis (4MT; the reference standard), unilateral masseter (1M), bilateral masseter (2M), unilateral temporalis (1T), bilateral temporalis (2T), unilateral chin EMG (1C), and bilateral chin EMG (2C). RESULTS: 1M, 2M, 1T, and 2T showed excellent agreement with 4MT (intraclass correlation coefficient = 0.751, 0.976, 0.815, and 0.950, respectively), while 1C and 2C presented fair agreement (intraclass correlation coefficient = 0.662 and 0.657). In addition, 2M and 2T displayed good sensitivity (87.8% and 72.0%) and positive predictive value (83.1% and 76.0%). In contrast, 1M and 1T had good sensitivity (88.4% and 87.8%) but fair positive predictive value (60.1% and 53.2%). 1C and 2C showed poor sensitivity (41.1% and 40.3%) and fair positive predictive value (62.9% and 60.6%). CONCLUSIONS: Polysomnography with bilateral masseter or temporalis muscle EMG traces is regarded valid in RMMA scoring in individuals with obstructive sleep apnea. In contrast, unilateral masseter or temporalis muscle EMG showed only fair accuracy, and chin EMG had poor accuracy. Consequently, these montages cannot be recommended for RMMA scoring in the presence of obstructive sleep apnea. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: The Effects of Oral Appliance Therapy on Masseter Muscle Activity in Obstructive Sleep Apnea; URL: https://clinicaltrials.gov/ct2/show/NCT02011425; Identifier: NCT02011425. CITATION: Li D, Aarab G, Lobbezoo F, Arcache P, Lavigne GJ, Huynh N. Accuracy of sleep bruxism scoring based on electromyography traces of different jaw muscles in individuals with obstructive sleep apnea. J Clin Sleep Med. 2022;18(6):1609-1615.

Socioeconomic inequalities in pediatric obstructive sleep apnea.

STUDY OBJECTIVES: To examine the association between multiple measures of socioeconomic status (SES) and objectively measured obstructive sleep apnea (OSA) in a Canadian pediatric population. METHODS: This was a cross-sectional study of 188 children (4-17 years, mean age 9.3 ± 3.5 years) prospectively recruited from two hospital sleep clinics in Canada, using multivariable-adjusted linear and logistic regression of five measures of SES including parental education, income, social class, geographic location, and perceived SES based on the MacArthur Scale of Subjective Social Status, assessed in relation to four polysomnographic OSA variables including apnea-hypopnea index, apnea index, mean oxygen saturation level, and oxygen desaturation index. RESULTS: Overall, low household-level SES appeared to be associated with both frequency (apnea index ≥ 1 events/h) and severity (apnea-hypopnea index ≥ 5 events/h) of OSA in children, with maternal education showing the most consistent and significant associations. Specifically, children with mothers reporting less than high school education had nearly three times the odds of having OSA after controlling factors including body mass index (odds ratio 2.96 [95% confidence interval, 1.05-8.37]), compared to university-educated participants. Consistent associations were also observed for geographic location with less frequency and severity of OSA among nonurban children. Perceived SES was minimally inversely associated with our outcomes. CONCLUSIONS: This cross-sectional, multicenter study demonstrated that SES factors are linked to the occurrence and severity of OSA in children. Results indicated the need to incorporate the screening of SES in the diagnostic process of pediatric OSA to provide more targeted intervention and patient-centered care. CITATION: Park JW, Hamoda MM, Almeida FR, et al. Socioeconomic inequalities in pediatric obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):637-645.

Comparison of anatomic and aerodynamic characteristics of the upper airway among edentulous mild, moderate, and severe obstructive sleep apnea in older adults.

STUDY OBJECTIVES: First, to compare the upper airway's anatomic and aerodynamic characteristics of the edentulous older adults who experience mild, moderate, and severe obstructive sleep apnea (OSA). Second, to examine the correlation between the severity of OSA and the anatomic and aerodynamic characteristic(s) of the upper airway in these edentulous individuals. METHODS: NewTom5G cone beam computed tomography scans of 58 edentulous individuals with mild, moderate, and severe OSA were included in this analysis. 1) Computational models of the upper airway were reconstructed based on cone beam computed tomography images and the anatomical and aerodynamic characteristics of the upper airway were examined by an observer blind to OSA severity. 2) Pearson correlation analysis was used to determine the correlation between apnea-hypopnea index and the anatomic and aerodynamic characteristics of the upper airway. RESULTS: Compared with edentulous patients with mild and moderate OSA, those with severe OSA have a more hourglass-shaped upper airway. The severity of OSA, namely, apnea-hypopnea index, was significantly correlated with the length, shape, and minimum cross-sectional area of the upper airway. During inspiration, the mean velocity of the airflow within the upper airway of the edentulous patients with severe OSA was higher than that of patients with mild and moderate OSA. During both inspiration and expiration, apnea-hypopnea index was found to be significantly correlated with maximum velocity (P = .05) and airway resistance (P = .024, 0.038). CONCLUSIONS: The edentulous patients with severe OSA have a more hourglass-shaped upper airway. The findings also suggest that, during inspiration, the airflow travels faster in edentulous patients with severe OSA than in those with mild or moderate OSA. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: The Effect of Nocturnal Wear of Dentures on Sleep and Oral Health Related Quality of Life; URL: https://clinicaltrials.gov/ct2/show/NCT01868295; Identifier: NCT01868295. CITATION: Chen H, Elham E, Li Y, et al. Comparison of anatomic and aerodynamic characteristics of the upper airway among edentulous mild, moderate, and severe obstructive sleep apnea in older adults. J Clin Sleep Med. 2022;18(3):759-768.

Associations between sleep bruxism and other sleep-related disorders in adults: a systematic review.

OBJECTIVE: Systematic reviews on sleep bruxism (SB) as a comorbid condition of other sleep-related disorders are lacking. Such reviews would contribute to the insight of sleep clinicians into the occurrence of SB in patients with other sleep-related disorders, and into the underlying mechanisms of such comorbid associations. This systematic review aimed: 1. to determine the prevalence of SB in adults with other sleep-related disorders; and 2. to determine the associations between SB and other sleep-related disorders, and to explain the underlying mechanisms of these associations. METHODS: A systematic search on SB and sleep-related disorders was performed in PubMed, Embase, Cochrane Library, and Web of Science to identify eligible studies published until May 15, 2020. Quality assessment was performed using the Risk of Bias Assessment tool for Non-randomized Studies. RESULTS: Of the 1539 unique retrieved studies, 37 articles were included in this systematic review. The prevalence of SB in adult patients with obstructive sleep apnea, restless leg syndrome, periodic limb movement during sleep, sleep-related gastroesophageal reflux disease, REM behavior disorder (RBD), and sleep-related epilepsy was higher than that in the general population. The specific mechanisms behind these positive associations could not be identified. CONCLUSIONS: SB is more prevalent in patients with the previously mentioned disorders than in the general population. Sleep arousal may be a common factor with which all the identified disorders are associated, except RBD and Parkinson's disease. The associations between SB and these identified sleep-related disorders call for more SB screening in patients with the abovementioned sleep-related disorders.

Effects of nocturnal wearing of dentures on the quality of sleep and oral-health-related quality in edentate elders with untreated sleep apnea: a randomized cross-over trial.

STUDY OBJECTIVES: This study aims to assess whether the nocturnal wear of dentures has an effect on the quality of sleep and oral-health-related quality of life of the edentulous elderly with untreated sleep apnea. METHODS: A single-blind randomized cross-over design with two sequences and two periods was used. Participants (n = 77) were randomly assigned either to sequence 1 (nocturnal wear followed by nocturnal nonwear of the denture for 30-30 days) or sequence 2 (nocturnal nonwear followed by nocturnal wear of denture for 30-30 days). The primary sleep outcome was the quality of sleep, assessed through sleep fragmentation measured as Apnea-Hypopnea Index (AHI) and respiratory arousal from portable polysomnography. Secondary outcomes were daytime sleepiness, sleep quality (Pittsburgh Sleep Quality Index, PSQI) and oral-health-related quality of life measured by validated questionnaires. RESULTS: The mean paired difference in AHI scores for the period of wearing versus not wearing dentures at night was small 1.0 event per hour (p = 0.50; 95% confidence interval (CI) = -2.0 to 4.1). The mean respiratory arousal index was higher when wearing dentures at night than when not wearing dentures at night, with a mean paired difference of 2.3 events per hour (p = 0.05; 95% CI = 0.0 to 4.6). No difference in sleepiness and PSQI were noted. Wearing dentures at night resulted in a statistically significantly higher mean score of psychological discomfort when compared to not wearing dentures at night. CONCLUSIONS: The results provide some support to usual practice guidelines to remove dentures at night in edentulous elders suffering from sleep apnea. CLINICAL TRIAL REGISTRATION: NCT01868295.

Research routes on improved sleep bruxism metrics: Toward a standardised approach.

A recent report from the European Sleep Research Society's task force "Beyond AHI" discussed an issue that has been a long-term subject of debate - what are the best metrics for obstructive sleep apnoea (OSA) diagnosis and treatment outcome assessments? In a similar way, sleep bruxism (SB) metrics have also been a recurrent issue for >30 years and there is still uncertainty in dentistry regarding their optimisation and clinical relevance. SB can occur alone or with comorbidities such as OSA, gastroesophageal reflux disorder, insomnia, headache, orofacial pain, periodic limb movement, rapid eye movement behaviour disorder, and sleep epilepsy. Classically, the diagnosis of SB is based on the patient's dental and medical history and clinical manifestations; electromyography is used in research and for complex cases. The emergence of new technologies, such as sensors and artificial intelligence, has opened new opportunities. The main objective of the present review is to stimulate the creation of a collaborative taskforce on SB metrics. Several examples are available in sleep medicine. The development of more homogenised metrics could improve the accuracy and refinement of SB assessment, while moving forward toward a personalised approach. It is time to develop SB metrics that are relevant to clinical outcomes and benefit patients who suffer from one or more possible negative consequences of SB.

The effects of mandibular advancement appliance therapy on jaw-closing muscle activity during sleep in patients with obstructive sleep apnea: a 3-6 months follow-up.

STUDY OBJECTIVES: The main aim of this study was to investigate the effects of mandibular advancement appliance (MAA) therapy on jaw-closing muscle activity (JCMA) time-related to respiratory arousals, and on JCMA time-related to nonrespiratory arousals in patients with obstructive sleep apnea. METHODS: Eighteen patients with OSA (mean ± standard deviation = 49.4 ± 9.8 years) with a mean ± standard deviation apnea-hypopnea index of 22.0 ± 16.0 events/h of sleep participated in a randomized controlled crossover trial in which two ambulatory polysomnographic recordings, 1 with an MAA in situ and another without the MAA in situ, were performed. JCMA was quantified as the sum of rhythmic masticatory muscle activities and other orofacial activities. RESULTS: Significant reductions in the apnea-hypopnea index (Z = -2.984; P = .003), in the respiratory arousal index (Z = -2.896; P = .004), and in the JCMA time-related to respiratory arousal index (Z = -3.434; P = .001) were found with MAA in situ. On the nonrespiratory arousal index, and on the JCMA time-related to nonrespiratory arousal index, MAA had no significant effect (T = 2.23; P = .82; and Z = -0.66; P = .51, respectively). CONCLUSIONS: This study shows that effective mandibular advancement appliance therapy significantly reduces jaw-closing muscle activities time-related to respiratory arousals in OSA patients. Future studies are needed to confirm these findings in obstructive sleep apnea patients with comorbid sleep bruxism. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: The Effects of Oral Appliance Therapy on Masseter Muscle Activity in Obstructive Sleep Apnea; Identifier: NCT02011425.