title: Sleep bruxism in children: sleep studies correlate poorly with parental reports.
abstract: The prevalence of sleep bruxism (SB) is usually reported as highest during childhood and decreases with age. However, this is based on parental reports and self-reports in the absence of quantitative data. Moreover, although SB signs, symptoms, and cutoff criteria have been established in the adult population, they remain unassessed in the pediatric population.
  
  
  
  This study aims to classify SB in children according to sleep variables and rhythmic masticatory muscle activity (RMMA) frequency indexes and to determine associations with objective signs and symptoms of SB in comparison with parental reports.
  
  
  
  Thirty-two children (11.5 ± 0.3 years) recruited at the orthodontic clinic underwent a dental assessment and ambulatory sleep recording (type II). Parents responded to a validated screening questionnaire on tooth clenching and grinding. A two-step cluster analysis was performed to classify participants into RMMA frequency groups, as described subsequently, followed by one-way analysis of variance (ANOVA) to compare groups. Fisher's exact test was performed for analyzing the associations between the signs and symptoms according to RMMA.
  
  
  
  Three RMMA frequency groups were identified: low (n = 12), moderate-high (n = 13), and control (n = 7). Between-group comparisons for episodes per hour and bursts/hour were significant (p <0.001). No relationships were found between RMMA (presence/absence) and clinically assessed tooth wear or reports of tooth clenching or grinding or craniofacial complaints.
  
  
  
  RMMA frequency classification differs slightly between children and adults. No association was observed between parental reports and RMMA, suggesting the need to improve parental knowledge of children's SB.
authors.affiliation: Faculté de médecine dentaire, Université de Montréal, QC, Canada; Centre de recherche du CHU de Sainte-Justine, Montréal, QC, Canada. Electronic address: nelly.huynh@umontreal.ca.
authors.forename: N T
authors.initials: NT
authors.lastname: Huynh
authors.affiliation: SCSB, Montréal, QC, Canada.
authors.forename: E
authors.initials: E
authors.lastname: Desplats
authors.affiliation: Faculté de médecine dentaire, Université de Montréal, QC, Canada; Faculté de médecine dentaire, Université Laval, Quebec City, QC, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Bellerive
mesh_terms: D001143:Arousal / Q000502:physiology; D002648:Child; D003430:Cross-Sectional Studies; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008410:Masticatory Muscles / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D010290:Parents / Q000523:psychology*; D020186:Sleep Bruxism / Q000150:complications*; D011795:Surveys and Questionnaires
keywords: Classification; Clinical assessment; Orthodontics; Polysomnography; Questionnaires; Young adolescents