title: The influence of peer social networks on toothbrushing behaviour in Iranian adolescents in Mashhad.
abstract: OBJECTIVE
  This study aimed to assess the association between the quality and quantity of peer social networks and toothbrushing behaviours of Iranian adolescents in Mashhad. The second objective was to examine whether peer social networks go some way to explain the sex difference in toothbrushing behaviours in Iranian adolescents in Mashhad.
  
  
  METHODS
  A representative stratified random sample of 1132 sixth grade Iranian students in Mashhad, with an average age of 12.4 (SD = 0.8) years, answered a 37-item questionnaire. The questionnaire had items on sociodemographic characteristics (age, sex and parents' education level), education achievement (last year's final average mark), frequency of toothbrushing behaviours and peer social networks (number of close friends, frequency of meeting friends, club membership and quality of peer groups). Binary logistic regression analysis was employed to test the association between toothbrushing frequency and peer social networks.
  
  
  RESULTS
  Adolescents who met their friends moderately often and had stronger ties with their friends were more likely to brush their teeth twice or more a day; P = 0.05 and P < 0.001, respectively. Club membership and number of close friends were not associated with toothbrushing frequency. Girls were significantly more likely to brush their teeth twice or more a day. They had weaker peer social networks than boys (P < 0.001). When adjusted for sex and father's education level, all peer social networks variables were significantly associated with toothbrushing frequency. However, the interaction between sex and peer social networks variables was not significant.
  
  
  CONCLUSIONS
  Peer social networks are related to toothbrushing frequency among Iranian adolescents in Mashhad but do not explain the differences in toothbrushing frequency between sixth grade Iranian boys and girls.
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, UK. mojtabadorri@yahoo.com
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Dorri
authors.forename: Aubrey
authors.initials: A
authors.lastname: Sheiham
authors.forename: Richard
authors.initials: R
authors.lastname: Watt
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016009:Chi-Square Distribution; D002648:Child; D004522:Educational Status; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D010379:Peer Group; D012737:Sex Factors; D012944:Social Support; D012959:Socioeconomic Factors; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D014099:Toothbrushing / Q000523:psychology* / Q000706:statistics & numerical data