title: Risk factors of early childhood caries among children in Beijing: a case-control study.
abstract: BACKGROUND
  The prevalence of early childhood caries (ECC) among children in Beijing, China, has been increasing continuously though slowly. However, there is limited information about ECC in Beijing. The aim of this study was to identify risk factors of dental caries among preschool children in Beijing.
  
  
  METHODS
  For this case-control study, using a convenience sampling method, 787 children aged 3 and 4 years old were recruited; 386 children with caries constituted the early childhood caries (ECC) group and 401children without caries formed the caries-free (CF) group. Dental caries was diagnosed at the tooth surface level by two calibrated examiners according to the WHO 1997 criteria. A structured questionnaire was filled in by the children's main guardians. Mutans streptococci in non stimulated saliva and plaque were measured with the Dentocult SM Strip. Negative binomial regression was used for multivariate analysis.
  
  
  RESULTS
  Analysis of the data showed that level of mutans streptococci in dental plaque and history of dental visit were significantly correlated with the prevalence of caries and the mean dmfs score.
  
  
  CONCLUSIONS
  High level of plaque mutans streptococci is a risk factor for ECC in preschool children in Beijing. And longitudinal studies are needed to identify the causal relationships between the levels of mutans streptococci in dental plaque and caries development.
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China.
authors.forename: Cancan
authors.initials: C
authors.lastname: Fan
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China. t-xu@live.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.affiliation: Department of Preventive Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing, 100081, People's Republic of China. zhengsg86@gmail.com.
authors.forename: Shuguo
authors.initials: S
authors.lastname: Zheng
mesh_terms: D000068476:Beijing; D016022:Case-Control Studies; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D003773:Dental Plaque / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D012463:Saliva; D013295:Streptococcus mutans
keywords: Early childhood caries; Mutans streptococci; Risk factors