title: [Study of dental caries and correlated factors of 12-year-old children in Dongxiang, Baoan and Yugu races].
abstract: OBJECTIVE
  To investigate the epidemiology of dental caries and its correlated factors of 12-year-old children in Dongxiang, Baoan and Yugu races.
  
  
  METHODS
  According to the method of third national oral health epidemiologic investigation, 448 12-year-old children in Dongxiang, Baoan and Yugu races were randomly collected and the epidemiological investigation of dental caries, oral bacteriological detection and oral hygiene behavior were carried out.
  
  
  RESULTS
  1) The caries prevalence rate of Dongxiang, Baoan and Yugu races were 40.52%, 44.29%, 46.45%, respectively. The average caries of Dongxiang, Baoan and Yugu races were 0.92, 0.90, 1.13, respectively. 2) The main ranks of Streptococcus mutans in saliva were class 2 and class 3 in Dongxiang and Baoan races. However, it was class 0 or class 1 in Yugu race. The level of Streptococcus mutans in dental plaque was higher in Dongxiang and Baoan races than in Yugu race. 3) The children's everyday brushing rate was higher in Yugu race than in Dongxiang and Baoan races (P<0.01). But there were no difference between Dongxiang and Baoan races.
  
  
  CONCLUSIONS
  The caries prevalence rates of 12-year-old children in Dongxiang, Baoan and Yugu races are high. The main factors of high caries prevalence rate were low brushing rate and dental plaque couldn't be removed effectively. Oral health education should be strengthened in the three race areas.
authors.affiliation: Dept. of Stomatology, Medical Department of Northwest University for Nationalities, Lanzhou 730030, China.
authors.forename: Hai-jing
authors.initials: HJ
authors.lastname: Zhou
authors.forename: Hong-bing
authors.initials: HB
authors.lastname: Nie
authors.forename: Li-yang
authors.initials: LY
authors.lastname: Ma
authors.forename: Zhi-qiang
authors.initials: ZQ
authors.lastname: Li
authors.forename: Si-wu
authors.initials: SW
authors.lastname: Fu
authors.forename: Mei-tian
authors.initials: MT
authors.lastname: Liu
mesh_terms: D044466:Asian People; D002648:Child; D002681:China; D003731:Dental Caries; D003773:Dental Plaque; D005260:Female; D006801:Humans; D008297:Male; D009910:Oral Hygiene; D015995:Prevalence; D012463:Saliva; D013295:Streptococcus mutans