title: Reliability of self-reported toothbrushing frequency as an indicator for the assessment of oral hygiene in epidemiological research on caries in adolescents: a cross-sectional study.
abstract: BACKGROUND
  In the present state of knowledge regarding the etiology of dental caries, it is unacceptable for studies addressing factors associated with this outcome to disregard oral hygiene. Simple, valid methods are needed for the assessment of oral hygiene in adolescents to allow this condition to be properly investigated in epidemiological studies on caries and assist in the establishment of health promotion measures. The aim of the present study was to test the hypothesis that the self-reported toothbrushing frequency can be used as a proxy measure for clinical oral hygiene indices in epidemiological studies on dental caries in adolescents.
  
  
  METHODS
  A cross-sectional study was conducted with a representative sample (n = 589) of 12-year-old school children in a medium-sized city in southern Brazil. A detailed questionnaire addressing socio-demographic and economic characteristics was sent to primary caregivers. Adolescents answered a brief self-administered questionnaire on behavioral characteristics, including toothbrushing frequency and sugar intake. Samples of stimulated saliva were collected from the adolescents and evaluated for levels of mutans streptococci and lactobacilli using Dentacult kits I and II, respectively. Examiners who had undergone a training and calibration exercise (kappa > 0.81) performed the clinical examination of the adolescents. Caries experience was assessed using the decayed, missing and filled teeth index. Oral hygiene was determined using the Simplified Oral Hygiene Index and the Visible Plaque Index.
  
  
  RESULTS
  When the oral hygiene variables were used alone in the multiple models, significant associations with dental caries were found. When Simplified Oral Hygiene Index and/or Plaque Index were used together with toothbrushing frequency in the same model, only the latter was significantly associated with dental caries. A significant association was also found between self-reported toothbrushing frequency and the clinical indices.
  
  
  CONCLUSIONS
  Based on the present findings, self-reported toothbrushing frequency can be used as a proxy measure for clinical oral hygiene indices, which facilitates data collection in epidemiological studies addressing dental caries in adolescents.
authors.affiliation: Department of Stomatology, Federal University of Parana, Av. Prefeito Lothário Meissner, 632, Curitiba, Brazil. giovanasgil@yahoo.com.br.
authors.forename: Giovana S
authors.initials: GS
authors.lastname: Gil
authors.affiliation: Department of Stomatology, Federal University of Parana, Av. Prefeito Lothário Meissner, 632, Curitiba, Brazil. fransumie@gmail.com.
authors.forename: Francine S
authors.initials: FS
authors.lastname: Morikava
authors.affiliation: Department of Stomatology, Federal University of Parana, Av. Prefeito Lothário Meissner, 632, Curitiba, Brazil. gab_santin@hotmail.com.
authors.forename: Gabriela C
authors.initials: GC
authors.lastname: Santin
authors.affiliation: Department of Stomatology, Federal University of Parana, Av. Prefeito Lothário Meissner, 632, Curitiba, Brazil. tatipegoretti@hotmail.com.
authors.forename: Tatiana P
authors.initials: TP
authors.lastname: Pintarelli
authors.affiliation: Department of Stomatology, Federal University of Parana, Av. Prefeito Lothário Meissner, 632, Curitiba, Brazil. fabianfraiz@gmail.com.
authors.forename: Fabian C
authors.initials: FC
authors.lastname: Fraiz
authors.affiliation: Department of Stomatology, Federal University of Parana, Av. Prefeito Lothário Meissner, 632, Curitiba, Brazil. femoraisfe@gmail.com.
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Ferreira
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D003731:Dental Caries / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D016021:Epidemiologic Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D007778:Lactobacillus / Q000302:isolation & purification; D008297:Male; D009910:Oral Hygiene / Q000379:methods / Q000592:standards*; D016012:Poisson Distribution; D012044:Regression Analysis; D015203:Reproducibility of Results; D012463:Saliva / Q000382:microbiology; D012574:Schools; D013295:Streptococcus mutans / Q000302:isolation & purification; D013334:Students / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014099:Toothbrushing / Q000379:methods / Q000706:statistics & numerical data*