title: Validity of self-reported number of teeth and oral health variables.
abstract: BACKGROUND
  Oral condition and number of teeth were investigated by questionnaire in the Japan Multi-Institutional Collaborative Cohort (J-MICC Study). The aim of the present study was to assess the validity of the tooth number measure by comparing the self-reported number of teeth with the number of teeth determined at clinical dental examination.
  
  
  METHODS
  A self-administered questionnaire and dental examination were performed by 1275 participants of a company medical examination who requested dental check-up and 377 subjects of the J-MICC study. The validity of the tooth number measure was assessed by comparing the self-reported number of teeth with that determined at clinical examination. Spearman's rank correlation coefficient was calculated to quantitatively evaluate the validity.
  
  
  RESULTS
  In males, the mean clinically-examined and self-reported numbers of teeth were 26.5 and 24.8 teeth, respectively. In females, the mean clinically-examined and self-reported numbers of teeth were 26.4 and 25.5 teeth, respectively. There was a tendency toward underestimation of the number of natural teeth by self-reporting. A significant correlation was observed between the clinically-examined and self-reported numbers of teeth in total (ρ = 0.69) and both males (ρ = 0.70) and females (ρ = 0.67).
  
  
  CONCLUSIONS
  The self-reported oral health variables were valid and reflected clinical status. Further revision of the question on the remaining tooth in the questionnaire improves the validity of self-reported number of teeth.
authors.affiliation: Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan. d-matsui@koto.kpu-m.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Matsui
authors.affiliation: Department of Dental Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Dental Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Nishigaki
authors.affiliation: Department of Dental Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Fumitaro
authors.initials: F
authors.lastname: Miyatani
authors.affiliation: Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Watanabe
authors.affiliation: Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Teruhide
authors.initials: T
authors.lastname: Koyama
authors.affiliation: Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Ozaki
authors.affiliation: Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Nagato
authors.initials: N
authors.lastname: Kuriyama
authors.affiliation: Department of Dental Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Narisato
authors.initials: N
authors.lastname: Kanamura
authors.affiliation: Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, 465 Kajii-cho, Kamigyo-ku, Kyoto, 602-0841, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D009909:Oral Health; D057566:Self Report; D011795:Surveys and Questionnaires; D014070:Tooth; D016388:Tooth Loss
keywords: Number of teeth; Questionnaire survey; Self-report; Validity