Validity of self-reported tooth counts and masticatory status study of a Japanese adult population

J Oral Rehabil. 2018 May;45(5):393-398. doi: 10.1111/joor.12615. Epub 2018 Feb 18.


Self-reported measures of oral health are often used to assess oral health in populations or groups, but their validity or reliability needs repeated confirmation. The objective of this cross-sectional study was to evaluate the validity of self-reported tooth counts and masticatory status, using data obtained from a sample of Japanese adults. A total of 2356 adults aged 40 to 75 years participated in a questionnaire survey and a clinical oral examination from 2013 through 2016. Self-reported measures were compared with clinically measured values. For tooth counts, mean clinical and self-reported tooth counts in all participants were 23.68 and 23.78 teeth, and no significant difference was detected. Spearman's, Pearson's and intra-class correlation coefficients between clinical and self-reported tooth counts were 0.771, 0.845 and 0.843, respectively. According to the Bland-Altman analysis, the mean difference between clinical and self-reported tooth counts was -0.098 (95% CI: -0.242, 0.047). The upper limit of agreement was 6.919 (95% CI: 6.669, 7.169), and the lower limit of agreement was -7.115 (95% CI: -7.365, -6.865). No significant fixed or proportional bias was observed. For masticatory status, the crude or age- and gender-adjusted mean numbers of total teeth, posterior teeth and 3 kinds of functional tooth units significantly decreased with the deterioration of masticatory status. This study indicated that self-reports were within an acceptable range of clinical measures. Therefore, self-reports were considered valid alternatives to clinical measures to estimate tooth counts and masticatory status in a current Japanese adult population.

Keywords: masticatory status; oral health; reliability; self-report; tooth count; validity.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aging
  • Cross-Sectional Studies
  • Dental Health Surveys / standards*
  • Female
  • Humans
  • Japan / epidemiology
  • Male
  • Mastication / physiology
  • Middle Aged
  • Oral Health / statistics & numerical data*
  • Reproducibility of Results
  • Self Report / standards*
  • Tooth Loss / epidemiology*