Incidence and predictors of self-reported tooth loss in a representative sample of Norwegian adults

The purpose of this study was to determine the self-reported 12-month incidence of tooth loss among Norwegian adults and to assess the association between tooth loss and some predictor variables.

Of a two-stage nation-wide, representative random sample (n = 3958), information was obtained from 2682 subjects aged 20-79 years and the response rate was 68%. Telephone or face-to-face interviews by interviewers employed by the Central Bureau of Statistics (CBS) of Norway. Information was collected about demographic characteristics, the number of natural teeth present, the number of teeth lost during the last 12 months, and belief in keeping natural teeth for life. The present analyses are based on 2520 persons 20-79 years of age.

The proportion of respondents who reported losing one or more teeth was 6.45% (95% confidence limits (CL) = 5.49, 7.41). The participants who reported extractions had lost on average 1.54 (range 1-9) teeth. Multiple logistic regression analysis revealed a borderline significant effect of the level of education (OR = 0.68, 95% CL = 0.46, 1.00), i.e. the odds of losing one or more teeth during the last 12 months were lower among persons with more than 12 years of education than among persons with less education. The explained variance was 1.9%.

The annual incidence rate of tooth loss among Norwegian adults was found to lie within the range reported from other industrialized countries. After controlling for socio-demographic variables and the number of teeth present, the only borderline significant predictor of the incidence of tooth loss was the level of education.