Can the relation between tooth loss and chronic disease be explained by socio-economic status? A 24-year follow-up from the Population Study of Women in Gothenburg, Sweden

The objective of this study was to evaluate the association between number of missing teeth and all cause, cardiovascular, and cancer mortality as well as morbidity and to explore whether socio-economic factors mediate this association. An ongoing prospective cohort study of 1462 Swedish women included a dental survey in 1968/69 with follow-up until 1992/93. The dental examination included a panoramic radiographic survey and a questionnaire. Number of missing teeth at baseline was analysed in a Cox proportional hazards model to estimate time to mortality and morbidity. Number of missing teeth, independently of socio-economic status variables (the husband's occupational category, combined income, and education) was associated with increased all cause mortality and cardiovascular disease mortality respectively (relative risk (RR): 1.36; 95% confidence interval (95% CI): 1.18-1.58) and (RR: 1.46; 95% CI: 1.15-1.85 per 10 missing teeth), but no associations were found for cancer mortality (RR: 1.18; 95% CI: 0.91-1.52). The relation between poor oral health and future cardiovascular disease could not be explained by measures of socio-economic status in this study.