Tooth loss and risk of hip fracture: a prospective study of male Japanese dentists.

Objectives: To determine whether the number of teeth lost can predict the risk of subsequent hip fracture.

Methods: We followed up 9992 male Japanese dentists aged 50 years or more (mean age ± standard deviation [SD], 61.1 ± 9.6 years) for incidence of hip fracture. From 2001 through 2006, they completed a baseline questionnaire on lifestyle and health factors including the number of teeth lost (excluding third molars). Incidence rate ratios (IRRs) were estimated by fitting proportional hazard models.

Results: During the mean follow-up period of 6.0 years, 20 new cases of hip fracture occurred. Participants who had lost 15 or more teeth at baseline were at a significantly increased risk of hip fracture: the multivariate-adjusted IRRs were 4.1 (95% confidence interval [CI], 1.2-14.2) for loss of 15-27 teeth and 4.5 (1.1-18.0) for edentulousness relative to loss of 0-14 teeth (trend P, 0.028). Overall, the risk of hip fracture was weakly associated with the number of teeth lost: the IRR per tooth was 1.06 (95% CI, 1.01-1.12).

Conclusions: Tooth loss was slightly associated with a higher risk of subsequent hip fracture. The number of teeth lost might be informative in predicting this risk.