Occlusal support predicts tooth loss in older Japanese people

Objectives: Many older people lose their teeth. However, few studies have examined whether the number of remaining teeth or the amount of occlusal support is more important for tooth loss that occurs in older age after adjusting for systemic factors. The purpose of this study was to investigate comprehensively the factors related to tooth loss over a period of 6 years, including occlusal support in 70- and 80-year-old community-dwelling Japanese people. Methods: This cohort study included 296 participants in the 70-year-old group and 232 in the 80-year-old group. The number of teeth of all participants was recorded at baseline and after 6 years, and the participants were divided into two groups according to the number of teeth lost (0 or 4 or more). Occlusal support was classified into three groups based on posterior occlusal support. Mean probing pocket depth, tooth brushing habits, frequency of dental check-ups, education level, economic status and systemic factors (carotid atherosclerosis, hypertension, diabetes mellitus, dyslipidemia, cognitive function and smoking habits) were evaluated. Multiple logistic regression analysis was performed to investigate the relationship of tooth loss with occlusal support and systemic factors. Results: Logistic regression analysis revealed that mean probing pocket depth (odds ratio [OR] = 5.70, 95% confidence interval [CI] = 2.70-12.04, P <.01) and posterior occlusal support (reference = Eichner class A; Eichner B1-3, OR = 4.33, 95% CI = 1.54-12.17, P <.01; Eichner B4 or C, OR = 6.16, 95% CI = 1.17-32.44, P =.03) were associated significantly with the loss of four or more teeth. Conclusions: This study revealed that age itself is not a predictor of multiple tooth loss in community-dwelling older Japanese people. Deep mean probing pocket depth and a lack of posterior occlusal support were significantly associated with the loss of four or more teeth.