Abstract
An association between mortality and dental status has been reported in several studies. These studies indicate that subjects with adequate dental status, defined as at least 16 teeth or at least 20 teeth, have a lower relative risk of mortality compared with those with fewer teeth or denture users. However, there is an obvious important confounding socio-economic factor. It may be impossible to demonstrate definitively whether the risk of death is directly related to tooth loss or whether such a risk is an indirect outcome of common underlying factors such as lifestyle. A more important issue for 21 st century dentistry, however, is whether dental treatment can decrease the risk of mortality among elderly people. While more elderly persons are retaining their own teeth, tooth loss remains a serious problem faced by the elderly in developed countries. To evaluate the influence of dental occlusion, with or without the use of dentures, on mortality in community-dwelling elderly persons, we conducted an 8-year cohort study at Kure city in Japan. 1, 030 randomly selected healthy independent elderly aged 65 or over took part in this study. Subjects were classified into three groups according to the presence or absence of maxillo-mandibular tooth contacts. Subjects with no maxillomandibular tooth contacts were further subdivided into those with and without dentures. Data on mortality were obtained from Kure City Council in September 2003. Cox regression models were used in analyzing the risk of death with gender and age as covariates. The results showed individuals whose teeth had contact in at least the bilateral premolar regions at baseline had 0.78 times (95% CI: 0.60-0.99) lower risk of death during the succeeding 8 years than those who had no occlusion. Among those who had no occlusion with their own teeth, the risk of mortality among denture non-users was 1.52 times (95% CI: 1.25-1.83) higher than the risk of denture users. These results support the view that, in the elderly, poor dental occlusion is associated with an increased risk of mortality and that the use of dentures is associated with a decreased risk of mortality.
