Tooth loss increases the risk of diminished cognitive function

The increase of cognitive impairment and its pathologic correlates, such as dementia and Alzheimer's disease, in aging populations is progressing worldwide and creating a significant burden on health systems. Better insight into the nature and extent of the association between oral health and cognitive function is of great importance since it could lead to preventive interventions for cognitive performance. Therefore, the objective of this review was to systematically examine if tooth loss leads to cognitive impairment and its most prevalent pathologic correlate (dementia).

Eligible study reports were identified by searching the MEDLINE (via Ovoid), EMBASE, PsycoINFO and Cochrane Library databases. Pooled hazard ratios with 95 percent confidence intervals were calculated with a random effects model. From 1,251 identified articles, 10 were included in the systematic review and eight in the meta-analysis. Random effects analysis showed, with statistically low heterogeneity, that individuals with less than 20 teeth were at a 20 percent higher risk for developing cognitive decline (hazard ratios equal 1.26, 95 percent confidence intervals equal 1.14 to 1.40) and dementia (hazard ratios equal 1.22, 95 percent confidence intervals equal 1.04 to 1.43) than those with greater than or equal to 20 teeth.

Based on the published literature, the results of this study show that the risk for cognitive impairment and dementia increases with loss of teeth. This information suggests that oral health strategies aimed to preserve teeth may be important in reducing risk of systemic disease.