Beyond the mouth: the impact of periodontal disease on dementia

Abstract

Data sources: The authors searched Medline via PubMed, Scopus, CINAHL, Web of Science, and PsycINFO for relevant studies published until April 2022.

Study selection: Longitudinal studies that assessed periodontal health as the exposure and cognitive decline and/or dementia as the outcome were included. Case reports, reviews, cross-sectional studies, and animal studies were excluded. DATA EXTRACTION AND SYNTHESIS: Two authors independently reviewed studies for inclusion, extracted data, and assessed study quality. Meta-analysis was conducted to generate pooled odds ratios (ORs) for cognitive decline and hazard ratios (HRs) for dementia. Sources of heterogeneity were explored through subgroup analyses.

Results: A total of 24 studies were included for cognitive decline and 23 for dementia. Poor periodontal health was associated with increased odds of cognitive decline (OR = 1.23; 95% CI: 1.05-1.44) and dementia (HR = 1.21; 95% CI: 1.07-1.38). Tooth loss also appeared to increase the risk independently. However, significant heterogeneity existed between studies.

Conclusions: Poor periodontal health may increase the risk of cognitive decline and dementia, but the quality of evidence was low. Further high-quality, longitudinal studies with standardized assessments are needed to establish causality.