Association of periodontitis and cognitive impairment: A systematic review and meta‐analysis

Abstract

AbstractBackgroundEmerging evidence suggests link between poor periodontal status and cognitive impairment. This review systematically assessed longitudinal evidence on the association of periodontitis and tooth loss with cognition.MethodsComprehensive literature search for studies examining effect of periodontitis on cognition was conducted on two electronic databases, Medline and Scopus. Longitudinal studies having periodontitis or its surrogate measure (tooth loss) as exposure and cognition as outcome were included. Meta‐analysis was conducted on RevMAN‐5 software. Primary random effects model analyzing the effect of periodontitis (all measures) on cognition was generated. Secondary analyses included models based on periodontal specific measures 1 and tooth loss. Quality assessment of included studies was conducted.ResultsOut of 97 studies, 16 were included in the systematic review. Meta‐analysis included 9 studies. In preliminary results, primary model showed significant association between periodontitis and cognitive impairment (OR=1.22, 95%CI:1.01–1.49, p=0.04). In secondary analyses, neither periodontitis (based on specific measures) nor tooth loss was associated with cognitive impairment. However, further stratification of tooth loss found significant association between partial tooth loss and cognitive impairment (OR=1.53, 95%CI:1.03–2.29, p=0.04). The overall quality of evidence was low.ConclusionPeriodontitis appears to contribute to overall risk of cognitive impairment. This association may be driven by specific aspects of periodontitis such as severity, chronicity and corresponding tooth count. However, firm conclusions cannot be drawn due to overall low quality of evidence and lack of coherent methodology among studies (e.g. variability across periodontal and cognitive assessments). Well‐designed longitudinal studies with larger sample size and including comprehensive and standardized assessment of both periodontal and cognitive status are warranted.