# An updated systematic review and meta-analysis of tooth loss in patients with periodontitis and the risk of mild cognitive impairment

## TL;DR

This study finds that severe periodontitis and significant tooth loss are linked to a higher risk of mild cognitive impairment, despite no overall association between periodontitis or tooth loss and cognitive decline.

## Contribution

The study clarifies the relationship between periodontitis, tooth loss, and mild cognitive impairment using a meta-analysis with subgroup analyses.

## Key findings

- Severe periodontitis was significantly associated with mild cognitive impairment under specific diagnostic criteria.
- Significant tooth loss showed a statistically significant link to mild cognitive impairment.
- Overall, neither periodontitis nor tooth loss showed a strong association with increased MCI risk after full adjustment.

## Abstract

Conflicting evidence has shown a connection between tooth loss, periodontitis, and increased risk of mild cognitive impairment (MCI); thus, we conducted a meta-analysis to clarify this association.

PubMed, Embase, Web of Science, the Cochrane Library, and MEDLINE (up to March 2025) were searched. Cross-sectional and longitudinal studies were included. Fully-adjusted odds ratios (aORs) with the most severe form of periodontitis or tooth loss were pooled with a random effects model using STATA 18/MP software. Subgroup and sensitivity analyses were conducted to elucidate possible heterogeneity.

The meta-analysis of five studies showed that neither periodontitis nor tooth loss substantially increased MCI risk after full adjustment, with pooled aORs of 1.27 (95% CI: 0.87–1.86, I2 = 63.9%) and 1.22 (95% CI: 0.97–1.54, I2 = 53.8%), respectively. A significant association was found between periodontitis and MCI with low heterogeneity in the Centers for Disease Control and Prevention-American Academy of Periodontology diagnostic criteria for periodontitis subgroup (aOR of 2.78, 95%CI 1.54–5.02, I2 = 0.0%) and between MCI and significant tooth loss (aOR of 1.50, 95%CI 1.15–5.95, I2 = 0.0%). The sensitivity result confirmed the robustness of the results.

Overall, periodontitis and tooth loss were not statistically associated with increased MCI risk. Whereas the association between severe periodontitis and significant tooth loss and MCI was statistically significant. Thus, severe periodontitis and significant tooth loss were linked to decreased cognitive function.

PROSPERO CRD420251055491.