Tooth loss may be an important risk indicator for cognitive decline according to a recent study published in the Journal of Dentistry.

A group of researchers conducted a study to investigate whether tooth loss and related loss of occluding tooth pairs, were associated with cognitive decline in a group of community-dwelling older men and women from Ireland.
A group of 2508 men and women, aged 50–93 years, underwent a dental examination as part of The Irish Longitudinal Study of Ageing (TILDA). Global cognitive function was assessed using the mini-mental state examination (MMSE). The analysis included multiple logistic regression with adjustment for various confounders.

The Results of the study are:
The mean age of participants was 65.5 years (SD 8.1) and 55.3% of the group were female. Three hundred and twenty-nine (13.1%) of the cohort were classified as having a low MMSE with a score ≤ 27. After adjustment for confounding variables, compared to subjects with ≥ 20 teeth, the odds ratio for a low MMSE amongst edentulous was 1.55 (95% CI 1.03–2.34) p = 0.03, and for those with 1–19 teeth was 1.38 (95% CI 1.03–1.84) p = 0.04. Having < 10 natural occluding pairs and < 4 posterior occluding pairs is also associated with a low MMSE.
Thus, the researchers concluded that in this cross-sectional cohort study, tooth loss and related loss of occluding tooth pairs were associated with a low MMSE in a group of older adults from Ireland, independent of various known confounders. Dentists should be aware of the potential systemic health implications of patients presenting with tooth loss. Tooth loss may be an important risk indicator for cognitive decline.
Reference:
Tooth loss and cognitive decline in community-dwelling older Irish adults: A cross-sectional cohort study by Lewis Winning et al. published in the Journal of Dentistry.
https://www.sciencedirect.com/science/article/pii/S0300571222001348