Can Tooth Loss Affect Your Brain?

Researchers have been paying closer attention to the relationship between oral health and brain health, and the findings are hard to ignore.

Multiple systematic reviews and meta-analyses have examined whether tooth loss is associated with cognitive decline and dementia. One of the most cited is a 2021 dose-response meta-analysis of 14 longitudinal cohort studies involving more than 34,000 adults. It found that individuals with greater tooth loss had a 1.48 times higher risk of cognitive impairment and a 1.28 times higher risk of dementia compared to those who retained more of their teeth.

These are significant numbers. But understanding what they do, and don't tell us matters just as much as the statistics themselves.

What Might Explain the Connection?

Scientists have proposed several mechanisms that could help explain why tooth loss and cognitive decline tend to appear together, though it's important to note these are still working hypotheses rather than proven causes.

The first is systemic inflammation. Periodontal disease and tooth loss are associated with elevated chronic inflammatory burden in the body, and that same inflammatory activity has been implicated in cognitive decline and dementia. Some reviews point to microbial pathways, including how oral bacteria may influence the gut-brain axis and trigger immune responses in the brain.
(Journal of Neurogastroenterology and Motility, 2019)

The second proposed pathway involves chewing and brain stimulation. Animal studies suggest that losing occlusal support the physical contact between upper and lower teeth during chewing, reduces sensory input to the brain, may affect cerebral blood flow, and has been associated with changes in the hippocampus, a region central to memory and learning. In other words, the mechanical act of chewing may play a role in keeping certain parts of the brain active.
(International Dental Journal, 2020)

Third, there's the matter of shared risk factors. Socioeconomic status, education level, diabetes, vascular health, and lifestyle behaviors are all associated with both tooth loss and dementia risk. This means some portion of the observed connection may reflect common underlying vulnerabilities rather than a direct biological link between teeth and cognition.
(GeroScience, 2023)

Correlation, Not Causation

This is an important distinction, and one the researchers themselves are careful to make. The studies in this area consistently show association, not proof that losing teeth directly causes dementia. In fact, when analyses are restricted to studies with longer follow-up periods of ten years or more, the association between tooth loss and dementia tends to weaken or become statistically non-significant. This raises the possibility of reverse causality: that early, undetected cognitive decline may lead to worse oral hygiene and care, rather than the other way around.

So while the association is real and worth taking seriously, the headlines that suggest tooth loss predicts dementia are telling only part of the story.

What the Research Does Support

Even with those caveats, there's a reasonable case for paying attention to oral health as part of long-term wellbeing. The same 2021 meta-analysis found that participants who wore dentures effectively restoring their chewing function, did not show significantly increased dementia risk. This suggests that maintaining chewing function, not just tooth count, may be part of what matters.

Maintaining good oral hygiene and preserving chewing function is associated with better cognitive outcomes in observational research. Whether that relationship is causal or not, the habit of consistent oral care is one of the lower-effort, higher-upside investments you can make in your overall health.

Tools like the Feno Smartbrush, which combines thorough cleaning with built-in oral scanning, are designed to make that daily habit easier to maintain, so that staying on top of your oral health doesn't feel like one more thing on the list.

The science is still evolving, but the message is consistent: your mouth and your brain are more connected than most people realize. Taking care of one may be one of the simplest ways to support the other.