Background: The association between cognitive neurodegenerative disease and oral diseases has been under great interest recently. Several studies have suggested a connection between periodontitis and Alzheimer's disease (AD) or other neurodegenerative disorders.
Objective: This study aimed to review the potential mechanisms between oral diseases and neurodegenerative diseases.
Methods: The study was executed as a literature review of English-language publications from 2018-2022. The databases used for the search were PubMed, Cochrane, Scopus, and Web of Science. The search phrases used were "neurodegenerative diseases" AND "oral health" and "neurodegenerative diseases" AND "oral diseases."
Results: The linkage between the two disease groups was observed in several distinct publications and several potential mechanisms were found. The link between periodontitis and AD proved to be the most significant. The effect was accentuated in elderly people where individuals possessed also other risk factors for neurodegenerative diseases and had generally worse oral health conditions.
Conclusions: Oral diseases may be risks for neurodegenerative changes along many different pathways. Good oral health should be acknowledged as a potential preventative or risk-reducing act against neurodegenerative diseases.
Keywords: Alzheimer's disease; chronic inflammation; dementia; neurodegenerative diseases; oral diseases; oral microbiota; oral-brain axis.