Oral Frailty as a Potential Contributor to Cognitive Decline in Older Adults: A Systematic Review

This systematic review aims to examine whether multidimensional oral frailty is associated with cognitive decline or cognitive impairment in adults aged 60 years and older. Oral frailty is conceptualized as a composite geriatric phenotype reflecting cumulative declines across multiple oral functional domains and assessed using validated multidimensional instruments (e.g., OF-5, OFI-6, OFI-8, or nationally defined oral hypofunction criteria). Observational studies (cross-sectional and longitudinal cohort designs) published between 2014 and February 2026 will be identified through systematic searches of PubMed/MEDLINE and Scopus, with supplementary screening of Google Scholar. Eligible studies must include community-dwelling older adults and use validated neuropsychological instruments (e.g., MMSE, MoCA, HDS-R) to assess cognitive outcomes. Risk of bias will be evaluated using the Newcastle–Ottawa Scale. Due to anticipated heterogeneity in oral frailty definitions, cognitive assessment tools, and analytical models, findings will be synthesized using a structured narrative approach. This review seeks to clarify the role of oral frailty as a potential contributor to cognitive decline in ageing populations.