Association between masticatory function and cognitive ability in mild cognitive impairment

Mastication is linked to cognitive function and influences brain activity, blood flow, and neurotrophic factors. A decrease in masticatory function may exacerbate mild cognitive impairment (MCI), a reversible condition affecting older adult. Identifying the masticatory factors associated with MCI could help guide interventions. To investigate the relationship between masticatory function and associated with MCI and identify oral functional factors that influence cognitive ability in older adult. A cross-sectional study was conducted on 137 participants (100 normal, 37 MCI), aged ≥ 65 years, recruited from Yonsei University Dental and Severance Hospitals (2020–2024). Participants with ≥ 20 teeth without systemic diseases or chewing problems were included. Objective assessments (e.g., tongue pressure TP, oral diadochokinesis ODK, and masseter muscle thickness MMT) and subjective evaluations (e.g., the Korean Mini-Mental State Examination, 2nd edition KMMSE-2, Food Intake Ability FIA) were performed. Statistical analyses were conducted to identify associations between masticatory factors and MCI. Significant differences in the number of remaining teeth, the number of posterior teeth, the Eichner index, TP, ODK (/pa/, /ta/, /ka/), and MMT (all p < 0.05) were detected between the normal and MCI groups. Multiple Logistic regression with Firth’ method revealed that posterior occlusal support (Eichner index), TP, ODK (/pa/, /ka/), and MMT were significantly associated with MCI. Posterior occlusal support and oral muscle-related factors (e.g., TP, ODK, MMT) are associated with MCI in older adult. These findings suggest that tailored interventions, including muscle training and posterior occlusal rehabilitation, could mitigate declines in cognitive functions associated with MCI in older adult.