Relationship Between Oral Motor and Cognitive Function in Community-Dwelling Korean Older Adults: A Cross-Sectional, Observational Study

Background: The present study analyzed the relationship between oral motor and cognitive functions in community-dwelling older Korean adults. Methods: Study participants included 113 community-dwelling older adults with a mean age of 73.84 years. Subjects’ cognition was assessed using the Korean version of the Montreal Cognitive Assessment, and tongue, cheek, and lip pressures were assessed using the Iowa Oral Performance Instrument. Tongue and masseter thicknesses were measured using an ultrasound device (Sonon, Healcerion, Roseville, CA, USA). The occlusal force was measured using a specialized device (Innobyte, Kube Innovation, Montreal, QC, Canada), and the number of lost teeth was directly verified by a dental hygienist. Results: Results of analysis of cognitive function according to demographic characteristics of older community-dwelling adults revealed a significant difference in cognitive function according to education level and employment status. Cognitive function demonstrated a positive correlation with oral motor function, including pressure on the cheek, lips, and tongue, thickness of the masseter and tongue, occlusal force, number of lost teeth, and age. Hierarchical regression analysis revealed that demographic characteristics and cheek, lip, tongue, and masseter functions did not affect cognition, whereas occlusal force and number of lost teeth significantly affected cognition. In this study, oral motor function, excluding occlusal force and number of lost teeth, did not affect cognition. Conclusions: Future studies, however, are required to analyze the relationship between oral motor function and cognition in older adults with a wider range of such functions.