Oral Factors Associated With Declines in Masticatory and Swallowing Function in Older and Middle-Aged Dental...

Frailty prevention is essential in older adults, as oral frailty and hypofunction are linked to increased risks of physical frailty, dependency and mortality. Declines in integrated oral functions, particularly mastication and swallowing, can reduce dietary diversity, impair nutrition and accelerate frailty progression. Although oral hypofunction tests are used for screening and management, the underlying mechanisms and priorities for targeted interventions remain unclear.

To investigate the associations between declines in masticatory and swallowing functions and specific oral functional impairments among dental outpatients.

In this cross-sectional study, we included 204 outpatients aged ≥ 50 years (mean age: 77.1 ± 8.5 years) who underwent oral hypofunction tests for the first time. Data were collected on systemic health and seven oral function domains: oral hygiene, oral dryness, occlusal force, tongue-lip motor function, tongue pressure, masticatory function and swallowing function. Pearson's correlation and multiple linear regression analyses were conducted, adjusting for age, sex and comorbidities.

Masticatory function decline was significantly associated with reduced occlusal force and posterior tongue-lip motor function. Swallowing function decline was significantly associated with reduced tongue pressure and anterior tongue-lip motor function.

Masticatory and swallowing functions are closely linked to occlusal force, tongue strength and tongue motor function. These findings highlight the need for targeted oral function training, especially of the tongue and occlusal system, to maintain dietary intake and support frailty prevention in older adults.