Oral health and its association with dysphagia severity and nutritional vulnerability after stroke: a structural equation modeling study

BACKGROUND: Oral health deterioration is common after neurological injury and may contribute to functional impairment beyond the oral cavity. In stroke rehabilitation, impaired oral conditions coexist with orofacial dysfunction and dysphagia, yet the mechanistic pathways linking oral health to swallowing impairment and downstream nutritional consequences remain poorly defined. This study examined the interrelationships between oral health, orofacial function, dysphagia, and malnutrition using structural equation modelling (SEM).

METHODS: Ninety-two stroke survivors admitted to a neurorehabilitation center underwent standardized assessments of oral health, orofacial function, dysphagia severity at admission, and nutritional screening at week 4. Oral health and orofacial function were modelled as latent variables. SEM was used to quantify pathways linking oral health to malnutrition risk, with bivariate comparisons stratified by dysphagia status.

RESULTS: Poor oral health was significantly associated with reduced orofacial function (β = -0.41, p < 0.001), which in turn was associated with dysphagia severity (β = -0.51, p < 0.001). Dysphagia showed a direct association with malnutrition risk (β = 0.31, p = 0.031). While poor oral health exerted a direct effect on malnutrition risk (β = 0.33, p = 0.023), the indirect pathway linking poor oral health to malnutrition through orofacial dysfunction and dysphagia was not statistically significant (β = 0.063, p = 0.091). The model identified a coherent oral-orofacial-swallowing pathway consistent with nutritional vulnerability after stroke.

CONCLUSION: These findings position oral health as an important factor associated with swallowing impairment and nutritional vulnerability after stroke within a modeled pathway. Integrating oral and orofacial assessments into post-stroke care may support earlier identification of patients at risk for functional decline and systemic complications.

CLINICAL SIGNIFICANCE: Oral health deterioration was associated with malnutrition risk after stroke, directly and via impaired orofacial function and dysphagia. Integrating oral and orofacial function measures into routine post-stroke assessments may improve early risk stratification and support coordinated dental and rehabilitation care.