Effects of resistive jaw opening exercise in stroke patients with dysphagia: A double- blind, randomized controlled study.

Background: The resistive jaw opening exercise (RJOE) was suggested as a potential remedial treatment for patients with dysphagia. However, clinical evidence is insufficient.

Objective: To investigate the effect of RJOE on hyoid bone movement, aspiration, and oral intake level in stroke patients with dysphagia.

Methods: Forty stroke patients with dysphagia were randomly allocated into either the experimental group (n= 20) or placebo group (n= 20). The experimental group performed RJOE using a portable device, while the placebo group performed RJOE using a sham device with fewer loads. Intervention was conducted 5 times a week for 4 weeks. Hyoid bone movement was analyzed by two-dimensional analysis of anterior and superior motion based on a videofluoroscopic swallowing study. Aspiration was assessed using a penetration-aspiration scale (PAS), and oral intake level was assessed using the functional oral intake scale (FOIS).

Results: Both groups showed statistically significant differences in hyoid movement, PAS, and FOIS scale (p< 0.05). However, after the intervention, there was no significant difference between the two groups except for the liquid type of PAS. Effect sizes (Cohen's d) were 0.9 and 0.7, 0.6 and 0.6, and 1.1 for the anterior and superior movement of the hyoid bone, semisolid and liquid type of PAS, and FOIS scale respectively.

Conclusions: This study suggests that RJOE helps in hyoid movement, aspiration reduction, and oral intake in patients with dysphagia after stroke.