Ultrasonographic assessment of swallowing-related muscles
The cross-sectional area of the geniohyoid muscle (CSA of the GH) and the thickness of the tongue were evaluated using an ultrasonic measuring device (SonoSite M-turbo, Fujifilm, Tokyo, Japan) in B modeThe intraclass correlation coefficients (ICC) (1,1) and (2,1) were calculated to evaluate the reliability of the examiner. ICC (1,1) 0.925 and (2,1) 0.966 is used for measuring the CSA of the GH, and ICC (1,1) 0.936 and (2,1) 0.925 for the thickness of the tongue, which revealed high reliability. ImageJ software (National Institutes of Health, Bethesda, MD, USA) was used for image processing. The CSA of the GH and tongue thickness were measured thrice and twice, respectively, and the mean values were recorded. During the analysis, the examiner was blinded to the information, including the names of the participants and whether the image was taken at baseline or at follow-up.