Abstract
In previous study, we developed a jaw-opening sthenometer to assess the swallowing function and measured the jaw opening force of dysphagia patients. The aim of the present study is to validate the intra and inter reliabilities of a jaw-opening sthenometer for the jaw opening strength, using the interclass correlation coefficient (ICC). The raters were two dentists who made repeated measurements in 20 healthy volunteers as part of training prior to the present study. The eight healthy volunteers (mean age, 28.4±2.8 years; men, n＝5; women, n＝3) participated in the intra reliability study. Their jaw opening force was measured and then their ICC (1.1) was calculated. The ten healthy volunteers (mean age, 28.7±3.7 years; men, n＝6; women, n＝3) participated in the inter reliability study. Their jaw opening force was measured and then the ICC (2.1) was calculated. The ICC (1.1) was 0.96 and the ICC (2.1) was 0.94 in average data (measured twice). The jaw opening force is considered to reflect the strength of the suprahyoid muscles, and decreased jaw opening force can cause swallowing dysfunction resulting from decreased hyoid bone displacement. Therefore, measuring the jaw opening force is meaningful to assess the swallowing function. Since the jaw opening sthenometer showed high reliabilities, it could be useful muscle strength dyametar for assessing the swallowing function.
