Background: Timely and adequate laryngeal elevation along with hyoid bone movement is an essential component of the swallowing movement under normal physiological conditions. The purpose of this study was to verify the reproducibility of using ultrasonography to evaluate hyoid bone displacement during swallowing through the assessment of inter- and intrarater reliability and examine its accuracy by comparing the results with videofluoroscopic swallowing study (VFSS).
Methods: A self-designed water balloon was fixed to the transducer, which provided good contact between the transducer and the submental skin. Ten participants with dysphagia were recruited. The measurements of hyoid bone displacement using ultrasonography were performed by two of the authors. All the participants underwent ultrasonographic examinations and VFSS within 24 hours.
Results: The intrarater intraclass correlation coefficient (ICC) of the two examiners was 0.996 and 0.959, respectively (p < 0.01); the interrater ICC between the two examiners was 0.892 (p < 0.05). ICCs between VFSS and ultrasonography for two researchers were 0.815 and 0.916 (p < 0.01).
Conclusion: Submental ultrasonography is a reliable and accurate method for assessing the hyoid bone movement.
Keywords: dysphagia; hyoid bone; swallowing disorder; ultrasonography; ultrasound.