2008 Volume 12 Issue 2 Pages 135-140
【Purpose】To evaluate the hyoid bone dynamic phase of swallowing in normal subjects by ultrasonography.
【Subject and Methods】Date were obtained from 15 healthy volunteers (mean age：34.9±9.3), and the subjects were divided into three groups：5 subjects in their twenties, 5 in their thirties, and 5 in their forties. The subjects were examined sitting in the upright position, with their back resting against a wall to control movement. With the transducer placed in longitudinal scan above the larynx, the hyoid bone was located in the middle of the screen. The hyoid bone was identified on the scan as a high echoic area with posterior acoustic shadow. The subjects swallowed 5 ml of mineral water and measurements were taken 5 times. The images were analyzed by software (image J), and digital-ultrasonographic recordings were viewed at 30 frames/s for 3 seconds. Frozen frames of the moving image were analyzed, and range of movement of the hyoid bone from the resting point was measured (horizontal migration length, perpendicular migration length).
【Results】In this study, normal hyoid bone trajectory was easily visualized by ultrasonography. In all cases, the trajectory of the hyoid bone identified by ultrasonographic analysis was confirmed to be similar to that by videofluorography. Thus, ultrasonography can accurately determine the swallowing duration and trajectory of hyoid bone movement. Regarding the duration of measurements of 15 normal subjects, significant differences were found between the twenties group or thirties group and forties group (P＜0.05), but differences between the thirties group and forties group were not significant (P＝0.87).
【Conclusion】The results show that the dynamic phase image of the hyoid bone movement can be revealed by ultrasonographic visualization. Ultrasonography can be used for determining the position of the hyoid bone as a new technique for dysphagia, which may be useful in the diagnosis of swallowing disorders.