QUANTITATIVE ASSESSMENT OF HYOID BONE DISPLACEMENT FROM VIDEO IMAGES DURING SWALLOWING

Given the relationship between hyoid displacement and aspiration, a si mple, accurate, clinically useful method for identification of reduced hyoid displacement is needed. The purpose of this investigation was t o validate a quantitative method for clinically assessing hyoid bone m ovement during swallowing. Videofluoroscopic evaluations of 20 male su bjects--10 who had been subjectively assessed as demonstrating normal hyoid displacement during swallowing, and 10 who had been subjectively assessed as demonstrating reduced displacement during swallowing--wer e analyzed. A video measuring gauge was used, and a software spreadshe et was developed to perform trigonometric calculations for determinati on of anterior/superior hyoid trajectories. Statistically significant differences were found between groups in both the anterior and superio r directions of hyoid movement. No significant differences were found between liquid and paste swallows within groups. This method is simple in that it is necessary to identify only three to five points on two video images. Those values are then input onto a preprogrammed spreads heet that automatically performs the necessary calculations. Although the present investigation focused on the movements of the hyoid bone d uring swallowing, this method of tracking displacement can be used for virtually any task or structure whose movements can be captured on vi deotape.