[To study the correlation between hyoid movement and openness of upper esophageal sphincter]

To discuss the effect of age on hyoid movement and the openness of UES in swallowing process, and to investigate the correlation between hyoid movement and openness of UES.

The X-ray dynamic swallowing videofluoroscopy was performed on 100 healthy adult volunteers(20-74 years). They were divided into three groups: young (ages 20 to 45), middle-aged (45 to 65) and older (65 and up). Then the software Avidemux 2. 5 and Image J were used to measure the time and distance of hyoid movement, and the maximal opening of the UES in swallowing process.

The time of hyoid moving to the maximal displacement was delayed along with the ages, and there were significant differences among the three groups (P<. 05). The staying time of hyoid in the maximal displacement gradually shortened along with the ages, and there was significant difference between young and older group, so was the middle-aged and older group(P<0. 05). The maximum antedisplacement of hyoid decreased with age, and significant differences were found between young and the middle-aged group and between oung and older group (P<0. 05). The maximal degree of UES opening decreased with the increase of age, and significant difference was found between young and older group (P<0. 05). The upper displacement of hyoid was not related to UES opening(P>0. 05), however, the antedisplacement of hyoid had significant relation to UES opening in the three groups (P<0. 05).

In swallowing process, the time and space parameters of hyoid movement and the maximal degree of UES opening were related to age. There was significant difference between the antedisplacement of hyoid and the openness of UES (P<0. 05).