Hirai T, Tanaka O, Koshino H, Takasaki H, Hashikawa Y, Yajima T, Matai N
Nihon Hotetsu Shika Gakkai Zasshi. 1989 Apr;33(2):457-65. doi: 10.2186/jjps.33.457.
In order to investigate tongue skill, upward and downward tongue movements with two constant frequencies were observed by using an ultrasound system in young and elderly adults. Upward and downward movements in accordance with a metronome were recorded by ultrasound recorder from the Motion-mode. Movement rhythm and movement velocity of the tongue were compared in the two age groups. The main findings were: 1. The ultrasound system with 5 MHz ultrasound convex transducer and Motion-mode observation produced clear traces of the tongue surfaces in the sagital plane during upward and downward movements. 2. Upward and downward movement rhythms in the elderly were more irregular than those of young adults. 3. Velocity of tongue upward and downward movements were statistically decreased in the elderly (p less than 0.01). Velocity did not clearly change if the movement speed was different in the elderly. Results of this study revealed that oral motor behaviour in the elderly differed from that of young adults.
