Tachimura T, Nohara K, Fujita Y, Hara H, Wada T
Division for Oral and Facial Disorders, Graduate School of Dentistry, Osaka University, 1-8 Yamada-Oka, Suita, Osaka, 565-0871 Japan.
Cleft Palate Craniofac J. 2001 Sep;38(5):449-54. doi: 10.1597/1545-1569_2001_038_0449_cilvpm_2.0.co_2.
The purpose of this study was to examine whether mechanical elevation of the velum can directly affect the levator veli palatini muscle (LVP) activity using normal speakers as subjects.
Each subject was instructed to produce /mu/, /u/, /pu/, /su/, and /tsu/ in a speech task and to blow with maximum possible effort. Smoothed electromyographic activity of the LVP was recorded with an experimental palatal lift prosthesis (PLP) both in place and removed.
Four normal speakers were used as subjects.
LVP activity for all tasks was significantly smaller (p <.001; Student's t test) with the PLP in place than without the PLP for all subjects. An analysis of variance (p <.001) clarified that activity ranges of the LVP were significantly different between the removal and placement conditions for all the subjects.
The result was similar to that previously obtained for patients with velopharyngeal incompetence wearing a PLP. It is possible that the decrease in the LVP activity in association with placement of a PLP is caused by the direct effect of mechanical elevation, which decreases the distance the velopharyngeal mechanisms must travel for complete closure of the velopharynx.
本研究旨在以正常说话者为受试者，探讨软腭的机械抬高是否能直接影响腭帆提肌（LVP）的活动。
要求每位受试者在言语任务中发出/mu/、/u/、/pu/、/su/和/tsu/，并尽可能用力吹气。在实验性腭提升假体（PLP）就位和移除的情况下，记录LVP的平滑肌电图活动。
四名正常说话者作为受试者。
对于所有受试者，PLP就位时所有任务的LVP活动均显著小于PLP移除时（p <.001；学生t检验）。方差分析（p <.001）表明，所有受试者在PLP移除和就位条件下，LVP的活动范围存在显著差异。
该结果与先前对佩戴PLP的腭咽功能不全患者的研究结果相似。PLP就位时LVP活动降低可能是由机械抬高的直接作用导致的，这缩短了腭咽机制完全关闭腭咽所需移动的距离。
