Tachimura T, Nohara K, Hara H, Wada T
Division for Oral and Facial Disorders, Faculty of Dentistry, Osaka University, Suita, Japan.
Cleft Palate Craniofac J. 1999 May;36(3):224-32. doi: 10.1597/1545-1569_1999_036_0224_eopoas_2.3.co_2.
We have observed clinically that some speakers wearing a speech appliance for correction of velopharyngeal incompetence can blow with variable intensity without nasal air escape. This clinical finding suggests that tightness of velopharyngeal closure may be regulated in accordance with oral air pressure during blowing. The purposes of this electromyographic study were (1) to examine whether levator vell palatini muscle activity can be changed in relation to oral air pressure during blowing when the speech appliance is removed, (2) to clarify whether or not the change is related to the severity of velopharyngeal incompetence, and (3) to examine whether placement of a speech appliance can alter levator muscle activity into the equivalent of that of normal speakers during blowing.
Eight patients with repaired cleft palate, who routinely wear a palatal lift prosthesis (PLP) or a hybrid speech appliance of a pharyngeal bulb and palatal lift (bulb-PLP), served as subjects. Subjects were classified into one of two groups according to their speech appliance (PLP group and bulb-PLP group). Electromyography of the levator veli palatini muscle was recorded with a speech appliance in place and then with the speech appliance removed as the subject blew through a tube at three different effort levels.
In the removed condition, the change in levator activity in relation to oral air pressure was variable across subjects in the bulb-PLP group, whereas levator activity changed in relation to oral air pressure change for all subjects in the PLP group. However, levator activity changed in relation to oral air pressure with either speech appliance in place for all subjects irrespective of their speech appliance types.
The severity of velopharyngeal incompetence might be related in part to change in levator activity in association with oral air pressure. The effect of a speech appliance to correct velopharyngeal incompetence might consist not only of mechanical obturation of the velopharynx but also of alteration of velopharyngeal function to become similar to normal speakers. Moreover, it is likely that the velopharyngeal system could be well regulated so as to exhibit a consistent outcome of velopharyngeal function.
我们在临床上观察到，一些佩戴语音矫治器以纠正腭咽闭合不全的患者在吹气时能够以不同强度吹气且无鼻腔漏气。这一临床发现表明，腭咽闭合的紧密程度可能会根据吹气时的口腔气压进行调节。这项肌电图研究的目的是：（1）检查在移除语音矫治器后，吹气时腭帆提肌的活动是否会随着口腔气压的变化而改变；（2）阐明这种变化是否与腭咽闭合不全的严重程度有关；（3）检查佩戴语音矫治器是否能使吹气时腭帆提肌的活动改变为与正常说话者相当。
八名腭裂修复患者作为研究对象，他们常规佩戴腭托（PLP）或带有咽球和腭托的混合语音矫治器（咽球 - PLP）。根据所佩戴的语音矫治器将研究对象分为两组（PLP组和咽球 - PLP组）。在佩戴语音矫治器时以及移除语音矫治器后，让研究对象通过一根管子以三种不同的用力水平吹气，同时记录腭帆提肌的肌电图。
在移除语音矫治器的情况下，咽球 - PLP组中不同研究对象的腭帆提肌活动随口腔气压的变化情况各不相同，而PLP组中所有研究对象的腭帆提肌活动均随口腔气压变化而改变。然而，无论佩戴何种语音矫治器，所有研究对象在佩戴语音矫治器时，腭帆提肌活动均随口腔气压变化而改变。
腭咽闭合不全的严重程度可能部分与腭帆提肌活动随口腔气压的变化有关。语音矫治器纠正腭咽闭合不全的作用可能不仅包括对腭咽的机械性阻塞，还包括使腭咽功能改变为与正常说话者相似。此外，腭咽系统很可能能够得到良好调节，从而表现出一致的腭咽功能结果。
