Development of Therapeutic Procedure to Stimulate Velopharyngeal Function using Newly Designed Speech Appliance.

本研究的目的是建立一种策略，以刺激舌咽部功能，使用言语球减少。为了确定球的适当还原体积，当呼吸空气通过在语音器具球的垂直中心钻孔进入鼻腔时，监测与鼻气流速率和口腔气压变化相关的提提肌活动。开放面积从0（闭塞状态）到38.5mm^2到12.6mm^2不等。多元回归分析显示，提提肌活动与鼻空气流速和口腔气压相关，鼻空气流速对提提肌活动变化的影响比口腔气压更显著。在此基础上，设计了球囊复位治疗的原型策略，并将其应用于5例常规佩戴言语器具的腭裂修复患者。也就是说，灯泡体积的减小使灯泡体积的减小等于水平投影的圆形面积，范围从12.6mm^2到38.5mm^2。每月进行一次减量，持续3个月。每次复位后一个月进行鼻咽纤维镜和知觉评价。结果显示，5名受试者中有4名在说话时表现出腭咽完全闭合且无鼻分泌物，每次评估均观察到腭咽功能的改善。但另一名受试者在第一次和第二次评价中表现为完全闭合，而第三次评价没有任何改善。结果表明，这种球减少策略原型可能对改善腭咽功能有效，但改善腭咽功能的过程可能因受试者而异。还原效应的维持值得未来的研究。

The purpose of this study is to establish a strategy to stimulate velopharyngeal function using speech bulb reduction. To determine an adequate reduction volume of the bulb, levator muscle activity associated with changes in nasal air flow rate and oral air pressure was monitored when respiratory air was allowed into the nasal cavity through the opening drilled in the vertical center of the bulb of a speech appliance. The opening area was varied from 0 (occluded condition) to 38.5mm^2 through 12.6mm^2. Multiple regression analyzes showed that levator muscle activity correlated with nasal air flow rate and oral air pressure, while nasal air flow rate contributed to the changes in levator muscle activity more significantly than oral air pressure did. Based on the results, prototype strategy of bulb reduction therapy was designed and applied to 5 repaired cleft palate patients who were routinely wearing a speech appliance. That is, bulb reduction was performed so that decrease in the bulb volume could be equal to the circular area ranged from 12.6mm^2 to 38.5mm^2 in horizontal projection. The reduction was carried out monthly for 3 months. Nasopharyngeal fiberscopic and perceptual evaluations were carried out onemonth after each reduction. As results, four out of five subjects showed complete closure of the velopharynx and no nasal emission during obstruent speech, and the improved veloharyngeal function was observed in each evaluation. However, another subject showed complete closure in first and second evaluation, while third evaluation did not show any improvement. The results suggested that this prototype of bulb reduction strategy might be effective for the improvement of velopharyngeal function, while the process towards improved velopharyngeal function might be variable across subjects. A maintenance of the reduction effect warrants future study.