Relationship between the developmental variation in tongue function with open-bite and the articulatory disorder

本研究旨在通过明确舌位和发音特点来发展前张开咬合儿童舌位问题的口腔功能。每个受试者都被要求说出短句《Hana ga saita》，并用语音声学分析比较了张开咬合和正常咬合儿童所有被记录的声音。用声谱图和共振峰历史来表示整个声音波形。提取清音肺泡摩擦音/S/的共振峰频率(F1、F2、F4)。由于F4被认为反映了说话者的声道长度，因此F1和F2都被F4除以，以便相对评估它们。开放咬合组F1、F2频率显著高于正常咬合组。结果表明，在开放咬合患者中，牙槽骨变为牙间，摩擦力变为近似值。首先，在吞咽阶段观察到舌背中央沟形成的正常发育过程。将20名女性按牙期分为4组，用B+M模式观察其饮水时舌头在左右上颌第一磨牙连线上的移动情况。结果表明，中央沟形成成熟的时间为混合牙期的早期。此外，为了了解不同咬合组在静止状态下舌位的特点，分析了舌背的B超矢状位图像。讨论了舌背弯(CTD)与覆牙合的关系。结果表明，舌位对前切牙关系有影响，张开咬合儿童舌背较平。

This study intended to develop the oral function of children who had the problem in tongue posture with anterior open bite by clarifying both their tongue positions and the articulation characteristics. Each examinee was asked to say the short sentence "Hana ga Saita", and all the recorded sound was compared between open bite and normal bite children using the acoustic analysis of speech. The whole sound-waveform was expressed by both the sound-spectrogram and the formant history. The formant frequencies (F1, F2, F4) of voiceless alveolar fricative sound /s/ were extracted. As F4 is supposed to reflect the length of a talker's vocal tract, both F1 and F2 were divided by F4 in order to evaluate them relatively. The frequencies of F1 and F2 in patients with open bite were significantly higher than those in patients with normal bite. It is suggested that in patients with open bite the alveolar became an interdental, the fricative became an approximant.Tongue postures were analyzed by the ultra-sonography. First, normal developmental process in the central groove formation on tongue dorsum was observed at oral swallowing stage. 20 females were divided into four groups according to their dental stages, their tongue movement at the line connecting the left and right upper first molars while drinking water was observed by B+M Mode. The results suggested that the time at when the central groove formation became mature was the early mixed dentition period. Furthermore, to find the characteristics of the tongue posture in rest position among different occlusal groups, B Mode sagittal images of the tongue dorsum were analyzed. The correlation between the curvature of tongue dorsum (CTD) and the over-bite was discussed. The results showed that the tongue posture in rest position influenced the anterior incisor relationship and the tongue dorsum of open bite children was relatively flat.