Relationship between eating/swallowing function and respiration mode in children with habit-forming mouth breathing

本研究旨在探讨儿童习惯性口呼吸对咀嚼和姿势的影响，以五名健康成人为研究对象，在捏鼻模拟鼻塞的条件下进行初步研究。采用表面电极技术采集咬肌、眼轮匝肌、胸锁乳突肌和喉周肌的肌电图。用呼吸机电传感器测得呼吸曲线。肌电图与呼吸曲线同步。在休息和咀嚼酸奶或饼干期间检查鼻塞的影响。获得了以下结果。鼻塞下呼吸周期紊乱，吞咽前后呼吸周期延长，吞咽后呼吸曲线振幅下降。与以往的研究结果一致，在鼻阻塞状态下，咀嚼频率降低。另一方面，咬肌肌电的周期、间隔、持续时间也因受试者不同而呈现不同的模式。认为在模拟鼻阻塞条件下，存在基于获得的自身正常功能的代偿效应。研究对象在进食饼干时的呼吸模式、嘴唇姿势和咀嚼频率。用带鼻适配器的CO2传感器套件测定PaCO 2是评价呼吸模式的简便有效的方法。习惯性张口呼吸组儿童在吃饼干过程中张口率低，呼吸节律紊乱，PaCO 2曲线移动不规则。安静时张口，但在指示下可以通过鼻子呼吸的儿童在吃饼干时呼吸正常。需要进一步研究口呼吸器中进食/吞咽功能与呼吸的协同作用。

The purpose of this study is to investigate how habit-forming mouth breathing in children influences on mastication and posture.The subjects of preliminary study were five healthy adults under the condition of nose obstruction simulated by pinching the nose. Electromyograms (EMG) were obtained from masseter muscle, orbicularis orbis muscle, stenocleidomastoid muscle, and muscles around larynx using a surface electrode technique. Respiratory curves were obtained with amechano-electrical transducer for respiration. The EMGs and respiratory curve were synchronized. The effects of nose obstruction were examined during resting and masticating yogurt or cookie. Following results were obtained. Under the nose obstruction, disorder of respiration cycles, prolonged respiration cycle before and after swallowing, decrease of amplitude of respiration curve just after swallowing. As the results in previous studies, frequency of mastication decreased under the nose obstruction. The other hand, cycle, interval, duration of EMG of the masseter muscle showed various patters depend on the subjects. It was thought that compensatory effects based on acquired own normal function were occurred under the simulated nose obstruction.Children with oral breathing were elected using CO2 sensor kit. The subjects were evaluated respiration mode and recorded posture of lips and frequency of mastication during eating cookie. Measuring PaCO2 by the CO2 sensor kit with nasal adapter was convenient and useful method for evaluating respiration mode. The children classified into habit-forming mouth breather showed quite low rate of mouth closure, disorder of respiration rhythm, and irregular movement of PaCO2 curve during eating cookie. The children who held mouth open at rest but could breathe through the nose under indication showed regular respiration during eating cookie. Further study regarding eating/swallowing function in cooperation with respiration in mouth breathers is needed.