Iwasaki T, Sato H, Suga H, Takemoto Y, Inada E, Saitoh I, Kakuno K, Kanomi R, Yamasaki Y
Department of Pediatric Dentistry, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima-City, Japan.
Division of Pediatric Dentistry, Graduate School of Medical and Dental Sciences, Niigata University, Niigata-City, Japan.
Orthod Craniofac Res. 2017 May;20(2):95-101. doi: 10.1111/ocr.12145.
To examine the influence of negative pressure of the pharyngeal airway on mandibular retraction during inspiration in children with nasal obstruction using the computational fluid dynamics (CFD) method.
Sixty-two children were divided into Classes I, II (mandibular retrusion) and III (mandibular protrusion) malocclusion groups.
Cone-beam computed tomography data were used to reconstruct three-dimensional shapes of the nasal and pharyngeal airways. Airflow pressure was simulated using CFD to calculate nasal resistance and pharyngeal airway pressure during inspiration and expiration.
Nasal resistance of the Class II group was significantly higher than that of the other two groups, and oropharyngeal airway inspiration pressure in the Class II (-247.64 Pa) group was larger than that in the Class I (-43.51 Pa) and Class III (-31.81 Pa) groups (P<.001). The oropharyngeal airway inspiration-expiration pressure difference in the Class II (-27.38 Pa) group was larger than that in the Class I (-5.17 Pa) and Class III (0.68 Pa) groups (P=.006).
Large negative inspiratory pharyngeal airway pressure due to nasal obstruction in children with Class II malocclusion may be related to their retrognathia.
采用计算流体动力学（CFD）方法研究鼻塞儿童吸气时咽气道负压对下颌后缩的影响。
62名儿童被分为安氏I类、II类（下颌后缩）和III类（下颌前突）错牙合畸形组。
使用锥形束计算机断层扫描数据重建鼻和咽气道的三维形状。采用CFD模拟气流压力，计算吸气和呼气时的鼻阻力和咽气道压力。
II类组的鼻阻力显著高于其他两组，II类组（-247.64 Pa）的口咽气道吸气压力大于I类组（-43.51 Pa）和III类组（-31.81 Pa）（P<0.001）。II类组（-27.38 Pa）的口咽气道吸气-呼气压力差大于I类组（-5.17 Pa）和III类组（0.68 Pa）（P=0.006）。
II类错牙合畸形儿童因鼻塞导致的较大吸气性咽气道负压可能与其下颌后缩有关。
