The aim of this study was to evaluate three-dimensional (3D) effects of Twin-block functional appliance (TB) on the pharyngeal airway by using cone beam computed tomography (CBCT). A total of 30 patients (14 females, 16 males; mean age and years, respectively) with skeletal Class II malocclusion were included in this study and were treated with TB. On the pretreatment (T1) and posttreatment (T2) CBCT scans, volumetric changes in the pharyngeal airway; SNA, SNB, and ANB angles; and bilateral effective mandibular (Co-Gn) and midfacial length (Co-A) were also evaluated. The statistical differences were accessed by Wilcoxon signed-rank tests, and Mann-Whitney tests were used to analyze the scores of male and female subjects. In this study, an increase was observed in SNB and Co-Gn () while a decrease in ANB and SNA ( and , respectively) was found. However, increase in midfacial length was not statistically significant (). In the evaluation of volumetric pharyngeal airway changes, statistically significant increases () in the upper and lower division and total airway volume were determined. Gender differences were insignificant for all measurements (). Volumetric changes in the pharyngeal airway after functional therapy can be successfully evaluated by CBCT images. The anterior repositioning of the mandible by TB increases the mandibular length and pharyngeal airway volume in patients with retrognathic mandible.

中文翻译：

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功能治疗后咽部气道的容积评估


本研究的目的是通过使用锥形束计算机断层扫描 (CBCT) 评估双块功能矫治器 (TB) 对咽部气道的三维 (3D) 影响。本研究共纳入 30 名骨性 II 类错牙合患者（14 名女性，16 名男性；分别为平均年龄和岁数），并接受 TB 治疗。治疗前 (T1) 和治疗后 (T2) CBCT 扫描，咽部气道容积变化； SNA、SNB 和 ANB 角度；还评估了双侧有效下颌（Co-Gn）和中面部长度（Co-A）。通过 Wilcoxon 符号秩检验得出统计差异，并使用 Mann-Whitney 检验来分析男性和女性受试者的分数。在这项研究中，观察到 SNB 和 Co-Gn 的增加（ ），同时 ANB 和 SNA 减少（和 ，分别）被发现。然而，中面部长度的增加并没有统计学意义（ ）。在评估咽部气道容积变化时，统计上显着增加（ ）在上、下分区和总气道容积被确定。所有测量结果的性别差异均不显着（ ）。功能治疗后咽部气道的体积变化可以通过 CBCT 图像成功评估。结核病导致下颌骨前移可增加下颌后缩患者的下颌长度和咽部气道容积。