This study was aimed at proposing a three-dimensional (3D) evaluation method for the soft tissue effects of Twin Block (TB) functional appliance therapy by using cone beam computed tomography (CBCT) images. In this retrospective study, a total of 60 pre- and posttreatment (T0 and T1) CBCT images of Class II patients with mandibular retrognathia treated with a TB appliance were used. Volumetric and linear soft tissue changes were evaluated quantitatively with 3D measurements and qualitatively with color mapping visual. Linear (NV-A and NV-Pog) and angular (SNA, SNB, and ANB) skeletal changes were also measured on 3D images. The Wilcoxon signed-rank test was used to compare statistical differences, and the scores of male and female participant differences were observed with the Mann–Whitney test. In this study, a decrease was observed in SNA (), ANB (), and NV-Pog () while an increase in SNB () was found. However, decrease in NV-A distance was not statistically significant (). As a result of the evaluation of soft tissue changes, while the anterior reposition of the lower lip, soft tissue pogonion, and soft tissue gnathion was found to be significant (, , and , respectively), the upper lip and subnasale repositions were not statistically significant (). 3D soft tissue changes after TB therapy can be evaluated quantitatively and qualitatively by using CBCT images. Anterior repositioning of the mandible with functional therapy also provides improvement in soft tissue profile, especially in the lower facial region.

中文翻译：

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功能治疗后软组织变化的三维评价

本研究旨在提出一种利用锥形束计算机断层扫描 (CBCT) 图像对双块 (TB) 功能矫治器治疗的软组织效果进行三维 (3D) 评估的方法。在这项回顾性研究中，总共使用了 60 张治疗前后（T0 和 T1）的 CBCT 图像，这些图像是用 TB 矫治器治疗的下颌后缩的 II 类患者。体积和线性软组织变化通过 3D 测量进行定量评估，并通过颜色映射视觉进行定性评估。还在 3D 图像上测量了线性（NV-A 和 NV-Pog）和角度（SNA、SNB 和 ANB）骨骼变化。Wilcoxon 符号秩检验用于比较统计差异，并使用 Mann-Whitney 观察男性和女性参与者的分数差异测试。在这项研究中，观察到 SNA 下降（), ANB ()和 NV-Pog ()而瑞士央行的增加 ()被发现。然而，NV-A 距离的减少没有统计学意义（）。作为软组织变化的评估结果，发现下唇、软组织前突和软组织下颌前移是显着的（, ，和，分别），上唇和鼻下重新定位没有统计学意义（）。使用 CBCT 图像可以定量和定性地评估 TB 治疗后的 3D 软组织变化。使用功能疗法对下颌骨进行前路重新定位还可以改善软组织轮廓，尤其是在面部下部区域。