目的：本研究旨在比较Vanbeek Activator, Herbst, Twin-Block和带下颌前导功能的隐形矫治器（MA）应用于骨性II类错颌畸形患儿的牙-骨效应。

方法：本研究共纳入63名患者（37名男性，26名女性），并将其分为未经治疗的对照组（C组，12名）、Vanbeek Activator组（V组，14名）、Herbst组（H组，11名）、Twin-Block组（TB组，12名）和MA组（14名）。通过头影测量和Johnston Pitchfork分析以量化磨牙、前牙关系矫正中的牙-骨效应各自占比，并比较组间头影测量数据和Johnston分析法数据的差异。

结果：治疗后，SNB、FH-NP、NA-PA、Co-Go、Co-Pog、ANB、下面高比、U1-PP、U6-PP、L1-MP和U1-L1数值均表现出显著差异。所有矫治器均显著改善了前牙覆盖（Vanbeek、Herbst、Twin Block和MA分别为2.77mm、5.53mm、4.73mm和3.66mm），上颌切牙内收明显。V组和MA组的下切牙内收，而H组和TB组的下切牙唇向倾斜，差异有统计学意义。Vanbeek、Herbst、Twin Block和MA的磨牙关系改善量分别为3.45mm、6.85mm、3.48mm和0.92mm，下颌位移量呈现出H组＞TB组＞V组＞MA组的趋势。H组上颌磨牙移位量大于C、TB、MA组，下颌磨牙移位量显著大于C、V、MA组。Herbst、Twin Block和MA比Vanbeek具有更显著的牙效应，而Vanbeek在抑制上颌生长方面的骨效应更明显。

结论：四种矫治器在前导下颌、矫正Ⅱ类磨牙关系和前牙深覆盖方面都很有效，但不可避免地会增加下面部比例。其中，Vanbeek Activator骨效应占比最高。Vanbeek和MA对下切牙角度有良好的控制作用，而Herbst和Twin Block的代偿性下切牙唇倾作用更强。Herbst具有远移动上颌磨牙的作用。MA的优势在于能够实现前导下颌的同时进行牙列的排齐和整平，且其中骨性效应占比为48.91%。

Background: The study aimed to compare the dentoskeletal effects of Vanbeek Activator, Herbst, Twin-Block and Mandibular Advancement with clear aligners in children with skeletal Class II malocclusions. 

Methods: A sample with sixty-three patients (37 males, 26 females) was included and divided into untreated control group (C, n=12), Vanbeek Activator group (V, n=14), Herbst group (H, n=11), Twin-Block group (TB, n=12) and MA group (MA, n=14). Cephalometric analysis and Johnston Pitchfork analysis were performed to quantify the skeletal and dentoalveolar components in molar relationship and overjet correction. Compare the differences of cephalometric data and Johnston-analysis data. 

Results: The treatment changes showed significant differences in SNB, FH-NP, NA-PA, Co-Go, Co-Pog, ANB, lower facial height ratio, U1-PP, U6-PP, L1-MP and U1-L1. All the appliances improved overjet relationships significantly (Vanbeek, Herbst, Twin-Block and MA were 2.77mm, 5.53mm, 4.73mm and 3.66mm respectively) with significant retraction of maxillary incisors. The lower incisor displacement of group V and MA was negative, while that of group H and TB was positive and there were significant differences. Molar relationships were also improved by 3.45mm, 6.85mm, 3.48mm and 0.92mm for Vanbeek, Herbst, Twin-Block and MA. Mandible displacement showed a trend of group H>TB>V>MA. The displacement of maxillary molars in group H was greater than that in group C, TB and MA, and that of mandibular ones was greater than that in group C, V and MA, significantly. Herbst, Twin-Block and MA have more significant dentoalveolar effect than Vanbeek, while Vanbeek has more skeletal effect than the others especially in restraining maxillary growth.

Conclusions: Four appliances are all effective in mandibular advancement, modification of class II molar relationship and deep overjet, with unavoidable increase in lower facial ratio. Vanbeek Activator has the most skeletal effects. Vanbeek and MA have a good control of mandibular incisors while more compensatory lower incisors proclination in Herbst and Twin-Block. Herbst has greater maxillary molar distalization. MA allows aligning and leveling meanwhile leading the mandible forward.