Objectives

We aimed to quantify the displacement of the proximal segment after bilateral sagittal split osteotomy in patients with class III asymmetry and evaluate if the displacement was related to the movement of the distal segment.

Material and methods

Forty adults with class III asymmetry corrected by bimaxillary surgery were studied. Cone-beam computed tomography taken before and 1 week after surgery was used to measure the displacement of proximal segments and movement of the distal segment in terms of translation and rotation. The relationship between the displacemnt of the proximal segment and the movement of the distal segment was evaluated.

Results

After surgery, the deviated proximal segment was displaced forward and to the deviated side, rotated downward, tilted, and turned to the opposite side. The opposite proximal segment was displaced forward and rotated downward. The roll rotation of the proximal segment was correlated with the left/right movement and roll rotation of the distal segment.

Conclusion

Early after orthognathic correction for class III asymmetry, the deviated proximal segment was displaced in a direction favorable for correction of asymmetry. The roll rotation of the proximal segment was affected by the transverse movement and roll rotation of the distal segment.

Clinical relevance

Knowledge of the ability and limitation of the proximal segment rotation improves the virtual simulation.

中文翻译：

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对于III类不对称性，双侧矢状劈开截骨术后近端节段位移的新3D分析。

目标

我们的目的是量化三级不对称患者双侧矢状劈开截骨术后近端节段的位移，并评估位移是否与远端节段的运动有关。

材料与方法

研究了四十名通过双颌手术矫正的III级不对称成年人。术前和术后1周进行的锥形束计算机体层摄影术以平移和旋转的方式测量近端节段的位移和远端节段的运动。评价了近端节段的位移与远端节段的运动之间的关系。

结果

手术后，偏斜的近端节段向前移位至偏斜的一侧，向下旋转，倾斜并转向相反的一侧。相对的近端节段向前移位并向下旋转。近端部分的侧倾旋转与远端部分的左/右运动和侧倾旋转相关。

结论

在正颌矫正III类不对称后的早期，偏斜的近端节段朝着有利于纠正不对称的方向移位。近端部分的侧倾旋转受远端部分的横向运动和侧倾旋转影响。

临床相关性

了解近端节段旋转的能力和局限性改善了虚拟仿真。