During virtual three-dimensional orthognathic surgery in cases where an overlap or penetrability occurs between the 2 jaws due to the repositioning of the maxillary segment, it is necessary to establish a vertical opening of the mandible to obtain a relatively good relationship with the maxillary segment for the fabrication of an intermediate occlusal splint. However, there are few reports that address the precise definition of the rotational axis of the mandible during virtual surgery. Here, we present the idea that the mandible's movement during virtual three-dimensional orthognathic surgery is similar to hinge movement in vivo and developed a method for locating the geometric center of the three-dimensional condyle using Hypermesh software combined with Mimics software. Subsequently, we defined the rotational axis of the mandible based on the located geometric centers of the bilateral condyles, and the mandible was then rotated around the defined axis from the retruded contact position to mimic the hinge movement. Preliminary results indicated that the presented method could approximately mimic the hinge movement of the mandible with a relatively high accuracy in a three-dimensional environment, which may improve the accuracy of virtual intermediate occlusal splint.

中文翻译：

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一种确定虚拟三维正颌手术中下颌骨潜在旋转轴的新方法。

在虚拟三维正颌外科手术中，由于上颌骨段的重新定位而导致两个颌骨之间出现重叠或穿透性，因此有必要建立下颌骨的垂直开口以获得与上颌骨段的相对良好的关系。中间咬合夹板的制造。但是，很少有报道涉及虚拟手术中下颌骨旋转轴的精确定义。在这里，我们提出了虚拟三维正颌外科手术中下颌骨的运动类似于体内铰链运动的想法，并开发了一种使用Hypermesh软件结合Mimics软件定位三维con骨几何中心的方法。后来，我们根据双侧dy的定位几何中心定义了下颌骨的旋转轴，然后将下颌骨从缩回的接触位置绕定义的轴旋转以模仿铰链运动。初步结果表明，所提出的方法可以在三维环境中以较高的精度近似模拟下颌骨的铰链运动，从而可以提高虚拟的中间咬合夹板的准确性。