Anterior subapical segmental osteotomy is considered to be an important surgical technique to obtain functional occlusion and improve the facial profile for patients with maxillary and mandibular protrusion or retrusion, and some complications, such as ischemic necrosis of the distal segment, devitalization of the teeth adjacent to the osteotomy site, and inadequate movement space of segment for obtaining a good occlusion or facial profile, usually exist during surgery. Imprecise measurement of root length, interradicular distance, and intertooth distance based on traditional panoramic radiography that demonstrated existing horizontal distortion and vertical distortion may play an important role in resulting in these problems. In addition, the root is invisible for surgical simulation in traditional plaster models. The recently developed cone-beam computed tomography (CBCT) presents a higher spatial resolution with a lower radiation dose, simultaneously with excellent accuracy and without magnification of images. The presented technique was used to obtain a precise occlusal splint in virtual 3D subapical segmental osteotomy by combining CBCT with plaster models that could guarantee the measurement accuracy of root length, interradicular distance, and intertooth distance, followed by the result of fewer tooth root damage and more precise forecasting of available movement space of jaw segment. Combining with other advantages of virtual 3D surgery, such as precise teeth surface of plaster models, soft tissue simulation, genoplasty simulation, and zygoma plasty simulation, this presented technique may offer a preferable method to patients who need subapical segmental osteotomy.

中文翻译：

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CBCT结合石膏模型：在虚拟三维根尖节段截骨术中的应用，以获得更精确的咬合夹板。

根尖下段截骨术被认为是获得功能性闭锁并改善上颌和下颌前突或后退以及某些并发症（例如远端节段缺血性坏死，邻近牙齿的失活）的患者的面部轮廓的重要外科手术技术。通常在手术过程中存在截骨部位，并且节段的运动空间不足以获得良好的咬合或面部轮廓。基于传统全景射线照相术的根长，根际距离和齿间距离的不精确测量结果表明，现有水平变形和垂直变形可能在导致这些问题中起着重要作用。另外，在传统石膏模型中，根部对于外科手术模拟是不可见的。最近开发的锥束计算机断层扫描（CBCT）具有更高的空间分辨率和更低的辐射剂量，同时具有出色的准确性，并且无需放大图像。通过将CBCT与石膏模型结合使用，该技术可在虚拟3D根尖下节段截骨术中获得精确的咬合夹板，从而保证牙根长度，根际距离和齿间距离的测量准确性，从而减少牙根损伤和颚部段可用运动空间的更精确预测。结合虚拟3D手术的其他优势，例如石膏模型的精确牙齿表面，软组织模拟，基因成形模拟和骨成形模拟，