Craniomaxillofacial reconstruction with patient-specific customized craniofacial implants (CCIs) is most commonly performed for large-sized skeletal defects. Because the exact size of skull resection may not be known prior to the surgery, in the single-stage cranioplasty, a large CCI is prefabricated and resized intraoperatively with a manual-cutting process provided by a surgeon. The manual resizing, however, may be inaccurate and significantly add to the operating time. This paper introduces a fast and non-contact approach for intraoperatively determining the exact contour of the skull resection and automatically resizing the implant to fit the resection area. Our approach includes four steps: First, a patient's defect information is acquired by a 3D scanner. Second, the scanned defect is aligned to the CCI by registering the scanned defect to the reconstructed CT model. Third, a cutting toolpath is generated from the contour of the scanned defect. Lastly, the large CCI is resized by a cutting robot to fit the resection area according to the given toolpath. To evaluate the resizing performance of our method, six different resection shapes were used in the cutting experiments. We compared the performance of our method to the performances of surgeon's manual resizing and an existing technique which collects the defect contour with an optical tracking system and projects the contour on the CCI to guide the manual modification. The results show that our proposed method improves the resizing accuracy by 56% compared to the surgeon's manual modification and 42% compared to the projection method.

翻译：由于在手术前,在单阶段的胸骨切片中,一个大型的胸骨切片的精确大小可能并不为人所知,因此大型的胸骨切片在手术前,在单阶段的胸骨切片中,一个大型的胸骨切片在手术中是预先制造的,并且用外科医生提供的人工切除过程在手术中进行了重新配置。然而,手册的重新缩放可能不准确,并大大增加了操作时间。本文件提出了一种快速和非接触的方法,用于在手术中确定头骨切片的准确轮廓,并自动调整胸口切片的准确性能以适应剖面区域。我们的方法包括四个步骤:首先,3D扫描器获得病人的缺陷信息。第二,扫描器的缺陷通过将扫描缺陷登记到经过改造的手动切片模型中,与CCI相匹配。第三,扫描器的轮廓是从扫描器的轮廓中生成的切片路径。最后,大型的 CCI由一个切片机器人重新缩到符合给定的剖面区域与给定的轮廓区域。我们使用的手动方法的变换方法比了我们目前使用的手动方法。我们使用的手动的手动方法的演图图图的缩方法,用来显示了我们的手动图图的缩方法。