Radboudumc 3DLab The Netherlands, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.
Department of Oral and Maxillofacial Surgery, Radboud University Medical Center, Nijmegen, The Netherlands.
PLoS One. 2021 Jan 26;16(1):e0246196. doi: 10.1371/journal.pone.0246196. eCollection 2021.
Orthognathic surgery is a widely performed procedure to correct dentofacial deformities. Virtual treatment planning is an important preparation step. One advantage of the use of virtual treatment planning is the possibility to assess the accuracy of orthognathic surgery. In this study, a tool (OrthoGnathicAnalyser 2.0), which allows for quantification of the accuracy of orthognathic surgery, is presented and validated. In the OrthoGnathicAnalyser 2.0 the accuracy of the osseous chin can now be assessed which was not possible in the earlier version of the OrthoGnathicAnalyser. 30 patients who underwent bimaxillary surgery in combination with a genioplasty were selected from three different centers in the Netherlands. A pre-operative (CB)CT scan, virtual treatment planning and postoperative (CB)CT scan were required for assessing the accuracy of bimaxillary surgery. The preoperative and postoperative (CB)CT scans were aligned using voxel-based matching. Furthermore, voxel-based matching was used to align the pre-operative maxilla, mandible and rami towards their postoperative position whereas surface-based matching was used for aligning the pre-operative chin towards the postoperative position. The alignment resulted in a transformation matrix which contained the achieved translations and rotations. The achieved translations and rotations can be compared to planning values of the virtual treatment plan. To study the reproducibility, two independent observers processed all 30 patients to assess the inter-observer variability. One observer processed the patients twice to assess the intra-observer variability. Both the intra- and inter-observer variability showed high ICC values (> 0.92) and low measurement variations (< 0.673±0.684mm and < 0.654±0.824°). The results of this study show that the OrthoGnathicAnalyser 2.0 has an excellent reproducibility for quantification of skeletal movements between two (CB)CT scans.
正颌手术是一种广泛用于矫正牙颌面畸形的手术。虚拟治疗计划是一个重要的准备步骤。使用虚拟治疗计划的一个优点是可以评估正颌手术的准确性。本研究介绍并验证了一种工具（OrthoGnathicAnalyser 2.0），它可以量化正颌手术的准确性。在 OrthoGnathicAnalyser 2.0 中，现在可以评估骨性颏部的准确性，而在早期版本的 OrthoGnathicAnalyser 中则无法做到这一点。从荷兰的三个不同中心选择了 30 名接受双颌手术联合颏成形术的患者。为了评估双颌手术的准确性，需要进行术前（CB）CT 扫描、虚拟治疗计划和术后（CB）CT 扫描。使用基于体素的配准对术前和术后（CB）CT 扫描进行配准。此外，还使用基于体素的配准将术前上颌、下颌和支骨对准术后位置，而使用基于表面的配准将术前颏对准术后位置。配准得到的转换矩阵包含了实际的平移和旋转。可以将实际的平移和旋转与虚拟治疗计划的规划值进行比较。为了研究可重复性，两位独立观察者处理了所有 30 名患者，以评估观察者间的变异性。一位观察者对患者进行了两次处理，以评估观察者内的变异性。观察者内和观察者间的变异性均显示出高 ICC 值（>0.92）和低测量变化（<0.673±0.684mm 和 <0.654±0.824°）。本研究结果表明，OrthoGnathicAnalyser 2.0 具有极好的可重复性，可用于量化两次（CB）CT 扫描之间的骨骼运动。
