van Baar Gustaaf J C, Liberton Niels P T J, Winters Henri A H, Leeuwrik Lars, Forouzanfar Tymour, Leusink Frank K J
Department of Oral and Maxillofacial Surgery/Pathology, Amsterdam UMC and Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam;
Medical Technology, 3D Innovation Lab, Amsterdam UMC, Vrije Universiteit Amsterdam.
J Vis Exp. 2020 Jan 28(155). doi: 10.3791/60363.
Valid comparisons of postoperative accuracy results in computer-assisted reconstruction of the mandible are difficult due to heterogeneity in imaging modalities, mandibular defect classification, and evaluation methodologies between studies. This guideline uses a step-by-step approach guiding the process of imaging, classification of mandibular defects and volume assessment of three-dimensional (3D) models, after which a legitimized quantitative accuracy evaluation method can be performed between the postoperative clinical situation and the preoperative virtual plan. The condyles and the vertical and horizontal corners of the mandible are used as bony landmarks to define virtual lines in the computer-assisted surgery (CAS) software. Between these lines the axial, coronal, and both sagittal mandibular angles are calculated on both pre- and postoperative 3D models of the (neo)mandible and subsequently the deviations are calculated. By superimposing the postoperative 3D model to the preoperative virtually planned 3D model, which is fixed to the XYZ axis, the deviation between pre- and postoperative virtually planned dental implant positions can be calculated. This protocol continues and specifies an earlier publication of this evaluation guideline.
由于各研究之间在成像方式、下颌骨缺损分类以及评估方法上存在异质性，因此很难对计算机辅助下颌骨重建术后的准确性结果进行有效的比较。本指南采用循序渐进的方法，指导成像过程、下颌骨缺损分类以及三维（3D）模型的体积评估，在此之后，可以在术后临床情况与术前虚拟计划之间进行合理的定量准确性评估。髁突以及下颌骨的垂直和水平角用作骨性标志，以在计算机辅助手术（CAS）软件中定义虚拟线。在这些线之间，在（新）下颌骨的术前和术后3D模型上计算轴向、冠状和两个矢状下颌角，随后计算偏差。通过将术后3D模型叠加到固定在XYZ轴上的术前虚拟计划3D模型上，可以计算术前和术后虚拟计划牙种植体位置之间的偏差。本方案延续并细化了该评估指南的早期出版物。
