Liebregts Jeroen H F, Timmermans Maarten, De Koning Martien J J, Bergé Stefaan J, Maal Thomas J J
Resident, Department of Oral and Maxillofacial Surgery, Radboud University Medical Centre, Nijmegen, The Netherlands; and the Facial Imaging Research Group, Nijmegen and Bruges, Belgium.
OMF Surgeon, Department of Oral and Maxillofacial Surgery, Radboud University Medical Centre, Nijmegen, The Netherlands; and the Facial Imaging Research Group, Nijmegen and Bruges, Belgium.
J Oral Maxillofac Surg. 2015 May;73(5):961-70. doi: 10.1016/j.joms.2014.11.006. Epub 2014 Nov 20.
Three-dimensional (3D) virtual planning of orthognathic surgery in combination with 3D soft tissue simulation allows the surgeon and the patient to assess the 3D soft tissue simulation. This study was conducted to validate the predictability of the mass tensor model soft tissue simulation algorithm combined with cone-beam computed tomographic (CBCT) imaging for patients who underwent mandibular advancement using a bilateral sagittal split osteotomy (BSSO).
One hundred patients were treated with a BSSO according to the Hunsuck modification. The pre- and postoperative CBCT scans were matched and the mandible was segmented and aligned. The 3D distance maps and 3D cephalometric analyses were used to calculate the differences between the soft tissue simulation and the actual postoperative results. Other study variables were age, gender, and amount of mandibular advancement or rotation.
For the entire face, the mean absolute error was 0.9 ± 0.3 mm, the mean absolute 90th percentile was 1.9 mm, and for all 100 patients the absolute mean error was less than or equal to 2 mm. The subarea with the least accuracy was the lower lip area, with a mean absolute error of 1.2 ± 0.5 mm. No correlation could be found between the error of prediction and the amount of advancement or rotation of the mandible or age or gender of the patient.
Overall, the soft tissue prediction algorithm combined with CBCT imaging is an accurate model for predicting soft tissue changes after mandibular advancement. Future studies will focus on validating the mass tensor model soft tissue algorithm for bimaxillary surgery.
正颌外科的三维（3D）虚拟规划结合3D软组织模拟，可让外科医生和患者评估3D软组织模拟情况。本研究旨在验证质量张量模型软组织模拟算法结合锥形束计算机断层扫描（CBCT）成像对采用双侧矢状劈开截骨术（BSSO）进行下颌前徙的患者软组织变化的预测能力。
100例患者根据亨萨克改良法接受BSSO治疗。对术前和术后的CBCT扫描进行匹配，分割并对齐下颌骨。使用3D距离图和3D头影测量分析来计算软组织模拟与术后实际结果之间的差异。其他研究变量包括年龄、性别以及下颌前徙或旋转的量。
对于整个面部，平均绝对误差为0.9±0.3mm，平均绝对第90百分位数为1.9mm，100例患者的绝对平均误差均小于或等于2mm。准确性最低的分区是下唇区域，平均绝对误差为1.2±0.5mm。预测误差与下颌骨前徙或旋转的量、患者的年龄或性别之间未发现相关性。
总体而言，结合CBCT成像的软组织预测算法是预测下颌前徙后软组织变化的准确模型。未来的研究将集中于验证双颌手术的质量张量模型软组织算法。
