Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, 6560 Fannin St, Houston, TX 77030, USA.
Department of Oral and Maxillofacial Surgery, Houston Methodist Research Institute, 6560 Fannin St, Houston, TX 77030, USA; Department of Surgery (Oral and Maxillofacial Surgery), Weill Medical College, Cornell University, 407 E 61st St, New York, NY 10065, USA.
Med Image Anal. 2021 Aug;72:102095. doi: 10.1016/j.media.2021.102095. Epub 2021 May 5.
Accurate prediction of facial soft-tissue changes following orthognathic surgery is crucial for surgical outcome improvement. We developed a novel incremental simulation approach using finite element method (FEM) with a realistic lip sliding effect to improve the prediction accuracy in the lip region. First, a lip-detailed mesh is generated based on accurately digitized lip surface points. Second, an improved facial soft-tissue change simulation method is developed by applying a lip sliding effect along with the mucosa sliding effect. Finally, the orthognathic surgery initiated soft-tissue change is simulated incrementally to facilitate a natural transition of the facial change and improve the effectiveness of the sliding effects. Our method was quantitatively validated using 35 retrospective clinical data sets by comparing it to the traditional FEM simulation method and the FEM simulation method with mucosa sliding effect only. The surface deviation error of our method showed significant improvement in the upper and lower lips over the other two prior methods. In addition, the evaluation results using our lip-shape analysis, which reflects clinician's qualitative evaluation, also proved significant improvement of the lip prediction accuracy of our method for the lower lip and both upper and lower lips as a whole compared to the other two methods. In conclusion, the prediction accuracy in the clinically critical region, i.e., the lips, significantly improved after applying incremental simulation with realistic lip sliding effect compared with the FEM simulation methods without the lip sliding effect.
准确预测正颌手术后的面部软组织变化对于改善手术效果至关重要。我们开发了一种使用有限元方法（FEM）的新型增量模拟方法，并具有逼真的唇滑动效果，以提高唇区域的预测准确性。首先，根据精确数字化的唇表面点生成详细的唇网格。其次，通过施加唇滑动效果以及黏膜滑动效果来开发改进的面部软组织变化模拟方法。最后，通过增量模拟正颌手术引发的软组织变化，促进面部变化的自然过渡并提高滑动效果的有效性。我们的方法通过与传统的 FEM 模拟方法和仅具有黏膜滑动效果的 FEM 模拟方法相比，使用 35 个回顾性临床数据集进行了定量验证。与其他两种方法相比，我们的方法在上下唇的表面偏差误差方面表现出显著改善。此外，使用我们的唇形分析进行的评估结果反映了临床医生的定性评估，也证明了与其他两种方法相比，我们的方法对下唇以及上下唇整体的唇预测准确性有了显著提高。总之，与没有唇滑动效果的 FEM 模拟方法相比，应用具有逼真唇滑动效果的增量模拟后，在临床上关键区域（即嘴唇）的预测准确性显著提高。
