Ulusoy Ilkay, Akagunduz Erdem, Sabuncuoglu Fidan, Gorgulu Serkan, Ucok Ozlem
Dept. of Electrical and Electronics Eng., Middle East Technical University, Ankara, Turkey.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010 Nov;110(5):e17-23. doi: 10.1016/j.tripleo.2010.06.004.
The shape of the face can be estimated before the surgery by using 3-dimensional computer programs that provide tools to guide skill modifications. The aim of this study was to present the dynamic volume spline method to predict facial soft tissue changes after the modification of the skull associated with orthognathic surgery.
Soft tissue volume is modeled by a dynamic volume spline that includes the elastic behavior of the actual tissue. The model is a hybrid of spring-mass model and finite element model, and combines their advantageous properties. It provides fast and realistic soft tissue simulations. Postsurgical shape of the patient's face is estimated by reshaping the skull and letting the soft tissue model relax over the new boundary conditions formed by the new skull shape. Postsurgical estimations were compared with the conventional method's estimations, where the soft tissue is not modeled biomechanically. Also, postsurgical estimations were compared with the actual postsurgical data for 6 orthognathic surgery patients.
The mean of the error between the estimated shapes and the actual postsurgical shapes was ∼1.8 mm when the whole face was considered.
When the facial soft tissue is modeled by the dynamic volume spline, the postsurgical shape is estimated better than by the conventional method and previous methods in the literature.
术前可通过使用三维计算机程序估计面部形状，该程序提供了指导手术技巧调整的工具。本研究的目的是介绍动态体积样条法，以预测正颌外科手术相关颅骨改建后面部软组织的变化。
软组织体积由包含实际组织弹性行为的动态体积样条建模。该模型是弹簧-质量模型和有限元模型的混合体，结合了它们的优势特性。它提供快速且逼真的软组织模拟。通过重塑颅骨并让软组织模型在由新颅骨形状形成的新边界条件下松弛，来估计患者术后的面部形状。将术后估计结果与传统方法的估计结果进行比较，传统方法中软组织未进行生物力学建模。此外，还将术后估计结果与6例正颌手术患者的实际术后数据进行比较。
当考虑整个面部时，估计形状与实际术后形状之间的误差均值约为1.8毫米。
当用动态体积样条对面部软组织进行建模时，术后形状的估计比传统方法和文献中的先前方法更好。
