Department of Computer and Information Science, Faculty of Science and Technology, University of Macau, Macau, China.
Department of Computer Science and Engineering, The Chinese University of Hong Kong, Shatin N.T., Hong Kong, China.
Int J Comput Assist Radiol Surg. 2017 Apr;12(4):595-606. doi: 10.1007/s11548-016-1475-3. Epub 2016 Sep 6.
The surgical treatment of many dentofacial deformities is often complex due to its three-dimensional nature. To determine the dental occlusion in the most stable position is essential for the success of the treatment. Computer-aided virtual planning on individualized patient-specific 3D model can help formulate the surgical plan and predict the surgical change. However, in current computer-aided planning systems, it is not possible to determine the dental occlusion of the digital models in the intuitive way during virtual surgical planning because of absence of haptic feedback. In this paper, a physically based haptic simulation framework is proposed, which can provide surgeons with the intuitive haptic feedback to determine the dental occlusion of the digital models in their most stable position.
To provide the physically realistic force feedback when the dental models contact each other during the searching process, the contact model is proposed to describe the dynamic and collision properties of the dental models during the alignment. The simulated impulse/contact-based forces are integrated into the unified simulation framework.
A validation study has been conducted on fifteen sets of virtual dental models chosen at random and covering a wide range of the dental relationships found clinically. The dental occlusions obtained by an expert were employed as a benchmark to compare the virtual occlusion results. The mean translational and angular deviations of the virtual occlusion results from the benchmark were small.
The experimental results show the validity of our method. The simulated forces can provide valuable insights to determine the virtual dental occlusion. The findings of this work and the validation of proposed concept lead the way for full virtual surgical planning on patient-specific virtual models allowing fully customized treatment plans for the surgical correction of dentofacial deformities.
由于其三维性质，许多牙颌面畸形的手术治疗往往很复杂。确定牙齿咬合在最稳定的位置对于治疗的成功至关重要。基于个体化患者特定 3D 模型的计算机辅助虚拟规划有助于制定手术计划并预测手术变化。然而，在当前的计算机辅助规划系统中，由于缺乏触觉反馈，无法在虚拟手术规划中直观地确定数字模型的牙齿咬合。在本文中，提出了一种基于物理的触觉模拟框架，可以为外科医生提供直观的触觉反馈，以确定数字模型在最稳定位置的牙齿咬合。
为了在搜索过程中牙齿模型相互接触时提供物理逼真的力反馈，提出了接触模型来描述牙齿模型的动态和碰撞特性在对准过程中。模拟的脉冲/基于接触的力被集成到统一的模拟框架中。
对随机选择的十五组虚拟牙齿模型进行了验证研究，涵盖了临床上发现的广泛的牙齿关系。专家获得的牙齿咬合被用作基准来比较虚拟咬合结果。虚拟咬合结果与基准的平均平移和角度偏差较小。
实验结果表明了我们方法的有效性。模拟力可以提供确定虚拟牙齿咬合的有价值的见解。这项工作的结果和提出的概念的验证为基于患者特定虚拟模型的全虚拟手术规划铺平了道路，允许为牙颌面畸形的手术矫正制定完全定制的治疗计划。
