title: Advances in collision detection and non-linear finite mixed element modelling for improved soft tissue simulation in craniomaxillofacial surgical planning.
abstract: BACKGROUND
  There is a huge demand to develop a method for assisting surgeons in automatically predicting soft tissue deformation in terms of a bone-remodelling plan.
  
  
  METHODS
  This paper introduces several novel elements into a system for the simulation of postoperative facial appearances with respect to prespecified bone-remodelling plans. First, a new algorithm for efficient detection of collisions, using the signed distance field, is described. Next, the penalty method is applied to determine the contact load of bone on facial soft tissue. Finally, a non-linear finite mixed element model is developed to estimate the tissue deformation induced by the prescribed bone remodelling plan.
  
  
  RESULTS
  The performance of the proposed collision detection algorithm has been improved in memory requirements and computational efficiency compared with conventional methods. In addition, the methodology is evaluated over both synthetic and real data, with simulation performance averaging <0.5 mm pointwise error over the facial surface in six mid-face distraction osteotogenesis procedures.
  
  
  CONCLUSIONS
  The experimental results support the novel methodological advancements in collision detection and biomechanical modelling proposed in this work.
authors: Department of Automation, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China. szwang.smu@gmail.com
authors: Shengzheng
authors: S
authors: Wang
authors: Jie
authors: J
authors: Yang
authors: James C
authors: JC
authors: Gee
mesh_terms: D000465:Algorithms; D001696:Biomechanical Phenomena; D016723:Bone Remodeling / Q000502:physiology*; D003198:Computer Simulation; D003394:Craniofacial Dysostosis / Q000503:physiopathology / Q000601:surgery*; D062109:Dermatologic Surgical Procedures; D004548:Elasticity; D005152:Facial Muscles / Q000502:physiology / Q000601:surgery; D020342:Finite Element Analysis; D006801:Humans; D008437:Maxilla / Q000502:physiology / Q000601:surgery; D008954:Models, Biological; D017711:Nonlinear Dynamics; D019647:Oral Surgical Procedures / Q000379:methods*; D011300:Preoperative Care / Q000379:methods*; D013314:Stress, Mechanical