title: Registration strategy using occlusal splint based on augmented reality for mandibular angle oblique split osteotomy.
abstract: BACKGROUND
  An augmented reality tool allows for visual tracking of real anatomic structures in superposition with volume-rendered computed tomographic or magnetic resonance imaging scans and thus can be used for navigated translocation of important structures during operation. In this feasibility study, ARToolKit was used in mandibular angle oblique split osteotomy to define the cutting planes according to an operative plan.
  
  
  METHODS
  We overlay the operative plan on the model of a mandible made by rapid prototyping technology, and the technology was successfully used in 15 patients. Before the operation, all patients underwent computed tomographic scan, and dental casts were prepared by surgeons. Then, surgeons make the occlusal splint according to a dental cast to fix the marker, which can be recognized by the ARToolKit. The occlusal splint and marker were transformed to three-dimensional data using a laser scanner, and a programmer that runs on a personal computer named Rapidform matches the marker and the mandible image to generate the virtual image. By this step, the virtual image describing the marker, occlusal splint, and the mandible image of the patient are integrated. During the operation, the operative plan was overlaid on the rapid prototyping model of the mandible as soon as the ARToolKit recognized the marker.
  
  
  RESULTS
  The technology was successfully used in 15 patients; the virtual image of the mandible and the cutting-plane both overlaid the real model of the mandible.
  
  
  CONCLUSIONS
  This study has reported a new and effective way for mandibular angle oblique split osteotomy, and using occlusal splint might be a powerful option for the registration of augmented reality. Augmented reality tools like ARToolKit may be helpful for control of maxillary translocation in orthognathic surgery.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhu
authors.forename: Gang
authors.initials: G
authors.lastname: Chai
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Ma
authors.forename: Jiliang
authors.initials: J
authors.lastname: Gan
mesh_terms: D006801:Humans; D021621:Imaging, Three-Dimensional; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D003765:Models, Dental; D017090:Occlusal Splints; D056948:Orthognathic Surgical Procedures / Q000379:methods*; D012984:Software; D014057:Tomography, X-Ray Computed