title: Development of customized positioning guides using computer-aided design and manufacturing technology for orthognathic surgery.
abstract: OBJECTIVE
  The purpose of this study was to devise a method for producing customized positioning guides for translating virtual plans to actual orthognathic surgery, and evaluation of the feasibility and validity of the devised method.
  
  
  METHODS
  Patients requiring two-jaw orthognathic surgery were enrolled and consented before operation. Two types of positioning guides were designed and fabricated using computer-aided design and manufacturing technology: One of the guides was used for the LeFort I osteotomy, and the other guide was used for positioning the maxillomandibular complex. The guides were fixed to the medial side of maxilla. For validation, the simulation images and postoperative cone beam computed tomography images were superimposed using surface registration to quantify the difference between the images. The data were presented in root-mean-square difference (RMSD) values.
  
  
  RESULTS
  Both sets of guides were experienced to provide ideal fit and maximal contact to the maxillary surface to facilitate their accurate management in clinical applications. The validation results indicated that RMSD values between the images ranged from 0.18 to 0.33 mm in the maxilla and from 0.99 to 1.56 mm in the mandible. The patients were followed up for 6 months or more, and all of them were satisfied with the results.
  
  
  CONCLUSIONS
  The proposed customized positioning guides are practical and reliable for translation of virtual plans to actual surgery. Furthermore, these guides improved the efficiency and outcome of surgery. This approach is uncomplicated in design, cost-effective in fabrication, and particularly convenient to use.
authors.affiliation: Craniofacial Research Center, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan. sharley@hust.edu.tw.
authors.forename: Hsiu-Hsia
authors.initials: HH
authors.lastname: Lin
authors.affiliation: Craniofacial Research Center, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Hsin-Wen
authors.initials: HW
authors.lastname: Chang
authors.affiliation: Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Chang Gung University, 5, Fu-Shin Street, Kwei Shan, Taoyuan, 333, Taiwan. lunjoulo@cgmh.org.tw.
authors.forename: Lun-Jou
authors.initials: LJ
authors.lastname: Lo
mesh_terms: D000293:Adolescent; D000328:Adult; D017076:Computer-Aided Design; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D056948:Orthognathic Surgical Procedures / Q000379:methods*; D010347:Patient Care Planning; D056888:Patient Positioning; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014584:User-Computer Interface; D055815:Young Adult
keywords: Computer-aided design and manufacturing; Maxillomandibular complex; Orthognathic surgery; Positioning guides; Superimposition