title: Computer-aided design-based preoperative planning of screw osteosynthesis for type B condylar head fractures: A preliminary study.
abstract: OBJECTIVE
  To investigate the clinical application of a new computer-aided design - (CAD) based planning method for the treatment of type B condylar head fractures without fragmentation.
  
  
  METHODS
  A total of 13 adult patients (19 sides) with type B condylar head fractures were included in the study. In all cases, imaging was performed using cone bean computed tomography (CBCT) preoperative, and Digital Imaging and Communications in Medicine (DICOM) files were imported into Simplant 11.04 software. The fracture of the mandibular condyle was reconstructed by a three-dimensional reconstruction module, and the simulation of reduction was achieved according to the morphological characteristics. Preoperative design was performed based on the CAD technology, and the three-dimensional interface was used to determine the length, location, and orientation of the positional screw. Osteosynthesis was performed with a single positional screw according to the optimum direction assessed in the preoperative planning CBCT, and the result was confirmed with postoperative CBCT scans and clinical follow-up.
  
  
  RESULTS
  Preoperative computer-aided design was able to predict the length, location, and direction of the positional screw. Postoperative CBCT results demonstrated that 12 cases (18 sides) were consistent with preoperative design with exception of one case (one side) due to unexpected rupture of the fragment. Six-month follow-up showed the condylar fractures were anatomically repositioned and that healing was excellent in 12 cases (18 sides) with minor displacement and resorption in one case (one side). Postoperative occlusion in all cases was excellent, and the maximum mouth opening improved from mean 1.2 cm preoperatively to a of mean 4.3 cm at 6 months postoperatively. The data for mandibular movements at 6 months postoperatively demonstrated the recovery of protrusion, without higher grade limitations for laterotrusion. In one case, there appeared to be mandibular deviation (<0.5 cm) with mouth opening.
  
  
  CONCLUSIONS
  The new preoperative design provides relevant data for screw osteosynthesis to enhance the precision and effectiveness of open reduction and internal fixation type B condylar head fractures.
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, People's Republic of China.
authors.forename: Song-song
authors.initials: SS
authors.lastname: Guo
authors.affiliation: Department of Polyclinic Dentistry, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, People's Republic of China.
authors.forename: Wei-na
authors.initials: WN
authors.lastname: Zhou
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, People's Republic of China.
authors.forename: Lin-zhong
authors.initials: LZ
authors.lastname: Wan
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yuan
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, People's Republic of China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, People's Republic of China. Electronic address: danxiangren2006@163.com.
authors.forename: Yi-fei
authors.initials: YF
authors.lastname: Du
authors.affiliation: Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing 210029, People's Republic of China. Electronic address: jhbcd@sina.com.
authors.forename: Hong-bing
authors.initials: HB
authors.lastname: Jiang
mesh_terms: D001863:Bone Screws; D017076:Computer-Aided Design; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008335:Mandibular Condyle / Q000293:injuries* / Q000601:surgery; D008337:Mandibular Fractures / Q000601:surgery*; D010347:Patient Care Planning; D016896:Treatment Outcome
keywords: Computer-aided design; Condylar head fractures; Positional screw; Preoperative design; Screw osteosynthesis