title: Virtual skeletal complex model- and landmark-guided orthognathic surgery system.
abstract: In this study, correction of the maxillofacial deformities was performed by repositioning bone segments to an appropriate location according to the preoperative planning in orthognathic surgery. The surgery was planned using the patient's virtual skeletal models fused with optically scanned three-dimensional dentition. The virtual maxillomandibular complex (MMC) model of the patient's final occlusal relationship was generated by fusion of the maxillary and mandibular models with scanned occlusion. The final position of the MMC was simulated preoperatively by planning and was used as a goal model for guidance. During surgery, the intraoperative registration was finished immediately using only software processing. For accurate repositioning, the intraoperative MMC model was visualized on the monitor with respect to the simulated MMC model, and the intraoperative positions of multiple landmarks were also visualized on the MMC surface model. The deviation errors between the intraoperative and the final positions of each landmark were visualized quantitatively. As a result, the surgeon could easily recognize the three-dimensional deviation of the intraoperative MMC state from the final goal model without manually applying a pointing tool, and could also quickly determine the amount and direction of further MMC movements needed to reach the goal position. The surgeon could also perform various osteotomies and remove bone interference conveniently, as the maxillary tracking tool could be separated from the MMC. The root mean square (RMS) difference between the preoperative planning and the intraoperative guidance was 1.16 ± 0.34 mm immediately after repositioning. After surgery, the RMS differences between the planning and the postoperative computed tomographic model were 1.31 ± 0.28 mm and 1.74 ± 0.73 mm for the maxillary and mandibular landmarks, respectively. Our method provides accurate and flexible guidance for bimaxillary orthognathic surgery based on intraoperative visualization and quantification of deviations for simulated postoperative MMC and landmarks. The guidance using simulated skeletal models and landmarks can complement and improve conventional navigational surgery for bone repositioning in the craniomaxillofacial area.
authors.affiliation: Department of Biomedical Radiation Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea.
authors.forename: Sang-Jeong
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Biomedical Radiation Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, South Korea.
authors.forename: Sang-Yoon
authors.initials: SY
authors.lastname: Woo
authors.affiliation: Department of Oral and Maxillofacial Radiology, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Kyung-Hoe
authors.initials: KH
authors.lastname: Huh
authors.affiliation: Department of Oral and Maxillofacial Radiology, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Sam-Sun
authors.initials: SS
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Radiology, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Min-Suk
authors.initials: MS
authors.lastname: Heo
authors.affiliation: Department of Oral and Maxillofacial Radiology, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Soon-Chul
authors.initials: SC
authors.lastname: Choi
authors.affiliation: Department of Oral and Maxillofacial Surgery, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Jeong Joon
authors.initials: JJ
authors.lastname: Han
authors.affiliation: Department of Oral and Maxillofacial Surgery, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
authors.forename: Hoon Joo
authors.initials: HJ
authors.lastname: Yang
authors.affiliation: Department of Oral and Maxillofacial Surgery, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea. Electronic address: sjhwang@snu.ac.kr.
authors.forename: Soon Jung
authors.initials: SJ
authors.lastname: Hwang
authors.affiliation: Department of Oral and Maxillofacial Radiology, BK21, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea. Electronic address: wjyi@snu.ac.kr.
authors.forename: Won-Jin
authors.initials: WJ
authors.lastname: Yi
mesh_terms: D059925:Anatomic Landmarks; D003198:Computer Simulation; D003817:Dentition; D006801:Humans; D021621:Imaging, Three-Dimensional; D008334:Mandible / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D056948:Orthognathic Surgical Procedures; D025321:Surgery, Computer-Assisted; D014584:User-Computer Interface
keywords: 3D registration; Orthognathic surgery; Virtual model- and landmark-guided transfer; Virtual skeletal complex model; Virtual surgery planning