title: Direct and continuous localization of anatomical landmarks for image-guided orthognathic surgery.
abstract: OBJECTIVE
  The accuracy and consistency of a new image-guided method for orthognathic surgery using direct and continuous landmark localization was compared with that of a conventional method.
  
  
  METHODS
  Maxillary and mandibular dental casts mounted on an articulator were used as a surgery phantom. We planned six types of surgeries including translations and rotations. The sequential positions of the landmarks determined before surgery could be traced and the difference between planned and actual positions of the landmarks could be visualized during surgery. The final deviation errors were determined with and without applying the pointing instrument to the landmarks.
  
  
  RESULTS
  The mean RMS accuracy of 0.47 ± 0.22 mm by direct localization was significantly higher than that of 1.06 ± 0.49 mm by the manual localization. There were no significant differences in accuracies for surgeries using the direct localization method.
  
  
  CONCLUSIONS
  The direct and continuous localization method showed higher accuracy and consistency than conventional manual localization in all phantom surgeries.
authors.affiliation: Department of Oral and Maxillofacial Radiology, BK21, and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea.
authors.forename: Seong-Ha
authors.initials: SH
authors.lastname: Kim
authors.forename: Dae-Seung
authors.initials: DS
authors.lastname: Kim
authors.forename: Kyung-Hoe
authors.initials: KH
authors.lastname: Huh
authors.forename: Sam-Sun
authors.initials: SS
authors.lastname: Lee
authors.forename: Min-Suk
authors.initials: MS
authors.lastname: Heo
authors.forename: Soon-Chul
authors.initials: SC
authors.lastname: Choi
authors.forename: Soon-Jung
authors.initials: SJ
authors.lastname: Hwang
authors.forename: Won-Jin
authors.initials: WJ
authors.lastname: Yi
mesh_terms: D000704:Analysis of Variance; D059925:Anatomic Landmarks / Q000502:physiology*; D002508:Cephalometry / Q000379:methods; D006801:Humans; D021621:Imaging, Three-Dimensional; D008334:Mandible / Q000601:surgery*; D008437:Maxilla / Q000601:surgery*; D008953:Models, Anatomic; D003765:Models, Dental; D056948:Orthognathic Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D010347:Patient Care Planning; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed