title: Navigation in Orthognathic Surgery: 3D Accuracy.
abstract: This article aims to determine the absolute accuracy of maxillary repositioning during orthognathic surgery according to simulation-guided navigation, that is, the combination of navigation and three-dimensional (3D) virtual surgery. We retrospectively studied 15 patients treated for asymmetric dentofacial deformities at the Oral and Maxillofacial Surgery Unit of the S.Orsola-Malpighi University Hospital in Bologna, Italy, from January 2010 to January 2012. Patients were scanned with a cone-beam computed tomography before and after surgery. The virtual surgical simulation was realized with a dedicated software and loaded on a navigation system to improve intraoperative reproducibility of the preoperative planning. We analyzed the outcome following two protocols: (1) planning versus postoperative 3D surface analysis; (2) planning versus postoperative point-based analysis. For 3D surface comparison, the mean Hausdorff distance was measured, and median among cases was 0.99 mm. Median reproducibility < 1 mm was 61.88% and median reproducibility < 2 mm was 85.46%. For the point-based analysis, with sign, the median distance was 0.75 mm in the frontal axis, -0.05 mm in the caudal-cranial axis, -0.35 mm in the lateral axis. In absolute value, the median distance was 1.19 mm in the frontal axis, 0.59 mm in the caudal-cranial axis, and 1.02 mm in the lateral axis. We suggest that simulation-guided navigation makes accurate postoperative outcomes possible for maxillary repositioning in orthognathic surgery, if compared with the surgical computer-designed project realized with a dedicated software, particularly for the vertical dimension, which is the most challenging to manage.
authors.affiliation: Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Badiali
authors.affiliation: Computational Bio-Engineering Laboratory, Rizzoli Orthopedic Institute, Bologna, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Roncari
authors.affiliation: Oral and Maxillofacial Surgery Unit, S.Orsola-Malpighi University Hospital, Bologna, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Bianchi
authors.affiliation: Medical Technology Laboratory, Rizzoli Orthopedic Institute, Bologna, Italy.
authors.forename: Fulvia
authors.initials: F
authors.lastname: Taddei
authors.affiliation: Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Marchetti
authors.affiliation: Computational Bio-Engineering Laboratory, Rizzoli Orthopedic Institute, Bologna, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Schileo
mesh_terms: D000293:Adolescent; D000328:Adult; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D057909:Orthognathic Surgery / Q000379:methods*; D012189:Retrospective Studies; D055815:Young Adult