title: Virtual reconstruction of midface defects using statistical shape models.
abstract: OBJECTIVE
  This study evaluates the accuracy of a statistical shape model (SSM) for virtual fracture reconstruction of the lateral midface.
  
  
  METHODS
  A uniform bony defect of the right zygoma was created. A virtual reconstruction was performed by using the standard procedure of mirroring the unaffected to the affected side (Group I) and by using the statistical model based on 178 pathologically unaffected CT scans (Group II). The accuracy of the statistical shape model was evaluated in comparison to the present mirroring protocol. The reconstructed region was compared with the original bone evaluating the mean deviation of both surfaces.
  
  
  RESULTS
  All zygomas could be reconstructed with all methods. On the affected side the mean deviation was 1.10 mm ± 0.23 mm in group I and 0.85 mm ± 0.26 mm in group II. The differences between the groups were significant.
  
  
  CONCLUSIONS
  SSM offers a more precise reconstruction of midface defects than mirroring procedures. As an additional element SSM could automatize the CAS workflow in many respects.
authors.affiliation: Department of Oral and Maxillofacial Surgery (Chairman: Prof. Dr. Dr. Rainer Schmelzeisen), Albert-Ludwigs University Freiburg, Hugstetterstr. 55, 79106 Freiburg, Germany. Electronic address: wiebke.semper.hogg@uniklinik-freiburg.de.
authors.forename: Wiebke
authors.initials: W
authors.lastname: Semper-Hogg
authors.affiliation: Department of Oral and Maxillofacial Surgery (Chairman: Prof. Dr. Dr. Rainer Schmelzeisen), Albert-Ludwigs University Freiburg, Hugstetterstr. 55, 79106 Freiburg, Germany. Electronic address: marc.anton.fuessinger@uniklinik-freiburg.de.
authors.forename: Marc Anton
authors.initials: MA
authors.lastname: Fuessinger
authors.affiliation: Department of Oral and Maxillofacial Surgery (Chairman: Prof. Dr. Dr. Rainer Schmelzeisen), Albert-Ludwigs University Freiburg, Hugstetterstr. 55, 79106 Freiburg, Germany. Electronic address: steffen.schwarz@uniklinik-freiburg.de.
authors.forename: Steffen
authors.initials: S
authors.lastname: Schwarz
authors.affiliation: Department of Oral and Maxillofacial Surgery (Chairmann: Edward Ellis III, D.D.S., M.S., PhD), University of Texas Health Science Center at San Antonio, 8210 Floyd Curl Drive, MC8124, 78229-3923 San Antonio, USA. Electronic address: EllisE3@uthscsa.edu.
authors.forename: Edward
authors.initials: E
authors.lastname: Ellis
authors.affiliation: Department of Oral and Maxillofacial Surgery (Chairmann: Prof. Dr. Dr. Michael Ehrenfeld), Ludwig-Maximilians-University Munich, Lindwurmstr. 2a, 80137 Munich, Germany. Electronic address: peter.cornelius@med.lmu.de.
authors.forename: Carl-Peter
authors.initials: CP
authors.lastname: Cornelius
authors.affiliation: Department of Oral and Maxillofacial Surgery (Chairmann: Edward Ellis III, D.D.S., M.S., PhD), University of Texas Health Science Center at San Antonio, 8210 Floyd Curl Drive, MC8124, 78229-3923 San Antonio, USA. Electronic address: florian.probst@med.lmu.de.
authors.forename: Florian
authors.initials: F
authors.lastname: Probst
authors.affiliation: Department of Oral and Maxillofacial Surgery (Chairman: Prof. Dr. Dr. Rainer Schmelzeisen), Albert-Ludwigs University Freiburg, Hugstetterstr. 55, 79106 Freiburg, Germany. Electronic address: marc.metzger@uniklinik-freiburg.de.
authors.forename: Marc Christian
authors.initials: MC
authors.lastname: Metzger
authors.affiliation: Department of Physical Anthropology (Chairman: Prof. Dr. Ursula Wittwer-Backofen), Albert-Ludwigs University Freiburg, Hebelstr. 29, 79104 Freiburg, Germany. Electronic address: stefan.schlager@uniklinik-freiburg.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schlager
mesh_terms: D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D015233:Models, Statistical; D025321:Surgery, Computer-Assisted; D015050:Zygoma / Q000033:anatomy & histology*
keywords: Computer-assisted surgery (CAS); Fracture reconstruction; Midface defect; Statistical shape model (SSM)