title: Measuring zygomaticomaxillary complex symmetry three-dimensionally with the use of mirroring and surface based matching techniques.
abstract: OBJECTIVE
  The study aim was to validate a new method for measuring zygomaticomaxillary complex (ZMC) symmetry, which can be helpful in analyzing ZMC fractures.
  
  
  METHODS
  Three-dimensional virtual hard-tissue models were reconstructed from computed tomography (CT) datasets of 26 healthy individuals. Models were mirrored and superimposed. Absolute average distance (AD) and 90th percentile distance (NPD) were used to measure overall and maximal symmetry. The Intraclass Correlation Coefficient (ICC) was calculated to measure interobserver consistency. In order to determine whether this technique is applicable in ZMC fracture cases, 10 CT datasets of individuals with a unilateral ZMC fracture were analyzed.
  
  
  RESULTS
  For the unaffected group the mean AD was 0.84 ± 0.29 mm (95% CI 0.72-0.96) and the mean NPD was 1.58 ± 0.43 mm (95% CI 1.41-1.76). The ICC was 0.97 (0.94-0.98 as 95% CI), indicating almost perfect interobserver agreement. In the affected group the mean AD was 2.97 ± 1.76 mm (95% CI 1.71-4.23) and the mean NPD was 6.12 ± 3.42 mm (95% CI 3.67-8.57). The affected group showed near-perfect interobserver agreement with an ICC of 0.996 (0.983-0.999 as 95% CI).
  
  
  CONCLUSIONS
  The method presented is an accurate instrument for evaluation of ZMC symmetry, which can be helpful for advanced diagnostics and treatment evaluation.
authors: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. J. de Lange), Orbital Unit, Academic Medical Centre of Amsterdam, University of Amsterdam, Academic Centre for Dentistry (ACTA), Meibergdreef 9, 1105 AZ Amsterdam ZO, The Netherlands. Electronic address: j.p.ho@amc.uva.nl.
authors: Jean Pierre T F
authors: JPTF
authors: Ho
authors: 3D Laboratory Oral and Maxillofacial Surgery (Head: Prof. Dr. J. de Lange), Academic Medical Centre of Amsterdam, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam ZO, The Netherlands. Electronic address: r.schreurs@amc.uva.nl.
authors: Ruud
authors: R
authors: Schreurs
authors: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. J. de Lange), Orbital Unit, Academic Medical Centre of Amsterdam, University of Amsterdam, Academic Centre for Dentistry (ACTA), Meibergdreef 9, 1105 AZ Amsterdam ZO, The Netherlands. Electronic address: d.m.milstein@amc.uva.nl.
authors: Dan M J
authors: DMJ
authors: Milstein
authors: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. J. de Lange), Orbital Unit, Academic Medical Centre of Amsterdam, University of Amsterdam, Academic Centre for Dentistry (ACTA), Meibergdreef 9, 1105 AZ Amsterdam ZO, The Netherlands. Electronic address: l.dubois@amc.uva.nl.
authors: Leander
authors: L
authors: Dubois
authors: 3D Laboratory Oral and Maxillofacial Surgery (Head: Prof. Dr. J. de Lange), Academic Medical Centre of Amsterdam, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam ZO, The Netherlands. Electronic address: Thomas.Maal@radboudumc.nl.
authors: Thomas J J
authors: TJJ
authors: Maal
authors: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. J. de Lange), Orbital Unit, Academic Medical Centre of Amsterdam, University of Amsterdam, Academic Centre for Dentistry (ACTA), Meibergdreef 9, 1105 AZ Amsterdam ZO, The Netherlands. Electronic address: j.delange@amc.uva.nl.
authors: Jan
authors: J
authors: de Lange
authors: Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. J. de Lange), Orbital Unit, Academic Medical Centre of Amsterdam, University of Amsterdam, Academic Centre for Dentistry (ACTA), Meibergdreef 9, 1105 AZ Amsterdam ZO, The Netherlands. Electronic address: ag.becking@amc.uva.nl.
authors: Alfred G
authors: AG
authors: Becking
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging / Q000473:pathology; D008440:Maxillary Fractures / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D015588:Observer Variation; D014057:Tomography, X-Ray Computed; D055815:Young Adult; D015050:Zygoma / Q000000981:diagnostic imaging / Q000473:pathology; D015051:Zygomatic Fractures / Q000000981:diagnostic imaging* / Q000473:pathology
keywords: Computer-assisted surgery; Iterative closest point; Surface-based matching; Symmetry; Zygomaticomaxillary complex