title: Planning surgical reconstruction in Treacher-Collins syndrome using virtual simulation.
abstract: BACKGROUND
  Treacher-Collins syndrome is a rare autosomal dominant condition of varying phenotypic expression. The surgical correction in this syndrome is difficult, and the approach varies between craniofacial departments worldwide. The authors aimed to design standardized tools for planning orbitozygomatic and mandibular reconstruction in Treacher-Collins syndrome using geometric morphometrics.
  
  
  METHODS
  The Great Ormond Street Hospital database was retrospectively identified for patients with Treacher-Collins syndrome. Thirteen children (aged 2 to 15 years) who had suitable preoperative three-dimensional computed tomographic head scans were included. Six Treacher-Collins syndrome three-dimensional computed tomographic head scans were quantitatively compared using a template of 96 anatomically defined landmarks to 26 age-matched normal dry skulls.
  
  
  RESULTS
  Thin-plate spline videos illustrated the characteristic deformities of retromicrognathia and maxillary and orbitozygomatic hypoplasia in the Treacher-Collins syndrome population. Geometric morphometrics was used in the virtual reconstruction of the orbitozygomatic and mandibular region in Treacher-Collins syndrome patients. Intrarater and interrater reliability of the landmarks was acceptable and within a standard deviation of less than 1 mm on 97 percent and 100 percent of 10 repeated scans, respectively.
  
  
  CONCLUSIONS
  Virtual normalization of the Treacher-Collins syndrome skull effectively describes characteristic skeletal deformities and provides a useful guide to surgical reconstruction. Size-matched stereolithographic templates derived from thin-plate spline warps can provide effective intraoperative templates for zygomatic and mandibular reconstruction in the Treacher-Collins syndrome patient.
  
  
  METHODS
  Diagnostic, V.
authors.affiliation: East Grinstead and London, United Kingdom From East Grinstead Hospital; Great Ormond Street Hospital; and University College London.
authors.forename: Dariush
authors.initials: D
authors.lastname: Nikkhah
authors.forename: Allan
authors.initials: A
authors.lastname: Ponniah
authors.forename: Cliff
authors.initials: C
authors.lastname: Ruff
authors.forename: David
authors.initials: D
authors.lastname: Dunaway
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005147:Facial Bones / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008342:Mandibulofacial Dysostosis / Q000000981:diagnostic imaging* / Q000601:surgery; D008954:Models, Biological; D011300:Preoperative Care; D019651:Plastic Surgery Procedures / Q000379:methods*; D014057:Tomography, X-Ray Computed