title: Describing Crouzon and Pfeiffer syndrome based on principal component analysis.
abstract: Crouzon and Pfeiffer syndrome are syndromic craniosynostosis caused by specific mutations in the FGFR genes. Patients share the characteristics of a tall, flattened forehead, exorbitism, hypertelorism, maxillary hypoplasia and mandibular prognathism. Geometric morphometrics allows the identification of the global shape changes within and between the normal and syndromic population.
  
  
  METHODS
  Data from 27 Crouzon-Pfeiffer and 33 normal subjects were landmarked in order to compare both populations. With principal component analysis the variation within both groups was visualized and the vector of change was calculated. This model normalized a Crouzon-Pfeiffer skull and was compared to age-matched normative control data.
  
  
  RESULTS
  PCA defined a vector that described the shape changes between both populations. Movies showed how the normal skull transformed into a Crouzon-Pfeiffer phenotype and vice versa. Comparing these results to established age-matched normal control data confirmed that our model could normalize a Crouzon-Pfeiffer skull.
  
  
  CONCLUSIONS
  PCA was able to describe deformities associated with Crouzon-Pfeiffer syndrome and is a promising method to analyse variability in syndromic craniosynostosis. The virtual normalization of a Crouzon-Pfeiffer skull is useful to delineate the phenotypic changes required for correction, can help surgeons plan reconstructive surgery and is a potentially promising surgical outcome measure.
authors: Great Ormond Street Hospital, London, United Kingdom. Electronic address: fcrstaal@gmail.com.
authors: Femke C R
authors: FC
authors: Staal
authors: Great Ormond Street Hospital, London, United Kingdom.
authors: Allan J T
authors: AJ
authors: Ponniah
authors: Great Ormond Street Hospital, London, United Kingdom.
authors: Freida
authors: F
authors: Angullia
authors: Medical Physics Department, University College London, London, United Kingdom.
authors: Clifford
authors: C
authors: Ruff
authors: Great Ormond Street Hospital, London, United Kingdom; Erasmus Medical Center, Maxillofacial Surgery, Rotterdam, The Netherlands.
authors: Maarten J
authors: MJ
authors: Koudstaal
authors: Great Ormond Street Hospital, London, United Kingdom.
authors: David
authors: D
authors: Dunaway
mesh_terms: D000168:Acrocephalosyndactylia / Q000145:classification* / Q000000981:diagnostic imaging; D000293:Adolescent; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D002648:Child; D003394:Craniofacial Dysostosis / Q000145:classification* / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D009040:Motion Pictures; D010347:Patient Care Planning; D010641:Phenotype; D025341:Principal Component Analysis; D019651:Plastic Surgery Procedures / Q000379:methods; D012886:Skull / Q000473:pathology; D036542:Tomography, Spiral Computed / Q000379:methods; D014584:User-Computer Interface
keywords: Craniosynostosis; Crouzon syndrome; FGFR2; Pfeiffer syndrome; Principal component analysis; Three-dimensional imaging