title: Three-dimensional head shape quantification for infants with and without deformational plagiocephaly.
abstract: OBJECTIVE
  The authors developed and tested three-dimensional (3D) indices for quantifying the severity of deformational plagiocephaly (DP).
  
  
  METHODS
  The authors evaluated the extent to which infants with and without DP (as determined by clinic referral and two experts' ratings) could be correctly classified.
  
  
  METHODS
  Infants aged 4 to 11 months, including 154 with diagnosed DP and 100 infants without a history of DP or other craniofacial condition. After excluding participants with discrepant expert ratings, data from 90 infants with DP and 50 infants without DP were retained.
  
  
  METHODS
  Two-dimensional (2D) histograms of surface normal vector angles were extracted from 3D mesh data and used to compute the severity scores.
  
  
  METHODS
  Left posterior flattening score (LPFS), right posterior flattening score (RPFS), asymmetry score (AS), absolute asymmetry score (AAS), and an approximation of a previously described 2D measure, the oblique cranial length ratio (aOCLR). Two-dimensional histograms localized the posterior flatness for each participant.
  
  
  METHODS
  The authors fit receiver operating characteristic curves and calculated the area under the curves (AUC) to evaluate the relative accuracy of DP classification using the above measures.
  
  
  RESULTS
  The AUC statistics were AAS = 91%, LPFS = 97%, RPFS = 91%, AS = 99%, and aOCLR = 79%.
  
  
  CONCLUSIONS
  Novel 3D-based plagiocephaly posterior severity scores provided better sensitivity and specificity in the discrimination of plagiocephalic and typical head shapes than the 2D measurements provided by a close approximation of OCLR. These indices will allow for more precise quantification of the DP phenotype in future studies on the prevalence of this condition, which may lead to improved clinical care.
authors.affiliation: Department of Computer Science and Engineering, University of Washington, Seattle, USA.
authors.forename: I
authors.initials: I
authors.lastname: Atmosukarto
authors.forename: L G
authors.initials: LG
authors.lastname: Shapiro
authors.forename: J R
authors.initials: JR
authors.lastname: Starr
authors.forename: C L
authors.initials: CL
authors.lastname: Heike
authors.forename: B
authors.initials: B
authors.lastname: Collett
authors.forename: M L
authors.initials: ML
authors.lastname: Cunningham
authors.forename: M L
authors.initials: ML
authors.lastname: Speltz
mesh_terms: D019540:Area Under Curve; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008953:Models, Anatomic; D049068:Plagiocephaly, Nonsynostotic / Q000145:classification*; D012720:Severity of Illness Index