title: Combined soft and skeletal tissue modelling of normal and dysmorphic midface postnatal development.
abstract: BACKGROUND
  Midface hypoplasia as exemplified by Treacher Collins Syndrome (TCS) can impair appearance and function. Reconstruction involves multiple invasive surgeries with variable long-term outcomes. This study aims to describe normal and dysmorphic midface postnatal development through combined modelling of skeletal and soft tissues and to develop a surgical evaluation tool.
  
  
  METHODS
  Midface skeletal and soft tissue surfaces were extracted from computed tomography scans of 52 control and 14 TCS children, then analysed using dense surface modelling. The model was used to describe midface growth, morphology, and asymmetry, then evaluate postoperative outcomes.
  
  
  RESULTS
  Parameters responsible for the greatest variation in midface size and shape showed differences between TCS and controls with close alignment between skeletal and soft tissue models. TCS children exhibited midface dysmorphology and hypoplasia when compared with controls. Asymmetry was also significantly higher in TCS midfaces. Combined modelling was used to evaluate the impact of surgery in one TCS individual who showed normalisation immediately after surgery but reversion towards TCS dysmorphology after 1 year.
  
  
  CONCLUSIONS
  This is the first quantitative analysis of postnatal midface development using combined modelling of skeletal and soft tissues. We also provide an approach for evaluation of surgical outcomes, laying the foundations for future development of a preoperative planning tool.
authors.affiliation: UCL Great Ormond Street Institute of Child Health (Head: Prof. R. Smyth), University College London, London WC1N 1EH, United Kingdom; Department of Plastic Surgery, Great Ormond Street Hospital NHS Trust, London WC1N 3JH, United Kingdom.
authors.forename: Amel
authors.initials: A
authors.lastname: Ibrahim
authors.affiliation: UCL Great Ormond Street Institute of Child Health (Head: Prof. R. Smyth), University College London, London WC1N 1EH, United Kingdom; Nuffield Department of Obstetrics & Gynaecology, University of Oxford, Oxford OX3 7DQ, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Suttie
authors.affiliation: UCL Great Ormond Street Institute of Child Health (Head: Prof. R. Smyth), University College London, London WC1N 1EH, United Kingdom; Department of Plastic Surgery, Great Ormond Street Hospital NHS Trust, London WC1N 3JH, United Kingdom.
authors.forename: Neil W
authors.initials: NW
authors.lastname: Bulstrode
authors.affiliation: Department of Plastic Surgery, Great Ormond Street Hospital NHS Trust, London WC1N 3JH, United Kingdom.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Britto
authors.affiliation: UCL Great Ormond Street Institute of Child Health (Head: Prof. R. Smyth), University College London, London WC1N 1EH, United Kingdom; Department of Plastic Surgery, Great Ormond Street Hospital NHS Trust, London WC1N 3JH, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Dunaway
authors.affiliation: UCL Great Ormond Street Institute of Child Health (Head: Prof. R. Smyth), University College London, London WC1N 1EH, United Kingdom; Nuffield Department of Obstetrics & Gynaecology, University of Oxford, Oxford OX3 7DQ, United Kingdom. Electronic address: peter.hammond@obs-gyn.ox.ac.uk.
authors.forename: Peter
authors.initials: P
authors.lastname: Hammond
authors.affiliation: UCL Great Ormond Street Institute of Child Health (Head: Prof. R. Smyth), University College London, London WC1N 1EH, United Kingdom. Electronic address: p.ferretti@ucl.ac.uk.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Ferretti
mesh_terms: D016022:Case-Control Studies; D002508:Cephalometry; D002648:Child; D002675:Child, Preschool; D005145:Face / Q000000981:diagnostic imaging / Q000601:surgery*; D005147:Facial Bones / Q000000981:diagnostic imaging / Q000254:growth & development / Q000601:surgery; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007223:Infant; D008297:Male; D008342:Mandibulofacial Dysostosis / Q000000981:diagnostic imaging / Q000601:surgery*; D008445:Maxillofacial Development; D019651:Plastic Surgery Procedures / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Dense surface modelling; Development; Dysmorphology; Midface; Principal component analysis; Treacher Collins syndrome