title: Quantitative analysis of dual-purpose, patient-specific craniofacial implants for correction of temporal deformity.
abstract: BACKGROUND
  The development of computer-assisted design, virtual modeling, and computed tomography has allowed precise customization of implants for patients who undergo neurosurgical or craniofacial surgery procedures. However, such techniques and implant designs have not adequately addressed temporal asymmetry due to postoperative bone resorption, temporalis muscle malposition/foreshortening, and/or temporal fat pad atrophy.
  
  
  OBJECTIVE
  We hypothesized that an alteration in customized craniofacial implant (CCI) design with a strategic extension inferolaterally and excessive material bulking would provide simultaneous reconstruction of coexisting temporal skull defects and therefore reduce the effect of soft tissue deformities.
  
  
  METHODS
  A single-surgeon, single-institution retrospective cohort study was performed to include 10 consecutive subjects who underwent cranioplasty reconstruction with modified implants during a 3-year period. Implants were placed with the use of our previously described pericranial-onlay technique. With the use of a computed tomography-based, computer-assisted design/manufacturing methodology, novel dual-purpose implants were designed to prevent and/or correct persistent temporal hollowing. The efficacy of the new CCI shape and design for cranial restoration of temporal symmetry was analyzed in both 2 and 3 dimensions.
  
  
  RESULTS
  In 2-dimensional analyses, the modified implant provided enhanced lateral projection (21%; 1.06 cm(3)) in areas closest to the temporal arch. Three-dimensional volumetric analyses demonstrated that additional bulking totaled 24 ± 11 cm(3) (range, 9-43 cm), which essentially replaced 40 ± 13.7% (range, 26%-60%) of the absent temporal volume contributing to persistent temporal hollowing.
  
  
  CONCLUSIONS
  Computer-designed, dual-purpose CCIs can be safely created with unprecedented shape to prevent and/or eradicate postoperative temporal deformity.
authors.affiliation: *The University of Illinois College of Medicine, Rockford, Illinois; ‡Department of Plastic and Reconstructive Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland; §Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Shuting
authors.initials: S
authors.lastname: Zhong
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Huang
authors.forename: Srinivas M
authors.initials: SM
authors.lastname: Susarla
authors.forename: Edward W
authors.initials: EW
authors.lastname: Swanson
authors.forename: Judy
authors.initials: J
authors.lastname: Huang
authors.forename: Chad R
authors.initials: CR
authors.lastname: Gordon
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D017076:Computer-Aided Design; D005147:Facial Bones / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D012886:Skull / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D055815:Young Adult