title: Increasing the accuracy of orbital reconstruction with selective laser-melted patient-specific implants combined with intraoperative navigation.
abstract: OBJECTIVE
  Advances in technology have allowed increasing degrees of accuracy in the treatment of orbital deformities. The purpose of this study was to compare the accuracy of pre-bent titanium mesh (PBTM) and selective laser-melted patient-specific implants (PSIs) in unilateral orbital reconstruction after traumatic injury. The authors hypothesized that selective laser-melted PSIs would more accurately reconstruct the orbit.
  
  
  METHODS
  A retrospective review of 34 cases of primary reconstruction of unilateral orbital fractures treated using selective laser-melted PSIs (group 1, n = 17) or PBTM (group 2, n = 17) was performed. The primary outcome measurements were orbital volume excess and the anterior, medial, and posterior intraorbital angles. The Mann-Whitney U test was used to assess the difference in orbital volume and angular deviation between the 2 groups. The level of statistical significance was set at .05. All P values were 2-sided.
  
  
  RESULTS
  The comparison of mean values for the 2 groups showed significant differences for the anterior angle (PBTM: mean, 11.3; standard deviation [SD], 1.8; PSI: mean, 4.1; SD, 0.7; P = .001), but not the medial (PBTM: mean, 11.6; SD, 2.0; PSI: mean, 8.2; SD, 1.9; P = .170) and posterior (PBTM: mean, 10.8, SD, 2.8; PSI: mean, 8.2, SD, 1.4; P = .760) angles between the unaffected and reconstructed orbits. The postoperative difference in volume between the unaffected and reconstructed orbits differed significantly between the 2 study groups (PBTM: mean, 0.6; SD, 0.1; PSI: mean, 0.4; SD, 0.1; P = .029).
  
  
  CONCLUSIONS
  The results of this study suggest that complex orbital fractures can be reconstructed with an even higher degree of accuracy with selective laser-melted PSIs than with PBTM.
authors.affiliation: Senior Consultant, Department of Craniomaxillofacial Surgery, Hannover Medical School, Hannover, Germany. Electronic address: rana.majeed@mh-hannover.de.
authors.forename: Majeed
authors.initials: M
authors.lastname: Rana
authors.affiliation: Clinical Fellow, Department of Craniomaxillofacial Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Christopher H K
authors.initials: CH
authors.lastname: Chui
authors.affiliation: Resident, Department of Craniomaxillofacial Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Maximillian
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Resident, Department of Craniomaxillofacial Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Ruediger
authors.initials: R
authors.lastname: Zimmerer
authors.affiliation: Associate Professor, Department of Craniomaxillofacial Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Madiha
authors.initials: M
authors.lastname: Rana
authors.affiliation: Professor and Department Head, Department of Craniomaxillofacial Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Nils-Claudius
authors.initials: NC
authors.lastname: Gellrich
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D017076:Computer-Aided Design; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005500:Follow-Up Studies; D018460:Fractures, Comminuted / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007834:Lasers; D008953:Models, Anatomic; D009915:Orbit / Q000473:pathology; D009917:Orbital Fractures / Q000601:surgery*; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019651:Plastic Surgery Procedures / Q000295:instrumentation / Q000379:methods*; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013526:Surgical Mesh; D014025:Titanium / Q000737:chemistry; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D014584:User-Computer Interface
chemical_list: D001672:Biocompatible Materials; D014025:Titanium