title: Modelling of orbital deformation using finite-element analysis.
abstract: The purpose of this study was to develop a three-dimensional finite-element model (FEM) of the human orbit, containing the globe, to predict orbital deformation in subjects following a blunt injury. This study investigated the hypothesis that such deformation could be modelled using finite-element techniques. One patient who had CT-scan examination to the maxillofacial skeleton including the orbits, as part of her treatment, was selected for this study. A FEM of one of the orbits containing the globe was constructed, based on CT-scan images. Simulations were performed with a computer using the finite-element software NISA (EMRC, Troy, USA). The orbit was subjected to a blunt injury of a 0.5 kg missile with 30 ms(-1) velocity. The FEM was then used to predict principal and shear stresses or strains at each node position. Two types of orbital deformation were predicted during different impact simulations: (i) horizontal distortion and (ii) rotational distortion. Stress values ranged from 213.4 to 363.3 MPa for the maximum principal stress, from -327.8 to -653.1 MPa for the minimum principal stress, and from 212.3 to 444.3 MPa for the maximum shear stress. This is the first finite-element study, which demonstrates different and concurrent patterns of orbital deformation in a subject following a blunt injury. Finite element modelling is a powerful and invaluable tool to study the multifaceted phenomenon of orbital deformation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Helsinki University Central Hospital, Kasarmikatu 11-13, PO Box 263, 00029 HUS, Helsinki, Finland. jehad.al-sukhun@hus.fi
authors.forename: Jehad
authors.initials: J
authors.lastname: Al-Sukhun
authors.forename: Christian
authors.initials: C
authors.lastname: Lindqvist
authors.forename: Risto
authors.initials: R
authors.lastname: Kontio
mesh_terms: D003198:Computer Simulation; D005131:Eye Injuries / Q000473:pathology; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D008953:Models, Anatomic; D008954:Models, Biological; D009915:Orbit / Q000293:injuries*; D012399:Rotation; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed; D014949:Wounds, Nonpenetrating / Q000473:pathology