title: Assessments of nasal bone fracture effects on nasal airflow: A computational fluid dynamics study.
abstract: BACKGROUND
  The aim of this study was to evaluate effects of nasal bone fractures on nasal aerodynamic flow patterns using computational fluid dynamics (CFD) simulations.
  
  
  METHODS
  A three-dimensional model of nasal cavity with a nasal bone fracture was constructed from computerized tomography (CT) scans of a patient with use of software Mimics 13.0 (The Materilize Group, Leuven, Belgium). CFD simulations were performed using Fluent 6.3 (ANSYS, Inc., Canonsburg, PA) with a turbulent flow model. Numerical results were presented with velocity, streamline, and pressure contour distributions in left and right nasal cavities and were compared with those of a healthy one. Possible outcomes on functional performances or patencies of the nose were also examined and discussed.
  
  
  RESULTS
  For the nose with a nasal bone fracture, distributions of velocity contours showed there was more airflow in the right nasal cavity than in the left one, especially for inspiration status. In the left cavity, the airflow was redirected irregularly and there were also more circulations with larger sizes, higher pressure jumps, and greater wall shear stresses. Flow partitioning in the right and left cavities was noticeable with a larger nasal resistance compared with the healthy one. When the inspirational flow rate was increased, pressure jump from the nostril to the nasopharynx increased faster.
  
  
  CONCLUSIONS
  The aerodynamic flow was redistributed greatly for the nose with a nasal bone fracture compared with the healthy one, which might affect local normal nasal functions. Such physical assessments of nasal airflow based on a model from the patients' CT scans may help clinicians determine the best treatment in advance.
authors.affiliation: Department of Mechanical Engineering, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Xiao Bing
authors.initials: XB
authors.lastname: Chen
authors.forename: Heow Pueh
authors.initials: HP
authors.lastname: Lee
authors.forename: Vincent Fook Hin
authors.initials: VF
authors.lastname: Chong
authors.forename: De Yun
authors.initials: de Y
authors.lastname: Wang
mesh_terms: D000328:Adult; D003198:Computer Simulation; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D057446:Hydrodynamics; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D009295:Nasal Bone / Q000000981:diagnostic imaging / Q000473:pathology*; D009296:Nasal Cavity / Q000000981:diagnostic imaging* / Q000473:pathology; D012123:Pulmonary Ventilation; D012984:Software; D014057:Tomography, X-Ray Computed