title: What happens between pure hydraulic and buckling mechanisms of blowout fractures?
abstract: OBJECTIVE
  The present study aims to evaluate how the ratio of the hydraulic and buckling mechanisms affects blowout fracture patterns, when these two mechanisms work simultaneously.
  
  
  METHODS
  Three-dimensional computer-aided-design (CAD)models were generated simulating ten skulls. To simulate impact, 1.2J was applied on the orbital region of these models in four patterns. Pattern 1: All the energy works to cause the hydraulic effect. Pattern 2: Two-thirds of the energy works to cause the hydraulic effect; one-third of the energy works to cause the buckling effect. Pattern 3: One-third of the energy works to cause the hydraulic effect; two-thirds of the energy works to cause the buckling effect. Pattern 4: The entire energy quantum works to cause the buckling effect. Using the finite element method, the regions where fractures were theoretically expected to occur were calculated and were compared between the four patterns.
  
  
  RESULTS
  More fracture damage occurred for Pattern 1 than Pattern 2, and for Pattern 3 than for Pattern 4.
  
  
  CONCLUSIONS
  The hydraulic and buckling mechanisms interact with one another. When these two mechanisms are combined, the orbital walls tend to develop serious fractures.
authors.affiliation: Department of Plastic and Reconstructive Surgery, School of Medicine, Keio University, Tokyo, Japan. nagasao@sc.itc.keio.ac.jp
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Nagasao
authors.forename: Junpei
authors.initials: J
authors.lastname: Miyamoto
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Hua
authors.initials: H
authors.lastname: Jiang
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D001696:Biomechanical Phenomena; D003198:Computer Simulation; D017076:Computer-Aided Design; D020342:Finite Element Analysis; D006801:Humans; D008422:Materials Testing; D008953:Models, Anatomic; D009917:Orbital Fractures / Q000209:etiology / Q000503:physiopathology; D013314:Stress, Mechanical