title: Biomechanical analysis of a curvilinear distractor device for correcting mandibular symphyseal defects.
abstract: OBJECTIVE
  The local mechanical environment is a determinant of successful transport disc distraction osteogenesis. This study assessed the biomechanics of a curvilinear distractor device for correcting mandibular symphyseal defects.
  
  
  METHODS
  The finite element method was used to analyze an intact mandible, mandibular distractor bodies with different rail thicknesses (4, 6, 8, and 10 mm), and mandibular distractor bodies with rails and auxiliary lingual brackets.
  
  
  RESULTS
  Rail thickness was positively correlated with maximum von Mises stress in the distractor and negatively correlated with maximum displacement of the mandibular distractor bodies. The maximum von Mises stress occurred at the junction of the rails and fixed arms. It also exceeded the yield strength of the titanium material. Compared with the maximum displacement of the intact mandible, that of the mandibular distractor bodies was visibly increased.
  
  
  CONCLUSIONS
  An auxiliary lingual bracket can effectively decrease stress in such devices and displacement of mandibular distractor bodies. Rail fixation alone cannot achieve stability for distraction osteogenesis. Using an auxiliary lingual bracket effectively prevents distractor breakage and exposure.
authors.affiliation: Doctor Degree Candidate, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University; Doctor in Charge, Department of Oral and Maxillofacial Surgery, First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Associate Professor, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Shang
authors.affiliation: Associate Professor, Department of Oral and Maxillofacial Surgery, First Affiliated Hospital, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China. Electronic address: lzdoccn@163.com.
authors.forename: Yanpu
authors.initials: Y
authors.lastname: Liu
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D055119:Elastic Modulus; D004867:Equipment Design; D004868:Equipment Failure; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008334:Mandible / Q000601:surgery*; D008336:Mandibular Diseases / Q000601:surgery*; D008406:Masseter Muscle / Q000502:physiology; D008954:Models, Biological; D016910:Orthodontic Brackets; D019857:Osteogenesis, Distraction / Q000295:instrumentation*; D011626:Pterygoid Muscles / Q000502:physiology; D013314:Stress, Mechanical; D013499:Surface Properties; D013703:Temporal Muscle / Q000502:physiology; D014025:Titanium / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D014025:Titanium