title: [Analysis of the influence of lower premolar rotation on TMJ stress distribution by finite element method].
abstract: OBJECTIVE
  To evaluate the resultant differences of stress distribution in bilateral condyle when occlusal loads were changed with teeth rotation.
  
  
  METHODS
  A three-dimensional FEA model containing human TMJ and left lower second premolar was developed using commercial FEA software ANSYS. Lower second premolar was applied with ICO occlusal loading in the load case 1. According to the same upper dentition in the load case 2, lower premolar was applied with occlusal loading when it was rotated 30 degree counter-clockwise in Frankfort horizontal plane level. In this two load cases,the different stress distributions of the condyle was investigated.
  
  
  RESULTS
  The stress distribution of loading side condyle had changed abnormally when premolar rotation was performed. It had showed more disorderly than ICO loading in load case 1. In load case 1 the maximum main stress and Von Mises stress values increased from medial pole to lateral pole. In load case 2,the stress values mainly decreased from medial pole to lateral pole, but along the path there were some parts with values-increasing. The stress values of bilateral condyle in load case 2 were lower than that in load case 1, especially for the stress values of the opposite condyle.
  
  
  CONCLUSIONS
  The stress distribution of loading side condyle got in disorder resulting from rotation of unilateral lower premolar.
authors.affiliation: Department of Anatomy and Physiology, Stomatological College, Fourth Military Medical University, Xi'an 710032, Shanxi Province, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Mei-qing
authors.initials: MQ
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Ling
mesh_terms: D001641:Bicuspid; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D008310:Malocclusion; D012399:Rotation; D013314:Stress, Mechanical; D013704:Temporomandibular Joint