title: Evaluation of stress changes in the mandible with a fixed functional appliance: a finite element study.
abstract: BACKGROUND
  The aim of this study was to evaluate the effects of a fixed functional appliance (Forsus Fatigue Resistant Device; 3M Unitek, Monrovia, Calif) on the mandible with 3-dimensional finite element stress analysis.
  
  
  METHODS
  A 3-dimensional finite element model of the mandible was constructed from the images generated by cone-beam computed tomography of a patient undergoing fixed orthodontic treatment. The changes were studied with the finite element method, in the form of highest von Mises stress and maximum principal stress regions.
  
  
  RESULTS
  More areas of stress were seen in the model of the mandible with the Forsus compared with the model of the mandible in the resting stage.
  
  
  CONCLUSIONS
  This fixed functional appliance studied by finite element model analysis caused increases in the maximum principal stress and the von Mises stress in both the cortical bone and the condylar region of the mandible by more than 2 times.
authors: Senior lecturer, Department of Orthodontics, Christian Dental College, Christian Medical College, Ludhiana, Punjab, India. Electronic address: dr.anshulchaudhry@gmail.com.
authors: Anshul
authors: A
authors: Chaudhry
authors: Director, postgraduate studies; professor and head, Department of Orthodontics, Shree Guru Gobind Singh Tricentenary Dental College, Hospital and Research Institute, Budhera, Gurgaon, Haryana, India.
authors: Maninder S
authors: MS
authors: Sidhu
authors: Senior lecturer, Department of Orthodontics, Baba Jaswant Singh Dental College, Hospital & Research Institute, Ludhiana, Punjab, India.
authors: Girish
authors: G
authors: Chaudhary
authors: Professor, Department of Orthodontics, Shree Guru Gobind Singh Tricentenary Dental College, Hospital and Research Institute, Budhera, Gurgaon, Haryana, India.
authors: Seema
authors: S
authors: Grover
authors: Formerly, postgraduate student, Department of Prosthodontics, Kothiwal Dental College, Moradabad, Uttar Pradesh, India.
authors: Nimisha
authors: N
authors: Chaudhry
authors: Private practice, Rohatak, Haryana, India.
authors: Ashutosh
authors: A
authors: Kaushik
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D001732:Bite Force; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008313:Malocclusion, Angle Class III / Q000628:therapy; D008334:Mandible / Q000503:physiopathology*; D008335:Mandibular Condyle / Q000503:physiopathology; D008406:Masseter Muscle / Q000503:physiopathology; D008954:Models, Biological; D009119:Muscle Contraction / Q000502:physiology; D016382:Orthodontic Appliance Design; D017289:Orthodontic Appliances, Functional; D011626:Pterygoid Muscles / Q000503:physiopathology; D063173:Retrognathia / Q000628:therapy; D013314:Stress, Mechanical; D013703:Temporal Muscle / Q000503:physiopathology; D014070:Tooth / Q000503:physiopathology