title: Comparison of Neck Screw and Conventional Fixation Techniques in Mandibular Condyle Fractures Using 3-Dimensional Finite Element Analysis.
abstract: OBJECTIVE
  To compare the mechanical stress on the mandibular condyle after the reduction and fixation of mandibular condylar fractures using the neck screw and 2 other conventional techniques according to 3-dimensional finite element analysis.
  
  
  METHODS
  A 3-dimensional finite element model of a mandible was created and graphically simulated on a computer screen. The model was fixed with 3 different techniques: a 2.0-mm plate with 4 screws, 2 plates (1 1.5-mm plate and 1 2.0-mm plate) with 4 screws, and a neck screw. Loads were applied that simulated muscular action, with restrictions of the upper movements of the mandible, differentiation of the cortical and medullary bone, and the virtual "folds" of the plates and screws so that they could adjust to the condylar surface. Afterward, the data were exported for graphic visualization of the results and quantitative analysis was performed.
  
  
  RESULTS
  The 2-plate technique exhibited better stability in regard to displacement of fractures, deformity of the synthesis materials, and minimum and maximum tension values. The results with the neck screw were satisfactory and were similar to those found when a miniplate was used.
  
  
  CONCLUSIONS
  Although the study shows that 2 isolated plates yielded better results compared with the other groups using other fixation systems and methods, the neck screw could be an option for condylar fracture reduction.
authors: Specialist and Master of Oral and Maxillofacial Surgery, PhD Candidate in Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: ricardo_conci@hotmail.com.
authors: Ricardo Augusto
authors: RA
authors: Conci
authors: Specialist and Master Candidate in Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors: Flavio Henrique Silveira
authors: FH
authors: Tomazi
authors: Mechanical Engineer, Three-Dimensional Technologies Division, Renato Archer Center for Information Technology, Brazilian Ministry of Science and Technology, Campinas, Brazil.
authors: Pedro Yoshito
authors: PY
authors: Noritomi
authors: Chemical Engineer, Three-Dimensional Technologies Division, Renato Archer Center for Information Technology, Brazilian Ministry of Science and Technology, Campinas, Brazil.
authors: Jorge Vicente Lopes
authors: JV
authors: da Silva
authors: Professor, Department of Oral and Maxillofacial Surgery, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors: Guilherme Genehr
authors: GG
authors: Fritscher
authors: Professor, Department of Oral and Maxillofacial Surgery, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors: Claiton
authors: C
authors: Heitz
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001696:Biomechanical Phenomena; D001860:Bone Plates; D001863:Bone Screws; D003198:Computer Simulation; D055119:Elastic Modulus; D020342:Finite Element Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods*; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008335:Mandibular Condyle / Q000293:injuries* / Q000601:surgery; D008337:Mandibular Fractures / Q000601:surgery*; D008954:Models, Biological; D009068:Movement; D011626:Pterygoid Muscles / Q000502:physiology; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry; D014584:User-Computer Interface
chemical_list: D001672:Biocompatible Materials; D014025:Titanium