Mandibular angle fracture: evaluation of bone mechanical behavior varying the fixation material (TiCP and TiMo) and the rigid internal fixation (Champy and AO/ASIF) with a 3-D finite element analysis

• Grant number: 11/22627-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2012
• End date: January 31, 2013
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Eduardo Passos Rocha
• Grantee: Gustavo Barbosa de Oliveira
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

To analyze the mechanical behavior of bone after simulation of fracture of the mandibular angle and rigid internal fixation using plates and screws made from commercially pure titanium (TiCP) and an experimental titanium-molybdenum alloy (TiMo). In addition, two rigid internal fixation techniques will be analyzed: champy technique and AO/ASIF technique. Materials and methods: the tomographic image from a radiopaque physical replica of the mandible will be used to generate a geometric model similar to the physical replica with 13.0 Mimics software. The plates and screws will be modeled in the graphic design program SolidWorks v.2009 and adapted to the mandible. Thus, 4 geometric models representing part of the mandibular body, ramus, and mandibular angle with the fracture fixed with plates and screws will specify the following groups: group 1 - a segment of the mandibular angle fractured, with internal fixation by Champy technique, using plates and screws of commercially pure titanium (TiCP), group 2 - a segment of the mandibular angle fractured, with internal fixation by Champy technique, using a plate and screws of experimental titanium-based molybdenum alloy (Ti-Mo), group 3 - a segment of the mandibular angle fractured, with internal fixation by Association Osteosynthesis/Association for the Study of Internal Fixation (AO/ASIF) technique, using plate and screws of commercially pure titanium (TiCP), group 4 - a segment of the mandibular angle fractured, with rigid internal fixation by AO/ASIF technique, using plate and screws of experimental titanium-molybdenum alloy (TiMo). In all simulations, the cross-sectional area of the ramus will be fixed in the x, y, and z axes (x = y = z = 0). A distributed load of 200N will be applied to the occlusal surface of a mandibular first molar. The numerical analysis will be performed using the finite element software, Ansys Workbench 10.0.RESULTS: The results will be obtained using the von Mises equivalent stress (ÃvM) to the plates and screws, the maximum principal stress (Ãmax), minimum principal stress (Ãmin), and maximum principal strain (max) to the mandibular bone.(AU)