Comparison of stress occurring in plate and surrounding tissues in fixation of fractures in different parts of mandible with titanium plate and carbon fiber reinforced polyetheretherketone plate systems by finite element method

Mandible is one of the bones that is exposed to the most trauma and fractures within the maxillofacial bones. Condyle, angle and symphysis parts of the mandible are the most sensitive anatomical regions in terms of fracture. Treatment of mandible fractures in craniofacial trauma patients is very important in order to functions such as occlusion, chewing, phonation and preventing sequelae as well as providing a satisfactory cosmetic appearance. The treatment of mandibular fractures with internal fixation has become more popular with the development of miniplate and screw systems and the understanding of biomechanical principles. The aim of this study is to compare the biomechanical performances of carbon fiber reinforced polymer plates and titanium plates in fractures developed in different parts of the mandible, with the finite element analysis.In our study, 4 mandible models with fractures in different regions were obtained by using finite element analysis. Eight different fixation models made using titanium alloy mini-plate and carbon fiber reinforced polyetheretherketone plates were examined using 3D modeling and finite element analysis technique under two different loading conditions, incisal biting and molar chewing. As a result of the applied forces, the stresses occurring in the cortical bone around the screw, condyle, plate and screws and the amount of displacement between fragments were investigated by finite element analysis and comparisons were made between groups. The stresses in the cortical bone around the screws were found within physiological limits in all groups. Von Mises stress values on screws and plates were observed to be lower in models which using CFR-PEEK plate. The highest Von Mises stress value was found in titanium mini-plates applied to the angle fracture, and the stress on the plates was found to be less than the value that would cause permanent deformation or breakage of the plate in all models. The displacement between fragments in the fracture region was less in titanium plates because of their higher rigidity.When the investigated biomechanical parameters are evaluated, CFR-PEEK materials which are very close to the elasticity of the cortical bone, seem suitable for the treatment of mandible fractures in order to eliminate the complications that develop due to mechanical differences between the fixation material and the bone. With this study, we believe that the effects of stress on the material used in plate and screw systems will be examined, and complications such as screw or plate losses due to high stress accumulation, infection, stabilization disorders in the fracture line will be reduced, contributing to healing and will shed light on new studies to be done in the future.