Comparison of biomechanical behaviour of maxilla following Le Fort I osteotomy with 2- versus 4-plate fixation using 3D-FEA: Part 2: Impaction surgery

The aim of the second part of this study was to evaluate the mechanical behaviour of 2- versus 4-plate fixation and bony structures after Le Fort I impaction surgeries using three-dimensional finite element analysis (3D-FEA). Two 3D-FEA models were created to fixate the impacted maxilla at the Le Fort I level as 2-plate fixation at the piriform rims (IMP-2 model) and 4-plate fixation at the zygomatic buttresses and piriform rims (IMP-4 model). The IMP-2 model contained 225 664 elements and 48 754 nodes and the IMP-4 model consisted of 245 929 elements and 53 670 nodes. The stresses in each maxillary model were computed. The models were loaded on one side, at the molar–premolar region, in vertical, horizontal and oblique directions to reflect the chewing process.It was concluded that the use of 4-plate fixation following Le Fort I advancement surgery provides fewer stress fields on the maxillary bones and fixation materials than 2-plate fixation from a mechanical point of view.