Evaluating von mises stress distribution and deformation patterns in zygomaticomaxillary complex fractures- a finite element analysis study.

Abstract

Purpose: The ZMC provides essential midfacial support through its tetrapod configuration and current clinical practice lacks consensus on optimal fixation techniques for displaced fractures. This study compared stress distribution and deformation patterns across different ZMC fracture fixation methods to provide biomechanical guidance for clinical decision-making.

Methods: This finite element analysis (FEA) study was conducted using computer-generated ZMC models derived from CBCT scans of normal anatomy. Four distinct configurations were tested: intact ZMC (control), two-point fixation at frontozygomatic suture and buttress (FZ + buttress), two-point fixation at infraorbital rim and frontozygomatic suture (IOR + FZ), and three-point fixation incorporating all three sites. Standardized loading conditions (450 N occlusal force perpendicular to maxillary first molar and 150 N masticatory muscle force) were applied and material properties were defined by Young's modulus and Poisson's ratio for bone and titanium components. Comparative analysis of von Mises stress (MPa) and maximum deformation (mm) values was performed using Ansys (2019) software.

Results: The intact ZMC established a baseline. Two-point FZ + IOR fixation demonstrated the lowest stress values (0.25 MPa), while both two-point fixation. methods showed less deformation than three-point fixation. Three-point fixation exhibited the highest deformation (0.0066 mm) with elevated stress values (0.26 MPa), offering no significant advantage over two-point approaches.

Conclusion: FZ + Buttress fixation provides optimal stability against masticatory forces, while FZ + Infraorbital fixation offers balanced stability for minimally displaced fractures. Three-point fixation showed no advantage over two-point approaches despite additional hardware. These findings support a conservative surgical approach with minimal hardware for stable reduction, potentially reducing operative time, soft tissue dissection, and complications.