Effect of gonial angle variation on stress distribution and fracture susceptibility in the mandibular angle: a finite...

The mandibular angle is affected by morphological and functional factors. This study aimed to evaluate the stress distribution and susceptibility to fracture in the angle region under two different traumatic loading conditions in mandibular models with different gonial angles using finite element analysis.

A mandible model with three different gonial angles (115°, 125°, and 135°) was created based on a standard reference representing human anatomy. In the linear static analysis, a traumatic force of 2000 N was applied to a 1 cm diameter circular contact area in two different loading scenarios: (i) frontally, perpendicular to the coronal plane, and to the symphysis region, and (ii) laterally to the angulus region. The finite element analysis was performed on a workstation with an Intel^® Xeon™ 2.4 GHz processor and 48 GB of RAM. Mimics was used for segmentation, HyperMesh for mesh generation, Abaqus/Standard for analysis, and Abaqus/CAE for visualization of the results.

In both loading scenarios, as the gonial angle increased (115° → 125° → 135°), the stress concentration in the mandibular angulus region decreased. The highest stress values were found in the 115° model, whereas the lowest values were found in the 135° model. When the principal stress and Von Mises analyses were evaluated together, a more pronounced stress concentration was observed in the angulus region in models with a narrower gonial angle.

Within the limitations of this finite element analysis study, lower gonial angle models demonstrated higher stress concentrations in the mandibular angulus region under the simulated loading conditions. These findings suggest a potential biomechanical tendency toward increased stress localization rather than a direct prediction of clinical fracture risk. Further experimental and clinical studies are required to validate these observations and determine their clinical significance.