Evaluation of stress distribution in maxilla, mandible, and glenoid fossa after Class III intermaxillary traction: A three-dimensional finite element analysis study

Aim: In this study, we aimed to evaluate the stress distribution on maxilla, mandible, and glenoid fossa after application of Class III intermaxillary anteroposterior orthopedic forces of 150, 250, and 400 gas applied to a three-dimensional (3D) model of the young human dry skull. Methods: A 3D finite element model was developed from the computed tomography images of a growing boy (age, 13 years). ANSYS (version 16.0) software used to simulate Class III force of progressively increasing intensity over maxilla, mandible, and glenoid fossa to quantify the biomechanical reaction with two components, direction and stress. Results: We quantified detailed changes in the maxillofacial sutures, dentition, mandible, and glenoid fossa with bone-anchored maxillary protraction (BAMP) to analyze their effects. Conclusions: As the force increases from 150, 250 to 400 g, stresses are increased on all structures associated except maxillary central incisor which show a decrease in the stresses. Although forces were for maxillary protraction, stress generated at the circummaxillary sutures was minimal. As with any other Class III force, stresses were distributed on whole of condyle, capsular ligament, and minimal at glenoid fossa. This suggests that BAMP has more of mandibular restraining effect.