Evaluation of stress changes in the maxilla with fixed functional appliances-A 3D FEM study.

Aim: To evaluate the stress changes in the maxilla during fixed functional appliance use using three-dimensional finite element method (FEM) stress analysis.

Settings And Sample Population: A three-dimensional finite element model of the maxilla was constructed using the images generated from the cone-beam computed tomography of a patient treated for Class II malocclusion with a fixed functional orthodontic appliance. The FEM was used to study the stress changes seen in the maxilla, which were evaluated in the form of highest von Mises stress and maximum principal stress before and after the application of fixed functional appliance.

Results: Higher areas of stress were seen in the model of the maxilla with the fixed functional appliance (140 MPa) compared to that in the resting stage (58.99 MPa).

Conclusions: An increase in the maximum principal stress and von Mises stress in the posterior regions of the maxilla and maxillary teeth was seen. The stresses seen were double than that without the appliance. A high distalization force on the maxilla was seen with the fixed functional appliance.