A Finite Element Analysis Of Maxilla Protraction Using Clear Aligners

To investigate the displacement and stress distribution of the maxilla and its sutures using clear aligners compared with fixed appliance during maxillary protraction by finite element analysis. A three-dimensional finite element model of the maxilla, incorporating sutures and periodontal membrane, was developed. A protraction force of 500 grams per side was applied using either clear aligners or fixed appliance, with the force directed in different orientations with respect to the occlusal plane. Group A: Clear aligner, 30°, B: Fixed appliance, 30°, C: Clear aligner, 0°, D: Clear aligner, 40°. Displacement and stress distribution were then analyzed. After the application of force, the stress was mainly concentrated at the zygomaticomaxillary suture and the zygomaticotemporal suture with the greater vertical and sagittal displacement. All groups exhibited forward displacement and counterclockwise rotations in the maxilla and maxillary sutures, and when compared to the fixed appliance group, the maxilla in the clear aligner Group A demonstrated a greater tendency towards total displacement. As the force direction increased from 0°, 30° to 40°, the displacements and counterclockwise rotations of the maxilla gradually decreased in the clear aligner groups. The combination of clear aligners and maxillary protraction should be considered to obtain proper stress and displacement values with maxillary hypoplasia. However, potential maxillary rotation should be carefully monitored to ensure optimal outcomes.