Comparison of the effects of different types of maxillary protraction on the maxilla with finite element analysis
Aim: To compare the two different skeletal anchorage methods with finite element analysis in the treatment of Class III patients with maxillary retrognathia.
Material and Methods: Two different treatment scenarios were performed on the skull model obtained from computerized tomography images of skeletal Class III patients with maxillary retrognathia and finite element analysis was performed. In the first group; mini plates were simulated on the infra zygomatic crest. A unilateral 500 g protraction force was applied to the face-mask. In the second group; mini plates were simulated in the infrazigomatic crest and mandibular symphysis. Then, 500g protraction force was applied with Class III elastic between the miniplates. Von Misses stresses and displacement values were evaluated comparatively.
Results: In the Class III elastic group, maximum Von Misses stress occurred around the infra zygomatic crest and symphysis anchored with 0.078MPa. The maxillary posterior region and paranasal regions were the areas that showed the highest Von Misses tension after infra zygomatic crest and symphysis. In the face-mask group, the most common site of Von Misses stress in the nasomaxillary complex and alveolar structures were the infra zygomatic area where plaques were applied, followed by pterygomaxillary suture. Tensile forces are reduced especially in these two areas by spreading to the surrounding structures.
Conclusion: In both methods, it was determined that the amount of force transmitted to the circumaxillary sutures was sufficient to induce the formation of osteogenesis in these regions.
Keywords: skeletal anchorage, Class III malocclusion, finite element analysis. Continuous...