Changes In Occlusal In The Nasomaxillary Buttress After Orthodontic Treatment

to analyze the effects of extraction orthodontic treatment on the distribution of occlusal stress in nasomaxillary buttresses. We selected eligible patients and collected their pre- and post-orthodontic cone-beam computed tomography (CBCT) data. A three-dimensional model of the left part of the skull and maxillary teeth was constructed from the CBCT images using Mimics software, and load occlusal force and muscle force were applied to the model. Finite element analysis was performed in the Abaqus software by the same researcher using the same methodology. The stress distributions in the pre- and post-orthodontic models were similar and were mainly distributed from the dentition to the alveolar bone and maxilla, and upward to the frontal bone. Before treatment, the maximum stress (14 MPa) on the nasomaxillary buttress area was in the apical area of the canine. After treatment, the maximum stress distribution in the nasomaxillary buttress area shifted towards the pearly foramen, and the stress magnitude in the apical area of the canine decreased by approximately 10% (12.6 Mpa). Additionally, there was an increase in displacement in the nasomaxillary buttress area at posttreatment compared with pretreatment. This study confirmed the presence of occlusal distribution trajectories in the maxillofacial region, dominated by the nasomaxillary buttress area, and the occlusal stress distribution in this area changed significantly after orthodontic treatment .