Changes in alveolar bone remodeling after maxillary anterior retraction using fixed appliances with different periodontal conditions: A retrospective study based on cone-beam computed tomography.

Abstract

Introduction: This study aimed to compare changes in maxillary anterior alveolar bone remodeling and complication rates in adult patients with different periodontal conditions after maxillary anterior tooth retraction using fixed appliances. In addition, this study analyzed potential factors affecting alveolar bone thickness in patients with periodontitis.

Methods: A total of 55 adult patients (mean age, 23.53 ± 4.55 years) with Angle Class I or II Division 1 malocclusion with maxillary protrusion were recruited and categorized into the healthy control group (n = 23), stage I periodontitis (P-I) group (n = 17), and stage II periodontitis (P-II) group (n = 15). The maxillary anterior teeth were retracted using a fixed appliance. Cone-beam computed tomography was used to measure the thickness, height, and density of the alveolar bone in the maxillary anterior region before (T1) and after (T2) treatment. The incidences of bone dehiscence and fenestration were documented. Statistical analysis was conducted to evaluate intergroup and intragroup differences. Clinical and cephalometric data were collected to identify factors affecting the changes in alveolar bone thickness using multivariate linear regression analysis.

Results: The labial alveolar bone thickness increased significantly after treatment in all groups, but no differences were observed among the groups. In contrast, the palatal alveolar bone thickness decreased, particularly in the P-I and P-II groups, at the midroot and apical levels (P <0.05). A significant decrease in alveolar bone height was observed in the P-I and P-II groups (P <0.05). The incidence of palatal bone dehiscence was higher in the P-II (84.44%) and P-I (69.61%) groups. Multivariate linear regression analyses revealed that sex, treatment duration, periodontal treatment, changes in tooth inclination, and initial thickness significantly affected palatal alveolar bone thickness changes in patients with periodontitis.

Conclusions: After retraction of the maxillary anterior teeth with a fixed appliance, the labial alveolar bone of the maxillary anterior teeth thickened, whereas the palatal bone exhibited thinning in adults with periodontitis. The reduction in palatal bone height was more significant in this population than in healthy subjects, along with a higher incidence of palatal bone dehiscence. Bone morphology must be carefully assessed, considering these relevant factors before and during orthodontic treatment.