Evaluation of osteogenic effects following alveolar bone augmentation with corticotomy.

[OBJECTIVE] Alveolar bone augmentation with corticotomy is commonly used in orthodontic treatment for patients with insufficient alveolar bone, which can increase the amount of alveolar bone, facilitate and accelerate tooth movement. However, its long-term osteogenic effect is seldom reported. This study preliminarily investigated the osteogenic effects following alveolar ridge augmentation using two types of bone grafts through three-dimensional radiographic evaluation and histomorphometric analysis.

[METHODS] First, 50 cases of malocclusion associated with alveolar bone defects were enrolled in this study. All patients underwent alveolar bone augmentation corticotomy and orthodontic treatment. According to different bone graft materials, patients were randomly divided into 2 groups, Rebone group and Bio-oss group. Cone-beam CT was used to measure alveolar bone-related parameters on: preoperatively(T0), 2 weeks postoperatively (T1), and 6 months postoperatively (T2) respectively. Analyze imaging data using paired t-test and repeated-measures analysis of variance (ANOVA). Next, bone tissue specimens were collected from the intraoperative bone cross-sections during genioplasty. These samples were obtained from patients who had undergone alveolar bone augmentation using two types of bone graft materials six months ago. Stained with HE, Masson, IHC, and VG methods respectively, the images were analyzed using Image-Pro Plus 6.0 software. One-way ANOVA (was applied to determine overall significance, followed by Bonferroni-corrected post-hoc analysis.

[RESULTS] Labial bone thickness was significantly increased (AT and MT,  < 0.001 compared to T1), and early bone remodeling was promoted (as indicated by a significant decrease in CTg values over time,  < 0.001). Compared to the control group, both graft material groups demonstrated favourable osteogenic capacity. The Rebone group showed no significant differences in new bone formation (percentage of red-stained area in Masson staining: 31.08% vs. 32.70%,  = 1.000) or OCN expression (OCN MOD value: 0.82 vs. 0.86,  = 0.930) when compared to the control. The Bio-Oss group exhibited lower levels of new bone formation (20.00% vs. 32.70%,  = 0.004) and reduced OCN expression (0.70 vs. 0.86,  = 0.004) relative to the control group.

[CONCLUSION] Corticotomy-assisted alveolar ridge augmentation significantly increases labial bone volume, effectively preserves dental tissues, and reduces orthodontic complications. Radiographic and histological analyses consistently demonstrated a strong capacity of the augmentation procedure to guide new bone regeneration and repair bone defects.

[TRIAL REGISTRATION] Chinese Clinical Trial Registry, ChiCTR-INR-17,012,749, 20 September 2017.