Department of Health Sciences, School of Dentistry, Magna Graecia University of Catanzaro, Catanzaro, Italy.
Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Mich.
Am J Orthod Dentofacial Orthop. 2024 Mar;165(3):321-331. doi: 10.1016/j.ajodo.2023.09.016. Epub 2023 Nov 27.
Skeletal stability after bimaxillary surgical correction of Class III malocclusion was investigated through a qualitative and quantitative analysis of the maxilla and the distal and proximal mandibular segments using a 3-dimensional voxel-based superimposition among virtual surgical predictions performed by the orthodontist in close communication with the maxillofacial surgeon and 12-18 months postoperative outcomes.
A comprehensive secondary data analysis was conducted on deidentified preoperative (1 month before surgery [T1]) and 12-18 months postoperative (midterm [T2]) cone-beam computed tomography scans, along with virtual surgical planning (VSP) data obtained by Dolphin Imaging software. The sample for the study consisted of 17 patients (mean age, 24.8 ± 3.5 years). Using 3D Slicer software, automated tools based on deep-learning approaches were used for cone-beam computed tomography orientation, registration, bone segmentation, and landmark identification. Colormaps were generated for qualitative analysis, whereas linear and angular differences between the planned (T1-VSP) and observed (T1-T2) outcomes were calculated for quantitative assessments. Statistical analysis was conducted with a significance level of α = 0.05.
The midterm surgical outcomes revealed a slight but significantly less maxillary advancement compared with the planned position (mean difference, 1.84 ± 1.50 mm; P = 0.004). The repositioning of the mandibular distal segment was stable, with insignificant differences in linear (T1-VSP, 1.01 ± 3.66 mm; T1-T2, 0.32 ± 4.17 mm) and angular (T1-VSP, 1.53° ± 1.60°; T1-T2, 1.54° ± 1.50°) displacements (P >0.05). The proximal segments exhibited lateral displacement within 1.5° for both the mandibular right and left ramus at T1-VSP and T1-T2 (P >0.05).
The analysis of fully digital planned and surgically repositioned maxilla and mandible revealed excellent precision. In the midterm surgical outcomes of maxillary advancement, a minor deviation from the planned anterior movement was observed.
本研究通过对正畸医生与正颌外科医生密切沟通后制定的虚拟手术方案（VSP）进行预测，并对 12-18 个月的术后结果进行三维体素基叠加的定性和定量分析，探讨了双颌外科矫正 III 类错（牙合）畸形后上颌骨及下颌远、近段的骨稳定性。
对 17 例患者（平均年龄 24.8 ± 3.5 岁）的术前 1 个月（T1）、术后 12-18 个月（中期 T2）锥形束 CT 扫描和 Dolphin Imaging 软件获得的虚拟手术计划（VSP）数据进行了二次数据综合分析。使用 3D Slicer 软件，基于深度学习方法的自动工具进行锥形束 CT 定位、注册、骨分割和标志点识别。生成色图进行定性分析，计算计划（T1-VSP）和观察（T1-T2）结果之间的线性和角度差异，进行定量评估。统计学分析的显著性水平为α=0.05。
中期手术结果显示，上颌骨的实际推进量略低于计划位置（平均差异 1.84 ± 1.50 mm；P=0.004）。下颌远段的重新定位是稳定的，线性（T1-VSP，1.01 ± 3.66 mm；T1-T2，0.32 ± 4.17 mm）和角度（T1-VSP，1.53° ± 1.60°；T1-T2，1.54° ± 1.50°）差异无统计学意义（P>0.05）。在 T1-VSP 和 T1-T2 时，下颌右侧和左侧支均有 1.5°以内的外侧移位（P>0.05）。
对完全数字化的计划和手术重定位的上颌骨和下颌骨进行分析，结果显示精度非常高。在中期上颌骨前徙的手术结果中，观察到与计划的前向运动有轻微偏差。
