[A study on alveolar ridge augmentation guided by orthodontic forced eruption in patients with severe periodontitis].

Objective: To evaluate the clinical effect of alveolar bone augmentation in teeth with severe periodontitis using orthodontic forced eruption. Methods: Twelve patients (5 males and 7 females) with severe periodontitis and malocclusion who visited the Department of Orthodontics and Department of Periodontology, Peking University School and Hospital of Stomatology from October 2018 to May 2022 were included in this retrospective study. The age was (38.8±6.6) years (24-49 years). A total of 16 maxillary incisors that could not be retained due to severe periodontitis were included. The orthodontic fixed appliance was used to extrude the teeth. Cone-beam CT (CBCT) images of the patients before and after orthodontic forced eruption were collected. The voxel-based registration was used to superpose the images before and after orthodontic forced eruption. The height, thickness, and apical alveolar bone area were measured on the sagittal plane. The alveolar bone volume before and after orthodontic forced eruption was measured using three-dimensional reconstruction technique, and the influencing factors related to the alveolar volume change were analyzed. Results: The results of this study showed that the eruption distance of the teeth was (2.37±0.82) mm, and the alveolar bone height increased by (1.11±0.79) and (0.98±0.79) mm (t=3.73, P=0.010; t=4.85, P<0.001). The proximal and distal alveolar bone height increased by (1.10±0.78) and (0.86±1.08) mm, respectively (t=5.59, P<0.001; t=3.18, P=0.006). The alveolar bone thickness decreased (0.30±0.31) mm (t=-3.75, P=0.002) and alveolar bone area increased (6.84±5.86) mm2 (t=3.71, P<0.001). The alveolar bone volume increased (53±49) mm3 (t=4.38, P<0.001). The alveolar bone volume was moderately positively correlated with eruption distance, apical and mesial alveolar bone thickness (r=0.55, P=0.028; r=0.63, P=0.008; r=0.67, P=0.005). Conclusions: Orthodontic forced eruption results in a favorable increase of the alveolar bone in the upper incisor that cannot be retained due to severe periodontitis, which provides better periodontal hard tissue conditions for subsequent dental implant.目的： 评价正畸伸长重度牙周炎患牙引导牙槽骨增量的临床疗效。 方法： 回顾性纳入2018年10月至2022年5月于北京大学口腔医学院·口腔医院正畸科及牙周科就诊的12例牙周炎伴错(牙合)畸形患者资料（男性5例，女性7例），年龄（38.8±6.6）岁（24~49岁），共16颗因重度牙周炎致无法保留的上切牙。使用正畸固定矫治器对患牙进行正畸伸长，收集正畸伸长前后锥形束CT影像资料。使用体素重叠技术对同一例患者两时点锥形束CT影像进行叠加，在矢状面上测量牙槽骨高度、厚度及牙槽骨根尖区面积，使用三维重建技术测量正畸伸长前后牙槽骨改建体积，并分析与牙槽骨改建体积相关的影响因素。 结果： 患牙伸长距离为（2.37±0.82）mm。正畸伸长后，唇侧和舌侧牙槽骨高度分别增加（1.11±0.79）和（0.98±0.79）mm，近中和远中侧牙槽骨高度分别增加（1.10±0.78）和（0.86±1.08）mm，根尖区牙槽骨厚度减少（0.30±0.31）mm，牙槽骨根尖区面积增加（6.84±5.86）mm2，牙槽骨改建体积为（53±49）mm3。牙槽骨改建体积与牙齿伸长距离、根尖区及近中侧牙槽骨厚度呈中度正相关（r=0.55，P=0.028；r=0.63，P=0.008；r=0.67，P=0.005）。 结论： 对重度牙周炎致无法保留的上切牙进行正畸伸长治疗，可有效获得牙槽骨增量，为后续种植修复提供良好的牙周硬组织条件。.