微螺钉直接支抗直立下颌第二磨牙的临床研究

目的 评价微螺钉直接支持的片段弓矫治器直立下颌第二磨牙的效果.方法 本研究包括18例种植修复前正畸患者,平均年龄32.8±5.7岁.样本人群总计有25颗下颌第二磨牙近中倾斜,需要正畸直立治疗.所有患者经牙周专科医师检查不存在活动期牙周病.18例患者在其下颌前磨牙区植入一颗微螺钉(1.6×9.0mm,慈北医疗器械有限公司),植入高度在膜龈结合部位或稍偏向方.愈合一周后,微螺钉头部连接由0.016×0.022英寸(1英寸=25.4 mm)的TMA丝制作的磨牙直立片段弓丝.下颌第二磨牙远中直立治疗前后分别拍摄头颅侧位定位片,并进行头影测量的分析比较.结果 18例患者的25颗近中倾斜的下颌第二磨牙均获得良好的正畸直立治疗效果,直立治疗的平均时间为4.0±1.0个月.相对于下颌平面,第二前磨牙的角度和高度均未发生变化.而第二磨牙角度平均增加16.5度(P＜0.001),第二磨牙和第二前磨牙距离平均增加4.4 mm(P＜0.001),均有显著性意义.第二磨牙远中颊尖高度未发生显著性变化.结论 应用微螺钉直接支抗支持的TMA丝片段弓矫治器可以有效地远中直立下颌倾斜磨牙,支抗稳定,第一磨牙间隙适度扩大.

Uprighting mesially inclined mandibular second molars with direct miniscrew anchorage

Objective The purpose of this study is to evaluate the effectiveness of the segmented arch technique with direct miniscrew anchorage for uprighting mesially inclined mandibular second molars.Methods The sample comprised 18 implant-prosthodontic patients(aged 32.8±5.7 years).There were 25 mesially inclined mandibular second molars that need to be uprighted before implant denture therapy.The periodontal treatments were performed before orthodontic treatment if necessary.One miniscrew (1.6 × 9.0 mm,self-drilling screw;CiBei Co.,Ningbo,China) was placed between the mandibular premolars around mucogingival junction level.After a week,the segmented arch (0.016 × 0.022 inch TMA) was developed and cantileverly mounted on the miniscrews.The cephalometric radiographs before and after the uprighting treatment were measured and compared.Results All the inclined second molars have been uprighted.The average treatment period was 4.0± 1.0 months.After the treatment,the angle or distance between lower second premolar and the mandibular plane did not change significantly,while the angle of the mandibular second molar was significantly increased by 16.5 degree (P＜0.001).The distance between the lower second premolar and second molar was significantly increased by 4.4 mm (P＜0.001).The distal-buccal cusp of the lower second molar did not extruded significantly.Conclusions The segmented arch technique with direct miniscrew anchorage could be used as an efficient method to upright inclined molars,and the first molar space can increase moderately.