摘要
目的探讨拔除下颌第一磨牙或第二前磨牙,下颌第三磨牙自发性近中移动的相关影响因素.方法本研究用回顾性分析,纳入近中移动下颌第二磨牙以关闭第一磨牙或第二前磨牙缺牙间隙的患者38例,共51颗下颌第三磨牙.在正畸治疗前(T1)和已关闭拔牙间隙且第三磨牙被施力前(T2)拍摄曲面断层片,记录矫治前下颌第三磨牙的Nolla stage分期,对相关线距和角度的变化进行分析.线性回归分析探讨下颌第三磨牙自发性近中移动的影响因素.结果下颌第二磨牙后间隙增加(5.84±2.03)mm(P<0.001);下颌第三磨牙自发性近中移动(4.67±2.87)mm(P<0.001);远中直立2.90°±10.58°(P=0.026),垂直向变化(-1.27±2.43)mm(P<0.001).多因素回归分析显示,矫治前的第三磨牙Nolla stage分期越大(B=0.26,P=0.025),矫治中获得的磨牙后间隙越多(B=0.82,P<0.001),第三磨牙距离平面越近(B=-0.272,P=0.021),其自发性近中移动越大.结论正畸近中牵引下颌第二磨牙关闭拔牙间隙时,下颌第三磨牙会自发近中移动.发育更成熟、距离平面更近以及萌出间隙增加更多的下颌第三磨牙自发性近中移动更多.
Objective To investigate the influencing factors of spontaneous mesialization of mandibular third molar in orthodontic patients with extraction of mandibular first molar or second premolar.Methods A total of 38 patients with 51 mandibular third molars were included in this study.Panoramic radiographs were taken before orthodontic treatment(T1)and before the third molar was force applied(T2).The Nolla stage of mandibular third molar before orthodontic treatment was recorded,and the changes of relevant linear and angular measurements were analyzed.Factors associated with the amount of third molar mesialization were investigated using regression analyses.Results The posterior space of mandibular second molar increased by(5.84 dz 2.03)mm(F<10.001),the spontaneous mesialization of the mandibular third molar was(4.67+2.87)mm(P<C 0.001),the distal uprighting was 2.90°±10.58°(P=0.026)and the vertical change was(-1.27±2.43)mm(P<0.001).Multivariate regression analysis showed that the larger the Nolla stage of the third molar before orthodontic treatment(B=0.26,P=0.025),the more posterior molar space obtained during orthodontic treatment(B=0.82,P<C0.001)»and the closer the third molar to the occlusal plane(B=-0.272,P=0.021),the greater the spontaneous mesialization.Conclusions When the mandibular second molar is mesially protracted to close the tooth extraction space,the third molars will mesialise spontaneously.Greater third molar mesialization was observed when Nolla stage of the third molar was higher before treatment,and when the third molar was closer to the occlusal plane,and when more posterior molar eruption space was obtained.
作者
邹明媛
潘恩僦
弓国梁
余飞
林新平
Zou Mingyuan;Pan Enjiu;Gong Guo Liang;Yu Fei;Lin Xinping(Zhejiang Chinese Medical University,Hangzhou 310000,China;Department of Stomatology,The Second Affiliated Hospitals Wenzhou Medical University,Wenzhou 325027,China;Hangzhou Yaboyi Oral Clinic,Hangzhou 310000,China)
出处
《中华口腔正畸学杂志》
2021年第3期131-135,共5页
Chinese Journal of Orthodontics
关键词
第三磨牙
自发性移动
影响因素
Third molars
Spontaneous mesialization
Influencing factors
