安氏Ⅱ类病例下颌第二前磨牙拔除后下牙列生理性漂移的三维模型分析  

Three-dimension model analysis for physiological drift of the mandibular dentition after extraction of mandibular second premolars of Angle class Ⅱ patients

作　　者：魏松[1] 李晶[1] 周彦恒[1] 

机构地区：[1]北京大学口腔医学院.口腔医院正畸科,北京100081

出　　处：《北京大学学报（医学版）》2013年第1期81-86,共6页Journal of Peking University:Health Sciences

摘　　要：目的:探讨正畸减数患者下颌第二前磨牙自行调整后牙弓变化特征。方法:回顾分析20例安氏Ⅱ类减数的上颌第一前磨牙和下颌第二前磨牙使用亚历山大托槽系统采用自行调整策略的病例,将患者自行调整前、后的下颌模型进行三维扫描、重建和测量,应用SPSS 16.0统计软件分析患者下牙列自行调整前、后的前牙不齐指数、牙弓宽度、Spee曲线深度以及拔牙间隙的变化情况。结果:下前牙不齐指数,下第一磨牙宽度,下牙弓长度,左、右拔牙间隙均减小[(12.70±3.28)mm vs.(8.82±2.69)mm,P<0.001;(41.21±2.48)mm vs.(40.54±2.23)mm,P<0.001;(24.63±3.19)mm vs.(22.12±2.97)mm,P<0.001;(8.06±0.48)mm vs.(4.17±1.51)mm,P<0.001;(8.13±0.95)mm vs.(4.14±1.98)mm,P<0.001],Spee曲线曲度和下牙弓前部长度增加[(2.14±0.75)mm vs.(2.65±0.88)mm,P<0.05;(15.88±2.86)mm vs.(17.55±2.33)mm,P<0.05],尖牙间宽度基本维持不变[(27.25±2.69)mm vs.(27.26±1.73)mm,P>0.05]。结论:下颌第二前磨牙拔除后自行调整有助于缓解下前牙的错位不齐和改善磨牙关系。Objective：To observe the self-adjustment of the mandibular dental arch after extraction of the second mandibular premolars. Methods： Mandibular dental casts of 20 Angle class 1I patients treated with extraction of lower second premolars and upper first premolars, bonded with Alexander appliance, were taken before （T1） and after self-adjustment （T2）. All the casts were laser scanned, Little index, curve of Spee, arch width, arch length and extraction spaces of casts were digitally measured and ana- lyzed with SPSS 16.0. Results： Little index,lower molar width, lower arch length and extraction spaces were reduced [（12.70±3.28） mmvs. （8.82±2.69） mm, P〈0.001;（41.21±2.48） mmvs. （40.54±2.23） mm, P 〈0.001; （24.63±3.19） mmvs. （22.12±2.97） mm, P〈0.001;（8.06± 0.48） mmvs. （4. 17±1.51） mm, P〈0.001;（8. 13±0.95） mm vs. （4. 1±1.98） mm, P〈 0.001 ] ,while the curve of Spee and anterior lower arch length were increased significantly[ （2. 14±0.75） mmvs. （2.65±0.88） mm, P〈0.05; （15.88±2.86） mmvs. （17.55±2.33） mm, P〈 0.05 ]. Width between lower canines remained the same [ （27.25±2.69 ）mm vs. （27.26 ± 1.73 ） mm, P 〉 0 . 05 ]. Conclusion： Severe crowding and Angle class lI molar relationship could be successfully relived with lower second premolar extraction followed by self-adjustment.

关 键 词：错[牙合] 安氏Ⅱ类 牙移位 正畸学 矫正 拔牙 成像三维 

分 类 号：R783.5[医药卫生—口腔医学]