拔牙矫治对恒牙早期下颌第二磨牙近远中向倾斜度的影响  

Effects of orthodontic extraction on mesiodistal angulation of lower second molars in patients with early permanent dentition correction

作　　者：刘俊峰 王新琼 张文忠 李嫕婧 张雄 赵转浓 盘月梅 LIU Junfeng;WANG Xinqiong;ZHANG Wenzhong;LI Yijing;ZHANG Xiong;ZHAO Zhuannong;PAN Yuemei(Department of Orthodontics,Stomatological Hospital,School of Stoma-tology,Southern Medical University,Guangzhou 510280,China;不详)

机构地区：[1]南方医科大学口腔医院(口腔医学院)口腔正畸科,广州510280 [2]南方医科大学口腔医院(口腔医学院)牙体牙髓科,广州510280

出　　处：《实用医学杂志》2024年第13期1833-1839,共7页The Journal of Practical Medicine

基　　金：广东省援疆农村科技(特派员)项目(编号:KTP20190282)。

摘　　要：目的探讨恒牙早期拔牙矫治患者下颌第二磨牙(lower second molar,L2M)近远中向角度自发变化与个体临床特征间的关系,为正畸医生的临床工作提供理论指导。方法经筛选共44例患者88颗下颌第二磨牙的近远中倾斜角度数据纳入本研究。根据治疗前L2M牙冠近远中倾斜角度(L2M初始角度)频数分布直方图,将其分为3组:A组:小角度组,L2M初始角度为0°~17.5°;B组:中角度组,L2M初始角度为17.5°~42.5°;C组:大角度组,L2M初始角度为42.5°~60°;根据L2M是否破龈且暴露大部分牙冠分为已萌组、未萌组。根据下颌平面角大小分为高角、低角、均角。利用CBCT重建全景片测量L2M的近远中倾斜度,分析各分组与L2M近远中倾斜角度变化间的关系。结果小角度组、大角度组、未萌组及高角组治疗后L2M近远中角度变大,而中角度组治疗后角度变小,差异有统计学意义(P<0.05)。已萌组及均角组治疗后L2M近远中角度变化不大,差异无统计学意义(P>0.05)。ANB角、Y轴角及下颌平面角与L2M的初始角度均无相关性。结论大角度、高角患者的L2M在矫治过程中更容易近中倾斜。L2M存在向正常轴倾度靠拢的发展趋势。Objective This study aimed to explore the relationship between the spontaneous changes of mesiodistal angulation of lower second molars(L2M)and individual clinical characteristics in patients with early permanent dentition correction.Methods A total of 44 patients with a total of 88 mandibular second molars were included in this study after screening.Based on the frequency distribution histogram of the initial angle of inclina-tion(L2M initial angle)of the L2M crown before treatment,it was divided into three groups:Group A:small angle group,L2M initial angle is 0°~17.5°;Group B:medium angle group,L2M initial angle is 17.5°~42.5°;Group C:large angle group,L2M initial angle is 42.5°~60°.According to whether L2M has erupted and exposed most of the crown,it was divided into erupted group and unerupted group.According to the mandibular plane angle,it can be divided into high angle,low angle,and average angle.CBCT reconstructed panoramic images were used to measure the mesiodistal inclination of L2M and analyze the relationship between each group and the change in mesiodistal inclination angles of L2M.Results After treatment,L2M mesiodistal angulation in the small angle,large angle,non-eruption,and high angle groups became more significant.The angle in the middle angle group was significantly smaller.The L2M mesiodistal angulation in the eruption and average angle group did not change significantly.The angles of ANB,Y-axis,and mandibular plane have no correlation with the initial angle of L2M.Conclusion The L2M in patients with large and high angles is more likely to topple during a correc-tion.During the correction,the L2M tends to approach the normal axial inclination.

关 键 词：恒牙早期 下颌第二磨牙 近远中向倾斜度 

分 类 号：R783.5[医药卫生—口腔医学]