拔除下颌第三磨牙矫治14～23岁骨性Ⅲ类错(牙合)的临床效果观察

目的 分析拔除下颌第三磨牙矫治骨性Ⅲ类错(牙合)畸形后患者牙(牙合)面的变化,探讨该矫治模式的适应证、疗效和临床意义.方法 选择处于生长发育减速期和结束期的骨性Ⅲ类错(牙合)畸形患者19例(女性16例,男性3例),拔除下颌第三磨牙,配合摇椅形弓和短Ⅲ类牵引技术矫治骨性Ⅲ类错(牙合)畸形.通过头影测量对患者治疗前后的骨骼和牙齿变化进行评估,并进行配对t检验.结果 治疗后下颌切牙和磨牙发生明显的舌向移动,下切牙至Y轴的距离由治疗前的65.96 mm减至治疗后的63.98 mm,向远中移动(1.98±1.36)mm.下颌第一磨牙至Y轴的距离由治疗前的43.00 mm减至治疗后的39.84 mm,向远中移动(3.16±1.23)mm.矫治后下颌第一磨牙向远中倾斜(12.37±6.81)°,前牙覆盖增加(2.75±1.65)mm,矫治前后差异有统计学意义(P<0.05).结论 拔除下颌第三磨牙配合摇椅形弓和短Ⅲ类牵引技术可明显远中移动下颌磨牙和切牙.

Abstract：

Objective To assess the skeletodental changes after extracting mandibular third molars in skeletal Class Ⅲ patients in both post-puberty and adult.Methods Nineteen skeletal Class Ⅲ patients in post-puberty or adult(16 female,3 male)successfully treated with extracting mandibular third molars were included in the study.Cephalograms were analyzed to assess the skeletal and dental changes before and after treatment.Paired t-test was performed for statistical analysis of the data.Results The results revealed that the main changes were upright[(12.37±6.81)°]and distal movement[(3.16±1.23)mm]of the mandibular molars,and retraction[(1.98 ±1.36)mm]of the mandibular incisors.There was a significant improvement in overjet[(2.75±1.65)mm].Conclusions The lower molars and incisors could be distalized significantly with extraction of the lower third molars.