拔除下颌第三磨牙矫治14～23岁骨性Ⅲ类错的临床效果观察

Orthodontic treatment of skeletal ClassⅢ patients with mandibular third molar extraction in both post-puberty and adult

目的分析拔除下颌第三磨牙矫治骨性Ⅲ类错拾畸形后患者牙猞面的变化，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类错猞畸形患者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类错拾畸形。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轴的距离南治疗前的65．96mm减至治疗后的63．98mm，向远中移动（1．98±1．36）nlm。下颌第一磨牙至Y轴的距离由治疗前的43．00mm减至治疗后的39．84mm，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。

Objective To assess the skeletodental changes after extracting mandibular third molars in skeletal ClassⅢpatients 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.