拔牙和非拔牙矫治对颊廊影响的研究

The Effect of Extraction and Nonextraction on Buccal Corridors in Orthodontic Treatment

目的研究拔牙和非拔牙矫治对颊廊的影响。方法随机选取安氏Ⅰ类错拔牙矫治患者和不拔牙矫治患者各25例,在其矫治前后的牙模型上,分别对上下尖牙区和磨牙区唇颊面最突出的位置进行牙弓宽度的测量,同时在其矫治前后面部正位像上,测量笑容宽度和上颌可见牙列宽度,计算颊廊系数。所有数据均经统计学分析。结果非拔牙组矫治前后牙弓宽度变化无统计学意义。拔牙组矫治后上、下颌尖牙间宽度分别增加了2.87 mm和1.30 mm(P<0.05),但上下颌磨牙间宽度的变化无统计学意义。两组治疗前后颊廊系数变化均无统计学意义。结论对于安氏Ⅰ类错患者,拔牙和不拔牙矫治对颊廊均无明显的影响。

Objective To investigate the effect of extraction and nonextraetion on the bueeal corridors in orthodontic treatment. Methods Twenty-five Class I malocclusion patients treated by extraction of 4 first-premolar and 25 patients treated without tooth extraetions were included in the current study. The arch width was measured between the outmost labial aspect of the buccal surfaces of the canines and the molars on the pre-treatment and post-treatment study models. The ratio of visible maxillary dentition width to smile width changed were determined by measurement on the smiling pictures taken before and after treatment. All the measurements were compared statistically. Results In nonextraction group, there were no statistical differences in both anterior and posterior regions of mandible and maxilla between pre-treatment and post-treatment. In extraction group, lower anterior arch width of post-treatment was 1.30 mm larger than that of pre-treatment （ P 〈 0.05） and upper anterior arch width of post-treatment was 2.87 mm larger than that of pre-treatment （ P 〈 0.05）. There were no statistical differences in ratio of visible maxillary dentition width to smile width in both groups between pre-treatment and post-treatment. Conclusion For the Class 1 patients, the extraction treatment does not effect the buccal corridors.