本文旨在比较方丝弓矫正器对Ⅱ类1分类错(牙合)拔牙和不拔牙患者覆盖,覆(牙合)的矫治效果。选择40名Ⅱ类1分类错(牙合)患者,磨牙关系为起始Ⅱ类、覆盖不小于6mm,覆(牙合)不小于半个上中切牙冠。保存患者矫治前、保持前、及保持2年后的模型及头颅定位片,20名拔除4个第一双尖牙,余20名不拔牙,在矫治过程中用相同的方丝弓矫正器.拔牙及不拔牙患者的选择依据临床经验,病例及头 The purpose of this article is to compare the orthodontic effects of square wire braces on the coverage and overbite of patients with category 1 malocclusion and without extracavity. Forty patients with Class Ⅱclass 1 malocclusion were selected. The molar relationship was initial type Ⅱ, covering not less than 6mm and covering more than half of the upper incisor crown. Preoperative patients to maintain before and after preservation, and maintain 2 years after the model and cranial positioning films, 20 were removed four first bicuspid teeth, more than 20 non-extraction of teeth, orthodontic treatment in the process using the same square arch. The choice of tooth extraction and non-extraction of patients based on clinical experience, cases and head