安氏Ⅱ类1分类严重深覆盖错的双期矫治

Two phase treatment of an Angle Clam Ⅱ division 1 malocclusion with deep overjet: A cephalometric analysis after activator treatment

目的 对安氏Ⅱ类１分类严重深覆盖锗 进行双期矫治，了解第一期矫治的牙颌面结构变化情况。方法 应用肌激动器（Ａｃｔｉｖａｔｏｒ）和固定矫治器对１２例覆盖大于１０毫米的安氏Ⅱ类１分类错 作双期矫治，对Ａｃｔｉｖａｔｏｒ——矫治前后的头颅侧位片进行分析。结果ＳＮＢ角增加１．２５度，下颌基骨向前生长２．２９毫米，磨牙关系在矢状方向变化３．７５毫米，前牙覆盖由１２．４２毫米减少至５．６３毫米，上切牙向后移动２．２５毫米，下切牙向前移动２．５４毫米，下颌平面角无明显改变。结论 用Ａｃｔｉｖｓｔｏｒ安氏Ⅱ类１分类严重深覆盖错 进行第一期矫治后，颌骨和磨牙关系的Ⅱ类关系得到改善、前牙覆盖减小，主要是下颌向前生长以及下颌位置变化所致，而上切牙向舌侧移动和倾斜、下切牙轻微向唇侧倾斜对减小覆盖也有一定作用。

Objective To investigate the changes of Class Ⅱ division 1 malocclusion with deep overjet treated with Activator. Methods Twelve puberty Class Ⅱ division 1 patients with the overjet over 10mm, were treated with two-phase approach. The first phase utilized activator and achieved a Class Ⅰ molar relationship. The cephalograms were compared before-and-after treatment of Activator. Results After treatment, SNE increased 1.250 (P < 0.05), Pg/OLP increased 2.29mm(P< 0.01), is/OLP- ss/OLP reduced 2.25mm(P<0.05), ii/OLP- Pg/OLP increased 2.S4nim(P> 0.05), NSL- ML increased 0.540(P> 0.05). Conclusion The improvement of molar relationship was a result of mandible changes mainly. Overjet reduction resulted mainly from mandible change and partly from dental change.