我们常用的活动矫治器一般由固位装置、作用力部分及基托组成。固位装置位于抗基牙上 ,有防止活动矫治器在口腔内脱位的作用 ,是主要的固位部分 ,临床上通常采用卡环作为主要固位装置。当乳牙因龋或其它原因造成牙冠缺损或缺失 ,或替牙期 ,恒牙初萌阶段 ,往往因牙齿的临床牙冠? Our commonly used activities appliances generally by the retention device, the force part and the base composition. Retaining device is located on the anti-abutment to prevent dislocation of the active appliance in the oral cavity. It is the main retention part, and the clasp is often used clinically as the main retention device. When deciduous teeth due to caries or other causes of dental crown defects or missing, or dentition, permanent teeth early adulthood, often due to the clinical crown of teeth?