一、临床资料我们自1995年1月以来,在就诊病人中,随机选择30例矫治后病人,用硬质钴铬合金铸造改良式无基托保持器,代替Hawley氏保持器来保持,其中男12例,女18例,年龄13-35岁之间。二、制作方法1、铸造部分设计:1连续卡环:从一侧双尖牙颊侧近中牙面起,向后延伸至对侧双尖牙颊侧 First, the clinical data We have since January 1995 in the treatment of patients, randomly selected 30 patients after correction, with hard cobalt-chromium alloy cast non-modified base holder, instead of Hawley's holder to maintain, in which male 12 cases, 18 females, aged 13-35 years old. Second, the production method 1, cast part of the design: a continuous ring: from the buccal side of the buccal side of the mid-dentition, extending back to the contralateral bicuspid buccal