上颌骨微型种植钉再次植入的成功率与风险因素分析

Success Rate and Risk Factors Associated with Mini-Implants Reinstalled in the Maxilla

目的为了确定两种在口腔中植入的正畸微型种植钉(OMIs)成功率的差异:初次植入的正畸微型种植钉(II-OMI)与再次植入相同类型的新种植钉(RI-OMI)的差异。方法此次研究对象由58位(19位男性,39位女性),平均年龄=21.78±5.85岁,为了在集体内收时形成强支抗在上颌后牙区颊侧的附着龈上至少接受过一个OMI(自攻型,2.0 mm上层直径和5 mm长度的圆锥形)的患者组成。如果植入一个OMI失败,新的一个会立即在邻近区域植入,或者在4到6周后再次植入在相同区域。最初植入的OMIs(II-OMI)总数为109个,再次植入的OMIs(RI-OMI)总数为34个。统计分析是用X2检验,生存率估计的乘积限法(Kaplan-Meier法),时序检验法(log-rank)以及COX比例风险回归模型完成的。结果成功率与平均持续时间分别是,II-OMI为75.2%和10.0个月,RI-OMI为66.7%和6.4个月。年龄,垂直骨面型以及植入位置与II-OMI和RI-OMI的成功率无关。时序检验显示植入在女性以及安氏III类错牙合的II-OMI更易失败。II-OMI在安氏III类错牙合的失败对照安氏I类错牙合的失败,相对风险为5.36(95%置信区间,2.008到14.31,P=0.001)。结论 II-OMI与RI-OMI的成功率没有统计学差异。性别与ANB角(上齿槽座点-鼻根点-下齿槽座点角)或许是能得到更好II-OMI结果的重要因素。

Objective To determine the difference in the success rate for two types of oral installed mini-implants （OMIs）. One type was initially installed OMI and the other type was new implant method （RI-OMI）. Methods The subjects consisted of 58 patients （19 male, 39 female; Mean age were 21.78 ± 5.85 years）who had received at leasi one OMI （self-drilling type,conical shape with 2.0-mm upper diameter and 5-mm length）in the attached gingiva of the upper buccal posterior regions for maximum anchorage during retraction. If an OMI failed,a new one was immediately installed in the same area after 4 to 6 weeks or in an adjacent area immediately. The total number of initially installed OMIs （II-OMI） was 109 and the total number of reinstalled OMIs （RI-OMI） was 34. Statistical analysis was performed using two tests, Kaplan-Meier method,log-rank test and Cox proportional hazards regression model. Results The success rate and mean duration were 75.2% and 10.0 months in II-OMI group, and 66.7% and 6.4 months in RI-OMI group. Age, vertical skeletal pattern, site and side of implantation were not related to the success rates of II-OMI and RI-OMI. Log-rank test showed that II-OMI in males and Class/II malocclusions were more prone to failure. The relative risk of II-OMI failure in Class III malocclusions was 5.36 compared with that in Class I malocclusions （95% confidence interval, 2.008 to 14.31, P=0.001）. Conclusion The success rate in II-OMI was not statistically different from that in RI-OMI. Gender and ANB angle might be more important factors for better II-OMI results.