微钛钉种植体支抗在上颌前突正畸治疗中的临床应用

目的探讨微钛钉种植体支抗在上颌前突矫治中的临床应用及其与传统支抗的区别。方法选择上颌前突拔牙矫正的患者40例,随机分成实验组和对照组,每组20例。实验组使用微钛钉种植体作为支抗关闭间隙,对照组使用常规滑动法关闭间隙,治疗前后利用X线头颅片进行测量分析对比。结果所有病例矫治后,上前牙突度及轴倾度得到改善,拔牙间隙均关闭。实验组与对照组上中切牙切缘到Y轴距离（U1-Y）分别平均减少4.78mm与2.63mm,上中切牙长轴与前颅底平面形成的后下夹角（U1-SN）分别平均减少16.62°与13.75°,上、下中切牙长轴之间的夹角（U1-L1）分别平均增大20.86°与13.66°;两组治疗前后数值的差异均有统计学意义。而矫治后实验组U1-Y平均增大0.27mm,差异无统计学意义（P〉0.05）,对照组平均增大3.16mm,差异有统计学意义（P〈0.05）。结论微钛钉种植体支抗可避免上颌磨牙的前移,能为上颌前突畸形的矫治提供有效的支抗来源。

Clinical application of micro-implant for orthodontic anchorage in patients with maxillary protrusion

Objective To investigate the efficiency of micro-implant for orthodontic anchorage in patients with maxillary protrusion. Methods 40 patients with maxillary protrusion were randomly divided into two groups, with 20 patients in each group. Micro-implants were used in experimental group as the orthodontic anchorage to close the space, and traditional sliding technology was used in control group. Cephalometric radiographies were taken and analyzed before and after treatment. Results In all patients the protrusion and sagittal inclination of anterior teeth were improved significantly and the extraction space was closed. For the experimental and control group the average reduction of U1-Y was 4.78 mm and 2.63 mm, and U1-SN was 16.62° and 13.75°, respectively; The average increase of U1-L1 was 20.86° and 13.66° respectively. There was a significant difference before and after treatment in two groups. In U1-Y, the experimental group, there was no significant increase after treatment when compared to pre-treatment （0.27 mm, P 〉 0.05）, while significant difference was found for the control group （3.16 mm, P 〈 0.05）. Conclusions Micro-implant could be an efficient method to reinforce the orthodontic anchorage and avoid the forward movement of maxillary molar in the treatment of maxillary protrusion malocclusion.