上磨牙颊侧微种植体支抗在安氏Ⅱ类正畸减数拔牙患者垂直向控制中的作用

Efficacy of vertical control by using mini-implant anchorage in maxillary posterior buccal area for Angle classⅡextraction patients

目的:探讨常规上磨牙颊侧微种植体支抗技术对安氏Ⅱ类拔牙矫治病例垂直向控制中的作用。方法:对常规使用两颗上磨牙颊侧微种植体支抗的28例安氏Ⅱ类正畸减数拔牙患者进行治疗前后头颅侧位X线片的头影测量分析比较。结果:头影测量发现垂直向指标中,下颌平面角SN-MP平均减小1.40°±1.45°,FMA平均减小1.58°±1.32°;后前面高比(S-Go/N-Me)平均减小1.42%±1.43%;Y轴角平均减小1.03°±0.99°,面角平均增大1.37°±1.05°,差异均有统计学意义(P<0.001);上颌磨牙平均压低(0.68±1.40)mm,上前牙平均压低(1.07±1.55)mm,差异均有统计学意义(P<0.05),提示治疗后有一定的上磨牙压低,产生了一定的下颌平面逆时针前旋,对侧貌改善产生了积极影响。结论:常规上磨牙颊侧微种植体支抗有一定的垂直向控制能力,可以产生一定的下颌逆时针旋转,可更好地改善安氏Ⅱ类患者的侧貌。

Objective:To investigate the efficacy of vertical control by using conventional mini-implant anchorage in maxillary posterior buccal area for Angle classⅡextraction patients.Methods:Twenty-eight Angle classⅡpatients[9 males,19 females,and age(22.6±2.8)years]were selected in this study.All of these patients were treated by using straight wire appliance with 4 premolars extraction and 2 mini-implant anchorage in maxillary posterior buccal area.In this study,the self-control method was used to measure and analyze the lateral radiographs taken before and after orthodontic treatment in each case,the main cephalometric analysis items were related to vertical changes.The digitized lateral radiographs were imported into Dolphin Imaging Software(version 11.5:Dolphin Imaging and Management Solutions,Chatsworth,California,USA),and marked points were traced.Each marked point was confirmed by two orthodontists.The same orthodontist performed measurement on the lateral radiographs over a period of time.All measurement items were required to be measured 3 times,and the average value was taken as the final measurement result.Results:Analysis of the cephalometric radiographs showed that,for vertical measurements after treatment,the differences of the following measurements were highly statistically significant(P<0.001):SN-MP decreased by(1.40±1.45)degrees on average,FMA decreased by(1.58±1.32)degrees on average,the back-to-front height ratio(S-Go/N-Me)decreased by 1.42%±1.43%on average,Y-axis angle decreased by(1.03±0.99)degrees on average,face angle increases by(1.37±1.05)degree on average;The following measurements were statistically significant(P<0.05):the average depression of the upper molars was(0.68±1.40)mm,and the average depression of the upper anterior teeth was(1.07±1.55)mm.The outcomes indicated that there was a certain degree of upper molar depression after the treatment,which produced a certain degree of counterclockwise rotation of the mandibular plane,resulting in a positive effect on the improvement of the profile.Conclusion:The conventional micro-implant anchorage in maxillary posterior buccal area has a certain vertical control ability,and can give rise to a certain counterclockwise rotation of the mandible,which would improve the profile of Angle ClassⅡpatients.