恒牙早期Ⅲ类错上颌前方牵引的疗效观察

The effect of maxillary protraction in early permanent dentition

目的:评价恒牙早期骨性反患者使用上颌前方牵引器治疗的疗效,确定矫形治疗的合适时机。方法:18例面中部凹陷的恒牙早期安氏Ⅲ类骨性错患者,男11例,女7例,年龄10～13岁,平均11.5岁,均采用上颌固定前方牵引矫治器进行治疗。治疗前、后分别拍摄X线头颅侧位定位片进行测量分析,测量结果使用SAS6.12软件包进行统计学分析。结果:治疗后SNA增加2.06°(P<0.001),A点前移3.94mm(P<0.001),U1-SN增加6.97°(P<0.001),上前牙切点前移6.86mm(P<0.001);SNB减小1.39°(P<0.01),SN-MP增加2.64°(P<0.001),Y轴角增加2.42°(P<0.001),Pg点下降7.42mm(P<0.001)。上前牙前移6.86mm,其中骨性变化占57.43%,牙性代偿为43.57%。结论:恒牙早期应用上颌前方牵引矫治器治疗骨性Ⅲ类错患者,可以显著促进上颌骨的向前生长,使下颌骨生长方向转为向下,抑制下颌向前生长。

PURPOSE： To evaluate the effect of maxillary protration in skeletal anterior crossbite patients in early permanent dentition and determine the optimal timing for orthopedic treatment. METHODS： 18 patients （11 males and 7 females with a mean age of 1 l.Syears） with concave profile were treated with protraction headgear. For each patient lateral cephalogram was taken before and after treatment. Cephalometric analysis was carried out by using linear and angular measurements. Statistical analysis was performed using SAS6.12 software package. RESULTS： All subjects were treated to normal overjet. SNA was increased by 2.06°（P〈0.001） ,A point was protruded by 3.94mm（P〈0.001）, U1-SN was increased by 6.97°（P〈0.001）.SNB was decreased by 1.39°（P〈0.01）,SN-MP was increased by 2.64°（P〈0.001）,Y axis was increased by 2.42°（P〈0.001）, Pg point was decreased by 7.42mm（P〈0.001）. Maxillary incisor was promoted by 6.86mm, which was a result of 57.43% skeletal change and 42.57% dental change. CONCLUSIONS： Maxillary protraction can significantly promote maxillary growth, change mandibular growth direction and inhibit mandibular protrusion in early permanent dentition.