头帽肌激动器矫治恒牙期严重骨性Ⅱ类1分类错的初步研究

Clinical Study of Severe Skeletal ClassⅡDivision 1 Permanent Dentition Patient Treated with A Combined Headgear and Activator

目的探讨头帽肌激动器矫正恒牙期严重骨性安氏Ⅱ类1分类错颌面部硬组织变化及口外矫形力的作用。方法 7例恒牙期严重骨性安氏Ⅱ类1分类患者,年龄12.5～14.0岁,采用头帽肌激动器Ⅰ期矫正,对矫治前后的X线头颅侧位片进行测量分析。结果矫形力对上颌骨作用不明显,SNA角无统计学变化,但上颌磨牙后退2.7 mm(P<0.01),U1-Y减少2.9 mm(P<0.01),U1-SN减小1.8°(P<0.05),表明上齿槽骨接近整体后移。下磨牙前移2.2 mm(P<0.05),SNB增大2.3°(P<0.05),使上下磨牙关系由完全远中达到矫治后的轻度近中。SN-MP治疗前后差异无统计学意义(P>0.05),说明患者的垂直向得到了很好的控制。结论对已过发育高峰期的恒牙期严重骨性安氏Ⅱ类1分类患者可使用矫形力使上齿槽整体后移,从而与生长发育潜力不足而后缩的下颌骨协调,达到较稳定的磨牙中性关系和良好的面型,减轻固定矫正的难度。

Objective The aim of this study was to investigate the first phase treatment of severe skeletal Class Ⅱ division 1 permanent dentition patient with a combined headgear and activator,and to analyze the change of the hard tissues and the effect of the orthopedic forces.Methods Seven cases with severe skeletal Class Ⅱ division 1 permanent dentition（4 males and 3 females,aged from 12.5 to 14.0 years old with an average age of 13.3 years old） were treated with a combined headgear and activator.Pre-and post-treatment cephalometric analyses were used to evaluate the effects of treatment with a paired-samples T test.Results Orthopedic force did not significantly affect the mandible,and no significant change was found with the SNA,but the upper molars were moved backward 2.7 mm（P0.01）,U1-Y decreased 2.9 mm（P0.01）,U1-SN decreased 1.8°（P0.05）,which meant that almost the whole upper alveolar bone moved backward.The lower molars moved forward 2.2 mm（P0.05）,SNB increased by 2.3°（P0.05）,which changed relationship of the molars from totally distal to light mesial relationship.No significant change was found with the SN-MP,which meant the vertical situation was well controlled.Conclusion The retrusion of the mandible of the severe skeletal ClassⅡdivision 1 patients who have passed the peak of development can be treated with the orthopedic forces to move the whole of the upper alveolar bone backward to build a good relationship of the molars and a good profile,so as to reduce the difficulty of the fixed orthodontic treatment.