推杆式下颌前移矫治器的研制与临床应用

Fabricate and clinical application research of push rod-mandibular advancement appliance

目的 :评估推杆式下颌前移矫治器治疗生长期下颌后缩患者的颌骨和牙列变化。方法 :经方丝弓矫治器排齐上、下牙列后 ,用国产推杆式下颌前移矫治器对 8例生长发育期安氏II1下颌后缩儿童进行矫治 ,拍摄治疗前后头颅定位侧位片 ,进行测量和分析。结果 :推杆式下颌前移矫治器治疗 5 -7个月后 (平均 6个月 ) ,II类磨牙关系矫治为I类关系 ,深覆盖减少了 6.9mm ,下颌骨的变化最为显著 ,SNB增加了 2 .5° ,下颌升支高度 (Co -Go)下颌总长度 (Co -Pg) ,下颌体长度 (Go -Pg)以及Pg到OLp平面的距离分别增加了 3 .8mm、6.5mm和 3 .8mm。上颌骨的生长受到一定抑制 ,SNA由 82 .4°减少到 81.0°。ANB减少了 3 .7° ,Wits值减少了 1.7mm。结论 :经国产推杆式下颌前移矫治器治疗 ,促进了下颌骨生长 ,抑制了上颌骨生长 ,使下颌骨长度得以增加 ,再加上上颌牙列远中移动 ,下颌牙列近中移动 。

Objective:To analyze the skeletal and dental changes contributing to Class II correction in growing patients treated with the push-rod mandibular advancement appliance(prMAA). Method: The material consisted of 8 Class II division 1 malocclusion cases, which were treated with the domestic made prMAA. Result: After 5~7 months (average 6 months) of prMAA therapy, Class II malocclusal relationships were corrected to Class I occlusal relationships. Overjet correction-averaged 6.9mm.Mandible changed significantly. SNB degree increased 2.3°, mandibular ramas height (Co-Go), mandibular length (Co-Pg), mandibular body length (Go-Pg) and the distance from Pg to Olp plane increased 3.8mm、6.5mm、3.8mm respectively. The increase was significant in clinic. It also inhibited maxillary growth, which resulted in reduction of SNA degree from 82.4°to 81.0°. Sagital changes appeared with the decrease of ANB by 3.7° and that of Wits value by 1.7mm..Conclusion: The therapy of prMAA led to the increase of mandibular length, restraint of maxillary growth, including upper dentition distal movement and lower dentition mesial movement.