不同力值前牵引上颌骨结合活动扩弓矫治器矫治替牙期骨性AngleⅢ类错畸形的疗效比较

Comparative Effects of Different Strength before Traction Maxillary Expansion Combined with Activity Bow Correcting Device on Corrected Osseous Class Angle Ⅲ Teeth Micromaxillary Deformity

目的:探讨利用轻力前牵引联合扩弓矫治器前牵引矫治替牙期骨性AngleⅢ类错形畸形的机制和临床效果。方法:选取本院正畸科诊治的替牙期骨性AngleⅢ类错畸形患者30例作为研究对象,按随机数字表法分为两组,每组15例。试验组采用轻力前牵引联合活动扩弓矫治器进行,根据患者的具体错畸形类型决定扩弓的方法,扩弓加力直至上后牙的舌尖接近下后牙的颊尖为止。上颌扩弓的同时进行前牵引,每侧施力约120～150 g,前牵引力的方向与牙合平面向下成15°角左右,两侧施力方向要平行,要求患者每天坚持戴12～l4 h。对照组采用传统的前牵引力联合扩弓矫治器治疗,每侧施力为400～500 g左右。两组患者治疗前、后常规拍摄头颅定位侧位片并进行X线头影测量分析,并进行比较。结果:试验组SNA角明显增大,平均增大2.5°,上颌骨向前方增加明显,下颌骨向下向后旋转并相对向后退缩,上下切牙舌倾、上下颌骨的位置关系变得协调,软组织侧貌由凹面型变为直面型或者轻度凸面型,对照组与其疗效相当。两组矫治前、后的X线投影测量的差值比较差异均无统计学意义(P>0.05)。结论:与传统前牵引力相比,轻力前牵引联合活动扩弓矫治器治疗替牙期骨性AngleⅢ类错畸形,同样可以获得良好的疗效,侧貌改善明显,患者更易于接受,疗效可靠,临床上易于开展。

Objective：To compare the orthopedic effects of light-force protraction（LFP）maxillary expansion combining activity bow correcting device in mixed dentition skeletal class AngleⅢmalocclusion patients.Method：30 patients mixed dentition skeletal class Angle Ⅲmalocclusion in our hospital were selected and randomly divided into two groups of 15 patients each. The experimental group adopted light force before drawing expansion bow and correcting device for joint activities,depended on the type of specific teeth micromaxillary deformity patients decided to enlarge the bow,the method of expanded arch strength until the back teeth on the tip of the tongue close to the back teeth of buccal tip. Pulled the front of bow maxillary expansion at the same time,applied pressure on each side of about 120-150 g, former traction with the teeth closed in the direction of the plane down into 15° angle left and right sides,pressure on both sides of the direction to parallel were applied,required patients to wear 12-14 h every day. The control group was used traditional traction joint expansion bow before correction treatment,applied pressure on each side about 400 -500 g. Before and after regular shooting head lateral positioning slice and X line head shadow of two groups were analyzed and compared. Result：After treatment,the experimental group’s SNA angle increased,the average increased 2.5°,upper jaw forward significantly increased,mandibular rotated backward and downward was relatively backward,the incised teeth lingual inclination,the position relationship between upper and lower jaw becomes harmonious,soft tissue side looks from concave type changed to face or slightly convex,the control group had a similar curative effect. Before and after the X-ray projection measurement of two groups difference were compared,the differences had no statistical significance（P〉0.05）. Conclusion：Compared with the conventional-force maxillary protraction,the light-force protraction combining removable rapid maxillary expansion treatment skeletal class AngleⅢmalocclusion in the mixed dentition can be carried on and had a significant effect.