早期远移磨牙矫治上颌第二前磨牙阻生的临床研究

Early orthodontic treatment of impacted maxillary second premolar by first molar distalization

目的:探讨远中移动上颌第一磨牙,结合直丝弓矫治伴有第二前磨牙阻生的II类错畸形的有效性。方法:选取处于替牙晚期、上颌中重度拥挤的24例患者,采用活动矫治器单侧或双侧远移上颌第一磨牙,开辟间隙并进行第二期固定矫治;统计学分析治疗前后的X线头影测量结果,评估临床疗效。结果:上颌第一磨牙平均远中移动4.5 mm,两侧磨牙和尖牙达到I类关系,上颌前牙唇倾度增加。结论:早期远中移动上颌第一磨牙并结合直丝弓技术可促进第二磨牙正常萌出。

Objective： To study the feasibility of distalization of maxillary first molar for the correction of class Ⅱ malocclusion with impaetion of second premolar. Methods： 24 subjects with crowding mixed late dentition and impacted second premolar were treated by distalization of maxillary first molar unilaterally or bilaterally with removable appliance and followed by straight wire appliance. Cephalometric analysis was performed with pre-treatment and post-treatment cephalograms. Paired t-test was conducted to assess the treatment effects. Results： The crowns of the maxillary first molars were distalized by an average of 4.5 mm into a Class Ⅰ molar and canine relationship, Labioelination of the maxillary anterion teeth increased. Conclusion： Malocclusions of class Ⅱ with impaction of second premolar can be treated by distalization of maxillary first molar with removable distalizing appliance and straight wire appliance in the mixed late dentition.