上颌埋伏并与侧切牙易位的尖牙的正畸矫治

Treatment of Maxillary Impacted Canine that Transposed with Lateral Incisor.

目的:探讨上颌埋伏并与侧切牙易位的尖牙的正畸矫治。方法:采用带钩的改良Nance弓联合直丝矫治技术治疗了2例替牙期上颌埋伏并和侧切牙易位尖牙病例,首先用改良Nance弓的末端钩在高位水平地牵引尖牙冠向颊侧及后方移动,同时用直丝弓技术使侧切牙排齐、根近中移动、牙体整体腭侧移动,使尖牙冠和侧切牙根在冠状向分开。然后采用“随形弓”,在维持两者在冠状向和垂直向的距离情况下,不断改变“随形弓”置于尖牙托槽上弓丝水平臂的第二序列弯曲,使两个交叉的易位牙体不断换位。结果:2例患者尖牙及侧切牙恢复正常的排列顺序,牙髓、牙周健康,治疗时间27个月。结论:矫治上颌埋伏并与侧切牙易位的尖牙关键是创造足够的空间,使两个易位牙的牙体换位时无干扰。改良Nance弓联合直丝矫治技术是一种有效的方法。

Objective： To explore the orthodontic treatment of maxillary impacted canine which is transposed with lateral incisor. Method： Two mixed dentition maxillary impacted canine that transposed with lateral incisor cases were treated by modified nance arch combined with straight wire arch. First, the canine crown was retracted buccally and distally with the hook of the modified nance arch at higher maxillary alveolus level, the lateral incisor root was moved mesially and tooth body was palately moved at the same time. The canine crown and root of lateral incisor could thus be separated in the coronal direction. Then, the ＂forming arch＂ was used to keep the coronal and vertical distance of two teeth, the second order bend of the arch wire on the transposed canine was changed continuously, the cross transposed teeth were corrected into normal order step by step. Results： Two maxillary impacted canine and transposition with lateral incisor cases were treated successfully after about 27 months treatment. The pulp and periodontal attachment were normal. Conclusion： The key to treat maxillary canine - lateral incisor transposition is to create sufficient space between the canine and the lateral incisor so that the transposed teeth are reordered to their normal position without interference. The combination of modified nance arch with straight wire arch technique is valid method.