改良Nance弓在矫治上颌腭侧埋伏尖牙的作用

目的 探讨改良Nance弓在矫治上颌腭侧埋伏尖牙时矫治力方向设计及支抗设计的作用.方法 7例单侧上颌腭侧埋伏尖牙均采用外科-正畸联合治疗.手术暴露埋伏尖牙牙冠,粘接舌侧扣;戴入改良Nance弓,利用改良Nance弓位于腭侧不锈钢丝上的附钩,先将尖牙冠向后牵引绕过侧切牙的牙根,直到位于正常尖牙间隙的腭侧,如尖牙间隙不足,则粘结上颌托槽,预备尖牙间隙;再采用直丝弓技术将埋伏尖牙向唇侧移动,排齐牙列,调整咬合关系.对治疗后牙齿的松动度、牙髓活力等进行观察.结果 7位埋伏尖牙均被牵引至牙弓的正常位置;牙髓活力测试正常,牙周附着良好.结论 改良Nance弓在矫治上颌腭侧埋伏尖牙时,在矫治力方向设计和支抗控制方面有独特优点和作用.

The effect of modified Nance arch on treating maxillary palatally impacted canines

Objective To investigate controlof anchorage and force direction of Modified Nance Arch on treating maxillary palatally impacted canines.Methods 7 maxillary unilateral palatally impacted canines all underwent surgery management and orthodontic treatment.After full flap closure,a lingual knot button was firmly bonded on the surfaces of the impacted canine crowns.The Modified Nach Arch was installed.The hook attached to the lingual stainless steel wire of the Archtracted the impacted canines backward across the root of the lateral incisor and to the palatal position of its normal clearance.If the space is not enough,the maxillary dentition will be bonded with brackets to create space.Then canine was moved labially by straight wire appliance.The condition of pulp and periodontal attachment were observed after treatment.Results 7 unilateral maxillary palatally impacted canines were tracted to normal position,the pulp condition and periodontal attachment are normal.Conclusions The Modified Nance Arch has unique advantages in treating maxillary palatally impacted canines on control of anchorage and force direction.