门型个体化唇弓治疗上颌唇向易位阻生尖牙的临床效果研究

Clinical effect of a door shaped individualized dental archwire on the treatment of maxillary transposed ca-nines

目的探讨门型个体化唇弓对上颌唇向易位阻生尖牙移动的效果和该装置对易位尖牙的移动机制,为临床提供参考。方法共收集单侧唇向上颌尖牙易位病例8例,用门型个体化唇弓进行矫治。分别于矫治前(T1)和矫治中(T2)易位尖牙牙冠移动至与同象限正常邻牙邻接但偏唇侧位置时拍摄全口曲面断层片,测量牙尖点和根尖点到中线的位移变化及长轴角度变化,进行移动机制的研究。采用牙周探针测量易位尖牙和对侧正常尖牙探诊深度和颊侧临床牙冠高度进行矫治前(T1)、矫治后(T3)牙周变化评估。结果所有8颗易位尖牙均成功通过门型个体化唇弓移动到牙弓正常近远中位置,平均耗时(11.5±2.7)个月,总的矫治疗程(28.3±4.7)个月。T1~T2期牙尖位移8.1 mm,根尖位移1.5 mm,牙尖位移大于根尖位移(P<0.05),尖牙长轴发生17.5°倾斜。T1、T3期牙周测量指标探诊深度和颊侧临床牙冠高度测量差异均无统计学意义(P>0.05)。结论上颌唇向易位阻生尖牙通过门型个体化唇弓在偏唇侧位置移动是可行的和有效的,该装置对易位尖牙的位移方式是控制性倾斜移动。

Objective To discuss the effectiveness and mechanism for movement of maxillary buccally transposed canines by using a door-shaped individualized dental archwire mechanic and to provide a reference for clinicians.Methods Eight patients with unilateral maxillary transposed canines were enrolled.All patients were treated with door-shaped individualized archwires.Before treatment(T1)and after the crowns of the transposed canines were moved to the right buccal positions in the dental arch during the treatment(T2),orthopantomograms were taken both at T1 and T2 to compare the linear changes(distance changes of the crown and root apex)and angular changes to study the mechanisms of tooth movement.The probing depth and buccal crown height were measured using a periodontal probe to compare periodontal changes before treatment(T1)and after treatment(T3)between the transposed canines and contralateral canines.Results All eight transposed canines were successfully brought back to their normal dental arch position but were made more buccal by using the door-shaped individualized dental archwire,with a mean of(11.5±2.7)months.The average overall duration was(28.3±4.7)months.The crown distance changes of the canines from T1 to T2(8.1 mm)were greater than those of the root apexes(1.5 mm)(P<0.05).The mean angulation changes of the long axes of the ca-nines were 17.5°.There was no significant difference in the depth of periodontal measurement and buccal crown height measurement between T1 and T3(P>0.05).Conclusion The buccal movement of maxillary transposed canines under a door-shaped individualized dental archwire was effective and feasible.The movement pattern under this mechanism was controlled tipping.