微种植体支抗矫正上颌牙弓不对称的临床研究

目的探讨微种植体支抗单侧推磨牙向后结合直丝弓矫治技术矫正上颌牙弓不对称的临床应用及疗效,同时与传统头帽口外弓(不对称面弓)进行比较。方法选择安氏Ⅱ类亚类错12例,随机分成A、B二组,A组采用微种植体支抗,植入位置在磨牙远中关系侧第一前磨牙与磨牙之间根方,4周后加力;将Ni-Ti螺旋弹簧压缩后置于上颌第一前磨牙与上颌第一磨牙之间,推磨牙远移,将磨牙远中关系侧推磨牙向后开展间隙的同时采用直丝弓矫治技术排齐整平牙弓,调整上颌中线,纠正不对称的上颌牙弓。B组用头帽口外弓(不对称面弓),4周后力值恒定为2.94~3.92 N。采用模型测量、头影测量分析观测其疗效。结果治疗组和对照组上颌单侧推磨牙3~9个月开展足够间隙后,所有病例磨牙均达到中性关系,结合直丝弓矫治技术,上牙弓均达到对称效果。实验组:上颌第一磨牙单侧平均移动距离4.55 mm,疗程3~5个月,平均移动速度1.27 mm/月,上颌第一磨牙长轴向远中倾斜角度为2.47°,磨牙旋转角度约1.18°,磨牙颊向移位0.93 mm,上颌中切牙唇舌向移动距离及长轴角度基本无改变。对照组:上颌第一磨牙单侧平均移动距离4.13 mm,疗程5~9个月,平均移动速度0.60 mm/月,上颌第一磨牙长轴向远中倾斜角度为2.36°,磨牙旋转角度约1.17°,磨牙颊向移位0.97 mm,上颌中切牙唇舌向移动距离及长轴角度基本无改变。结论两种方法在单侧推磨牙远移的过程中都发挥了强支抗的作用,未见前牙支抗丧失,结合直丝弓矫治技术,上牙弓均达到对称效果。但种植体支抗组不依赖于患者配合,疗效迅速,大大地缩短疗程。

The clinical study of correction of maxillary arch asymmetry by micro-implant anchorage

Objective To study the clinical application and therapeutic effect of correction of maxillary arch asymmetry by using micro-implant in unilateral molar distalization and straight wire appliance,and to compare with clinical application and therapeutic effect of traditional headgear bow(asymmetrical face bow).Methods 12 cases of angle-class Ⅱ malocclusion were chosen and divided into Group A and Group B equally at random.Patients in Group A were treated with micro-implant,which were implanted in the distal molar and in the alveolar bone between the roots of maxillary first premolar and maxillary first molar.The force was given after 4 weeks.The Ni-Ti coil spring compressed were placed between maxillary first premolar and the maxillary first molar in order to make the molar distalization.At the same time,straight wire appliance was used to flat the arch,and adjust the upper midline and correct asymmetry of the maxillary arch.The patients in B group were treated with headgear bow(asymmetrical face bow).Patients were given a constant force about 2.94-3.92 N after 4 weeks.The effect of two groups were observed and analyzed by model measurements and cephalometrics.Results After the unilateral molar distalization with enough space during 3 to 9 months,occlusal relationship of both groups were corrected to neutral relation.Combined with straight wire appliance,all the upper dental arch reached the symmetrical effect.In Group A,the treatment took 3-5 months,with unilateral maxillary first molar moving 4.55 mm on the average at the speed of 1.27mm/month.The angle of the maxillary first molar long axis tilted to the distal was 2.47 °.The rotation angle of molar was about 1.18 °.The molar moved 0.93 mm to the buccal.There was no significant change in the moving distance and the angle of the long axis in the maxillary central incisor.As in the Group B,the treatment took 5-9 months,with unilateral maxillary first molar moving 4.13mm on the average at the speed of 0.66mm/month.The angle of the maxillary first molar long axis tilted to the distal was 2.36°.The rotation angle of molar was about 1.17 °.The molar moved 0.97mm to the buccal.There was no significant change in the moving distance and the angle of the long axis in the maxillary central incisor.Conclusion In the process of the unilateral molar distalization,both two methods provide strong anchorage without losing the anterior anchorage.Combined with straight wire appliance,all the upper dental arch are symmetrical,but the implant group requires minimal patient compliance and shortens the whole treatment greatly.