NiTi单力偶辅弓伸长伴龈下龋损前磨牙的临床研究

Clinical study of premolar extrusion with subgingival decayed defect by one-couple orthodontic NiTi auxiliary arch

目的 :研究Ni Ti单力偶辅弓伸长伴有龈下龋损的前磨牙的效果。方法 :选择邻面龋损达龈下2 mm以上的患者30例,第一前磨牙18例,第二前磨牙12例。将同侧第一磨牙、第二磨牙稳定连接后,设计单力偶矫治力系,利用Ni Ti节段辅弓进行牵引。使用SPSS 8.0软件包对所得数据进行t检验。结果:所有患牙龋损最底端均达龈上1 mm,向移动的距离为2.6~4.1 mm。牵引结束后,冠根比例为1.24±0.30,龈沟深度为(1.87±0.28)mm。患牙长轴与同侧第一磨牙长轴之间的交角在治疗前、后无显著差异(P>0.05),支抗牙咬合关系保持稳定。结论:Ni Ti单力偶辅弓可精确有效地牵引伸长伴有龈下龋损的前磨牙,该力系对支抗牙的影响较小。

PURPOSE： To evaluate the effect of one-couple orthodontic NiTi auxiliary arch on the premolar extrusion which had subgingival decayed defect. METHODS： A total of 30 cases with subgingival decayed defects over 2 mm under the proximal gingival margin were chosen including 18 first premolars and 12 second premolars. The first and second molars on the same side were connected steadily and the one-couple orthodontic force system was designed. The NiTi segmental arch was used to extrude the teeth. Student＇s t test was performed with SPSS 8.0 software package. RESULTS： All the defect margins were 1mm over the gingival margins and the extrusion distance was 2.6~4.1 mm. After extrusion, the crown-root ratio was 1.24±0.30, the depth of the gingival sulcus was 1.87±0.28 mm. There was no significant difference before and after treatment in the angle between the axis of the extruded teeth and that of the first molar （P〉0.05）. The anchorage teeth kept almost the same relationship with the opposite. CONCLUSION： One-couple orthodontic NiTi auxiliary arch could extrude the premolars with subgingival decayed defects effectively and precisely. The designed force system had little effect on the anchorage teeth.