四圈簧扩大牙弓的长期效果(英文)

Long-term effect of quad helix expansion of dental arch

背景:快速扩大牙弓是快速扩大颌骨的有效方法,而与快速扩展相比,缓慢扩展稳定性更高,复发更少,但四圈簧扩弓的长期稳定性少见报道。目的:回顾性分析正畸临床中四圈簧扩大牙弓的临床效果。方法:混合牙列期及恒牙列早期牙弓狭窄患者22例使用四圈簧扩大牙弓至少3mm,在扩大牙弓之前(T1期)、Ⅰ期四圈簧扩弓治疗完成或整个治疗结束(T2期)及治疗完成后2年(T3期)分别制取牙齿石膏研究模型并摄取头颅后前位片,在模型上测量两侧第一恒磨牙之间距离,在后前位片上描点(J点)测量两侧基骨间距离及磨牙倾斜度,评价牙弓扩大的矫正及矫形效果。结果与结论:与扩弓前相比,四圈簧扩弓治疗后患者第一恒磨牙倾斜度和两侧基骨间距离逐渐减小;而四圈簧扩弓治疗后相比,随访2年时,患者两侧第一恒磨牙间距离、第一恒磨牙倾斜度和两侧基骨间距离的差异无显著性意义(P>0.05),提示四圈簧扩大牙弓的长期效果是稳定的,并有矫形效果。

METHODS： Twenty-two subjects with dental arch stenosis in mixed dentition and early permanent dentition who experienced an expansion of at least 3 mm with quad helix appliance were selected for this study. Plaster dental casts and posteroanterior radiographs were evaluated at the beginning of the treatment （T1）, at the completion of phase I quad helix expansion or full treatment （T2）, and approximately 2 years following the completion of treatment （T3）. The distance between two first molars was measured on the model. J point was drawn on the posteroanterior radiograph in order to measure the distance between the bilateral base bones and the molar inclination, as well as to evaluate the corrective and orthopedic effects of dental arch expansion. RESULTS AND CONCLUSION： Compared with that before expansion, the first permanent molar inclination and the distance between base bones on two sides were significant increased after quad helix expansion; there were no significant differences in the distance between two first permanent molars, first permanent molar inclination and the distance between bilateral base bones on two sides when compared after quad helix expansion and after 2-year follow-up （P 〉 0.05）. The results indicate that the long-term effect of quad helix expansion is stable with orthopedic effect.