四圈扩弓簧的临床应用及改良设计

目的：介绍四圈扩弓簧矫治器的原理、特点、改良设计及临床应用效果。方法：结合典型病例介绍四圈扩弓的簧的制作、戴人和调节以及改良设计。结果：通过病例分析发现经18个月的治疗，6宽度可扩大9.65mm,3宽度扩大5.20mm,6宽度扩大3.60mm,3宽度减少0.45mm。结论：四圈扩弓筑是一种性能良好，值得推广使用的扩弓矫治器。

The Clinical Application and Modification of the Quad Helix Appliance

Objective: The aims of this study are to investigate the working mechanism, the characteristics, the clinical application and the suggested modification of the Quad Helix appliance. Methods: A 7-year-old, female patient with Pierre-Rokin syndrome, who was preformed with palatorrhaphy at 21-month-old treated by using a Quad Helix appliance for one year. Results: After one-year treatment, the wide between the maxillary first molars increased 9 65mm, and the wide between maxillary canines increased 5 20mm. The wide between the mandibular first molars also increased 3 60mm, however the wide between mandibular canines decreased 5 20mm. Conclusion: The Quad-helix appears to be a successful Orthodontic appliance to expand the narrow maxillary or mandibular arches.