The clinical investigation of Quad-Helix appliance in expanding narrow dental arch / 实用口腔医学杂志

objective: To evaluate the effect of Quad Helix appliance in expanding narrow dental arch. Methods: 12 cases were treated by Quad Helix appliance. The effect was evaluated by measurement of the dental arch. Results: The dental arch of all the patients was expanded in half a year.The width between the maxillary first molars increased by 8.95 mm, and the width between maxillary first premolars increased by 5.7 mm. The average time of expanding was 20.75 weeks, the expanding efficiency was 0.43 mm per week. Conclusion: Quad Helix is an effective orthodontic appliance for correction of narrow dental arch.