0．021×0．025英寸方丝引起前牙唇舌向倾斜度变化的研究

Change of labiolingual inclination of anterior teeth with 0.021×0.025 inch rectangular arch wires

目的探讨在0．022×0．028＂的直丝弓托槽中先后使用0．019×0．025＂和0．021×0．025＂的方形弓丝对于前牙的唇舌向倾斜度所产生的影响。方法在20例非拔牙矫治患者中选出10例前牙唇舌向倾斜度欠满意的患者，对其使用0．019×0．025＂和0．021×0．025＂两种方丝时的头颅侧位片进行测量，对0．021×0．025＂的方丝引起的前牙唇舌向倾斜度的变化进行统计分析。结果将0．019×0．025＂不锈钢方丝更换为0．021×0．025＂方钛丝2个月后，其引起的代表前牙唇舌向倾斜度的测量指标的变化有统计学意义（P〈O．01）。结论在使用0．019×0．025＂不锈钢方丝后，换用0．021×0．025＂的方钛丝并使其有一定的作用时间，可以引起前牙唇舌向倾斜度的明显变化。

Objective To investigate the influence on labiolingual inclination of anterior teeth by using 0. 019 × 0. 025 inch and 0. 021 × 0. 025 inch rectangular arch wires in 0. 022-inch straight wire appliance system. Methods 10 patients whose labiolingual inclination of anterior teeth were not satisfied were selected from 20 nonextraction patients. Lateral cephalograms of patients when using 0. 019 × 0. 025 inch and 0. 021× 0. 025 inch rectangular arch wires were analyzed. Statistic analysis was conducted on the change of labiolingual inclination of anterior teeth caused by 0. 021 × 0. 025 inch rectangular nickel-titanium arch wires. Results Statistical significance（P〈0. 01） in the change of labiolingual inclination of anterior teeth between using 0. 021 × 0. 025 inch rectangular nickel-titanium arch wires and 0. 019 × 0. 025 inch rectangular stainless steel arch wires was found. Conclusion Significant change of labiolingual inclination of anterior teeth could be seen when 0. 021 × 0. 025 inch rectangular nickel-titanium arch wires were used for the two month period after 0. 019 × 0. 025 inch rectangular stainless steel arch wires.