亚历山大矫正技术减数矫治的稳定性研究

Posttreatment stability of four first bicuspid extraction cases treated with the Alexander technique——model analysis

目的探讨亚历山大矫正技术在拔牙矫治中的应用及其效果的稳定性.方法选择15例恒牙NFDC5患者(男8例,女7例),开始矫治时间10.3～16.2岁.设计减数4个第一前磨牙,采用亚历山大矫正技术,对矫治前(T1)、矫治后(T2)及保持结束后平均27.8个月的观察期(T3)内的模型进行测量.统计学处理采用配对t 检验.结果上下尖牙之间的宽度在保持后的回访期内分别减小0.37 mm和0.72 mm,但P>0.05;虽然上、下颌牙弓排列在回访期内分别有0.53 mm和0.98 mm的拥挤,但同样无统计学意义.由于内收前牙,矫治后的上、下颌牙弓长度明显减小(P<0.01),在回访期内分别增加0.28 mm和0.05 mm,但P>0.05.结论初步研究结果表明,亚历山大矫正技术中矫治器设计及其矫正理念有利于拔牙矫正后的稳定.但长期稳定性尚待进一步观察.

Objective To evaluate the posttreatment stability of four first bicuspid extraction cases with the Alexander technique. Methods Fifteen patients, 8 males and 7 females in the permanent dentition were selected. The age range of the patients was 10.3 to 16.2 years old. Four first bicuspids of every patient were extracted and all patients were treated with the Alexander technique. The study casts were taken before(T_1), after treatment(T_2) and 27.8 months averagely follow-up(T_3). Data were correlated by means of paired t tests. Results Although maxillary and mandibular intercanine widths were increased by 0.98 mm and 0.87 mm, respectively, during treatment, they were decreased by 0.37 mm and 0.72 mm, respectively, during follow-up period. Maxillary and mandibular crowding were increased by 0.53 mm and 0.98 mm, respectively, during follow-up period. No statistical significance were found. Upper and lower arch depth were decreased significantly due to retraction of anterior teeth and remained stable during follow-up period . Conclusions According to this study, the design of the Alexander appliance and the Alexander technique are helpful for stability of extraction therapy. Follow-up is still necessary to evaluate the long-term stability.