功能性安氏Ⅲ类错早期治疗后牙弓间隙变化

Arch length change after early treatment of pseudo Class Ⅲ malocclusion

目的 比较替牙期及恒牙期治疗功能性安氏Ⅲ类错牙合对牙弓间隙变化的影响。方法 治疗组包括替牙早期治疗的 2 5例功能性安氏Ⅲ类错牙合患者 ,平均治疗时间为六个月。对照组包括恒牙期治疗的 15例功能性安氏Ⅲ类错牙合患者。追踪组包括 18例患者 ,为治疗组完成治疗后 ,经过三年追踪的病例。治疗组 ,对照组和追踪组在替牙期及恒牙期拍摄头颅侧位片并取研究模型。对于每个测量项目计算均值和标准差 ,采用配对t检验统计治疗组治疗的变化。Mann -Whitney检验以比较追踪组与对照组之间的差异。 结果 治疗组治疗前后的模型分析表明 ,上颌牙弓获得 4.9mm间隙 ,经过三年追踪与对照组相比 ,有显著性差异。结论 替牙早期治疗功能性安氏Ⅲ类错牙合可为尖牙及双尖牙萌出提供间隙。

ObjectiveTo investigate the influence of early Vs late treatment of pseudo Class Ⅲ malocclusion on the length of arches.MethodsTwenty-five consecutive patients with mean age of 9.8 years were included in the early treated group with pseudo Class Ⅲ malocclusion.Fifteen untreated subjects were used as matched controls Eighteen Subjects with three years follow-up after completion of treatment were included in the follow-up group.Lateral cephalograms and study models were analyzed for the treated, the control and the follow-up groups.The arithmetic mean and standard deviation (SD) were calculated for each variable and paired t-tests were performed to assess the effects of treatment on the treated group.The Mann-Whitney test was performed to evaluate the difference between the follow-up group and the control group.ResultsOn average, space gained from the treatment was 4.9 mm in the upper arch.Comparison of the space created as a result of early treatment to the space required for alignment of posterior segments in the upper arch of the untreated control group indicated that there was enough space for the eruption of the canines and premolars as a result of early treatment.ConclusionEarly treatment of Pseudo Class III malocclusion could provide enough space for the eruption of the canines and premolars.