骨性Ⅲ类错[牙合]畸形不同拔牙模式矫治的PAR指数评价

Peer assessment rating index analysis of different extraction modality in skeletal Class Ⅲ malocclusions

目的 评价不同拔牙模式对骨性Ⅲ类错[牙合]畸形治疗效果的影响.方法 选择109例骨性Ⅲ类错[牙合]畸形患者,其中男性50例,女性59例,平均年龄16.11岁±4.47岁.根据拔牙模式分为：T0组（不拔牙）、T1组（拔前磨牙）、T2组（拔磨牙）和T3组（拔下切牙）.对所有患者治疗前后的模型应用PAR（Peer Assessment Rating）指数进行评价,对各组治疗前后的加权PAR总分值、加权PAR总分值减少、加权PAR分值减少率及改善程度进行统计学分析.结果 ①治疗后加权PAR总分值减少和加权PAR总分值减少率在各组间有显著的统计学差异（P＜0.001）,减少从多到少的顺序依次是拔前磨牙组、拔磨牙组、不拔牙组和拔下切牙组;②四种不同拔牙模式组中均无变坏或无改变,极大改善97例,占总例数的89%,改善12例,占总例数的11%;③不同拔牙模式组之间的矫治等级结果有统计学差异（P＜0.05）,拔前磨牙组中极大改善所占比例最大,而拔下切牙组中极大改善比例最小.结论 四种不同拔牙模式都能起到改善骨性Ⅲ类错[牙合]畸形牙[牙合]关系的目的 ,但拔下切牙的模式应慎重选择.

Objective To assess the effect of different extraction modalities on treatment outcomes in skeletal Class Ⅲ malocclusions. Methods One hundred and nine skeletal Class Ⅲ patients （50 males and 59 females） with a mean age of 16.11±4.47 years were collected. The subjects were divided into four groups according to the extraction modality. They were T0 （non-extraction group）, T1 （premolar extraction group）, T2 （molar extraction group） and T3 （lower incisor extraction group）. The PAR （peer assessment rating） index of each of the pre- and post-treatment cast was assessed. The differences of pre- and post-treatment weighed PAR score, reduction in weighed PAR score, percentage reduction in weighed PAR score and the degree of improvement between the four groups were compared. Results （1） Significant differences （P〈0.001= of the reduction in weighed PAR score and percentage reduction in weighed PAR score existed between different extraction modality groups. And the order of reduction from high to low was premolar extraction group, molar extraction group, non-extraction group and lower incisor extraction group.（2） There were no ＂Worse-no different＂ cases among the four groups. 97 cases were greatly improved and accounted for 89%. There were 12 cases （11%） in improved category. （3） Greatest improvement was found in premolar extraction group and the least improvement was found in lower incisor extraction group. Conclusions Treatment outcomes of the four extraction modalities in skeletal Class Ⅲ were all satisfied. Cautions should be paid in lower incisor extraction.