Ormiston Jonathan Perry, Huang Greg J, Little Robert M, Decker Jay D, Seuk Geoffrey D
Department of Orthodontics, University of Washington, Seattle 98195-7446, USA.
Am J Orthod Dentofacial Orthop. 2005 Nov;128(5):568-74; quiz 669. doi: 10.1016/j.ajodo.2004.07.047.
The purpose of this study was to compare groups of patients with the most stable and the most unstable treatment results as rated by the peer assessment rating (PAR) index to identify factors associated with stability. All factors with significant crude odds ratios were investigated to create a multiple logistic regression model that could be used to predict stability.
The sample of 86 patients (30 male, 56 female), from the post-retention archives at the University of Washington, was not restricted to specific malocclusion types or treatment modalities with the exception of Angle Class III patients, who were excluded. The sample was divided into 2 groups, stable (n = 45) and unstable (n = 41), based on post-retention unweighted PAR scores and PAR score changes between posttreatment and post-retention. Model and radiographic measurements were made before treatment, after treatment, and after retention (average 14.4 years).
The results showed that male sex and a sustained period of growth were related, and both were associated with increased instability. The initial severity of malocclusion, as graded by the PAR index and the irregularity index, was negatively correlated with post-retention stability-ie, patients with more severe index scores before treatment tended to be less stable. Differences in American Board of Orthodontics scores after treatment were diminished after retention.
The factors associated with predicting stability were pretreatment arch length, pretreatment PAR score, molar classification, and sex.
本研究的目的是比较根据同行评估评级（PAR）指数评定的治疗结果最稳定和最不稳定的患者组，以确定与稳定性相关的因素。对所有具有显著粗比值比的因素进行研究，以建立一个可用于预测稳定性的多元逻辑回归模型。
从华盛顿大学的保留后档案中选取86例患者（30例男性，56例女性）作为样本，除安氏III类患者被排除外，样本不受特定错牙合类型或治疗方式的限制。根据保留后未加权的PAR评分以及治疗后与保留后的PAR评分变化，将样本分为两组，稳定组（n = 45）和不稳定组（n = 41）。在治疗前、治疗后和保留后（平均14.4年）进行模型和影像学测量。
结果显示，男性性别与持续生长阶段相关，且两者均与不稳定增加有关。由PAR指数和不规则指数分级的错牙合初始严重程度与保留后稳定性呈负相关，即治疗前指数评分越高的患者往往越不稳定。治疗后美国正畸委员会评分的差异在保留后减小。
与预测稳定性相关的因素有治疗前牙弓长度、治疗前PAR评分、磨牙分类和性别。
