Pavlow Sarah S, McGorray Susan P, Taylor Marie G, Dolce Calogero, King Gregory J, Wheeler Timothy T
Am J Orthod Dentofacial Orthop. 2008 Feb;133(2):235-44. doi: 10.1016/j.ajodo.2006.02.038.
The purpose of this study was to evaluate the effect of early treatment on the stability of occlusion in patients with Class II malocclusions. The peer assessment rating (PAR) index was used to evaluate changes in occlusion after treatment of subjects treated in 1 phase or 2 phases. This study was a prospective, randomized, controlled clinical trial.
Dental casts were obtained from the participants, who were randomized into 3 phase-1 early treatment groups: bionator, headgear/bite plane, or observation. Phase 2 consisted of continued treatment of the bionator and the headgear/biteplane subjects and comprehensive treatment of the observation subjects. PAR scores were obtained for 208 subjects at end of treatment; 173 (83%) had at least 1 follow-up visit, with a median follow-up time of 5.0 years. PAR scores were calculated for each subject at key treatment and posttreatment time points. Linear mixed-effect models were used to evaluate the impact of phase-1 treatment group, years posttreatment, end of treatment PAR score, and other covariates that could affect stability on the posttreatment PAR score.
Factors significantly affecting posttreatment PAR scores were PAR score at end of treatment (P <.0001), years posttreatment (P =.0064), and PAR score at the start of phase 2. Although phase-1 treatment was not statistically significant, those with early treatment had lower PAR scores at the start of phase 2 than the observation subjects (means [SD]: bionator 17.5 [7.4], headgear/biteplane 15.3 [7.0], observation 22.2 [8.6], P <.0001). Thus, early treatment had an indirect effect.
Factors that affect posttreatment PAR score stability include PAR score at the end of treatment, years posttreatment, and PAR score at the start of phase-2 treatment. The early treatment modalities have limited positive impact on posttreatment stability PAR scores in Class II malocclusion patients due to their effect on PAR scores at the start of phase-2 treatment.
本研究的目的是评估早期治疗对安氏II类错牙合患者咬合稳定性的影响。采用同伴评估评分（PAR）指数来评估接受1期或2期治疗的受试者治疗后咬合的变化。本研究是一项前瞻性、随机、对照临床试验。
从参与者处获取牙模，将其随机分为3个1期早期治疗组：生物调节器组、头帽/平面导板组或观察组。2期包括生物调节器组和头帽/平面导板组受试者的继续治疗以及观察组受试者的综合治疗。在治疗结束时为208名受试者获取PAR评分；173名（83%）受试者至少有1次随访，中位随访时间为5.0年。在关键治疗和治疗后时间点为每个受试者计算PAR评分。采用线性混合效应模型评估1期治疗组、治疗后年份、治疗结束时的PAR评分以及其他可能影响治疗后PAR评分稳定性的协变量的影响。
显著影响治疗后PAR评分的因素为治疗结束时的PAR评分（P<.0001）、治疗后年份（P=.0064）以及2期开始时的PAR评分。虽然1期治疗在统计学上无显著差异，但早期治疗的受试者在2期开始时的PAR评分低于观察组受试者（均值[标准差]：生物调节器组17.5[7.4]，头帽/平面导板组15.3[7.0]，观察组22.2[8.6]，P<.0001）。因此，早期治疗有间接影响。
影响治疗后PAR评分稳定性的因素包括治疗结束时的PAR评分、治疗后年份以及2期治疗开始时的PAR评分。由于早期治疗方式对2期治疗开始时PAR评分的影响，其对安氏II类错牙合患者治疗后稳定性PAR评分的积极影响有限。
