EARLY VS LATE TREATMENT IN CLASS II MALOCCLUSION

目前，大约50%的美国儿童需要正畸 目前有35%-40%的人在许多地区接受治疗。其中， 近一半的人因II类错牙合而接受治疗，这是 以上门牙相对突出为特征的 但最常见的原因是 在生长过程中的下巴。这个项目的目标是比较 骨性II类的三种替代治疗方法 错牙合(即，由于牙合不一致而导致的II类错牙合) 颌骨生长)：早期正畸治疗以改变颌骨生长 青春期前的颌骨；晚期正畸治疗 重新定位牙齿并补偿任何下巴的不一致， 通常在青春期做；以及外科-正畸 重新定位颌骨的治疗(S)，这通常是为 青春期后期或青壮年出现严重问题。 理想情况下，我们将完全在随机临床试验中进行这项研究。 (RCT)，但由于时间限制，不可能只使用 方法在初始授权期内。因此，我们将开始一场 RCT研究早期和晚期正畸治疗，以评估 头戴式头盔的生长修正程度 和/或功能性矫治器治疗，并评估影响 早期治疗对口腔健康的影响。我们还将利用一个 具有回顾和前瞻性数据的观察性研究 两个目的：(1)获得比较这些数据的初步数据 治疗方法和(2)晚期正畸与正畸的比较 正畸--更严重问题的外科治疗。我们的 重点将放在形态治疗效果、数量 达到治疗目标的患者和百分比 改善、对口腔健康的影响和患者的程度 由效用函数表示的满意度。我们会调查的 决策分析技术的潜在用处 确定在给定条件下的最佳治疗方法 条件，并将尝试确定在这种情况下的关键因素 一个决定。质量的显著提高 正畸治疗可以通过以下方式实现： 其中一种治疗方法在特异度上优于 情况。

At present, approximately 50% of U.S. children need orthodontic treatment and 35-40% now receive it in many areas. Of these, nearly half are treated for Class II malocclusion, which is characterized by a relative protrusion of the upper incisor teeth but most frequently is caused by an underdevelopment of the lower jaw during growth. The goal of this project is to compare three alternative treatment approaches to skeletal Class II malocclusion (i.e., Class II malocclusion due to a discrepancy in jaw growth): early orthodontic treatment to modify the growth of the jaws prior to adolescence; late orthodontic treatment to reposition the teeth and compensate for any jaw discrepancy, usually done during adolescence; and surgical-orthodontic treatment to reposition the jaw(s), which typically is reserved for severe problems in late adolescents or young adults. Ideally, we would do this entirely in a randomized clinical trial (RCT), but time constraints make it impossible to use only this method in an initial granting period. Therefore, we will begin a RCT to study early versus late orthodontic treatment, to assess the extent to which growth modification occurs with headgear and/or functional appliance treatment, and to assess the impact of early treatment on oral health. We also will utilize an observational study with retrospective and prospective data for two purposes: (1) to obtain preliminary data comparing these treatment methods and (2) to compare late orthodontic versus orthodontic-surgical treatment of the more severe problems. Our focus will be on the morphologic treatment effects, number of patients in whom treatment goals were reached and percent improvement, impact on oral health, and degree of patient satisfaction as indicated by utility functions. We will investigate the potential usefulness of decision analysis techniques to determine the perferred treatment approach under given conditions and will attempt to identify the critical factors in such a decision. A significant improvement in the quality of orthodontic treatment could be achieved by a demonstration that one of the treatment approaches was superior in specific circumstances.