Schaefer Abbie T, McNamara James A, Franchi Lorenzo, Baccetti Tiziano
Graduate Orthodontic Program, University of Michigan, Ann Arbor, MI 48109, USA.
Am J Orthod Dentofacial Orthop. 2004 Jul;126(1):7-15. doi: 10.1016/j.ajodo.2003.06.017.
This study compared the effects of 2 treatment protocols for correcting Class II disharmony. The first phase of treatment consisted of functional jaw orthopedics with either the Twin-block or the stainless-steel crown Herbst appliance; the second phase consisted of comprehensive fixed-appliance therapy in both protocols. Each of the 2 samples comprised 28 consecutively treated Class II patients. The mean age at the start of treatment was approximately 12 years, and the mean age at the end of the treatment was approximately 14.5 years in both groups. The duration of the treatment phase with the functional appliance was approximately 13 months, and the duration of fixed-appliance therapy was approximately 15 months in both groups. The sex distribution was identical in the 2 groups. Lateral cephalograms were analyzed at the start of treatment (T1) and at the end of the overall treatment protocol (T2). Nonparametric statistics were used for comparisons of starting forms and of the T1-T2 changes between the 2 treatment groups. The stainless-steel crown Herbst appliance and the Twin-block appliance produced very similar therapeutic modifications in Class II patients, although the Twin-block group exhibited almost 2 mm greater correction of the maxillomandibular differential than did the crown Herbst group. The treatment effects of both protocols led to a normalization of the dentoskeletal parameters at the end of the overall treatment period. Twin-block therapy also induced a greater increase in the height of the mandibular ramus (posterior facial height). Overall, only minor differences were detected in the treatment and posttreatment effects of a compliance-free (crown Herbst) and a noncompliance-free (Twin-block) appliance for correcting Class II disharmony.
本研究比较了两种治疗方案对纠正安氏II类错牙合的效果。治疗的第一阶段包括使用Twin-block矫治器或不锈钢冠Herbst矫治器进行功能性颌骨矫形；两个方案的第二阶段均包括全面的固定矫治器治疗。两个样本各包含28例连续接受治疗的安氏II类患者。两组治疗开始时的平均年龄约为12岁，治疗结束时的平均年龄约为14.5岁。两组使用功能性矫治器的治疗阶段时长约为13个月，固定矫治器治疗的时长约为15个月。两组的性别分布相同。在治疗开始时（T1）和整个治疗方案结束时（T2）分析头颅侧位片。使用非参数统计方法比较两个治疗组的初始形态以及T1至T2的变化。不锈钢冠Herbst矫治器和Twin-block矫治器在安氏II类患者中产生了非常相似的治疗性改变，尽管Twin-block组的上下颌差异矫正量比冠Herbst组大近2mm。两种方案的治疗效果均使整个治疗期结束时的牙颌面参数恢复正常。Twin-block治疗还使下颌升支高度（面部后份高度）有更大增加。总体而言，在用于纠正安氏II类错牙合的无需患者配合的（冠Herbst）矫治器和需要患者配合的（Twin-block）矫治器的治疗及治疗后效果方面，仅检测到微小差异。
