Gebeile-Chauty Sarah, Akharzouz Caroline, Schott Anne-Marie, Gelas-Dore Bénédicte, Aknin Jean-Jacques
Département d'Orthopédie Dento-Faciale, Guillaume-Paradin, Lyon, France.
Orthod Fr. 2009 Dec;80(4):401-13. doi: 10.1051/orthodfr/2009030. Epub 2009 Dec 4.
Indication of intermediate retention after early treatment of class II malocclusion has not been yet assessed by comparative studies. Therefore, it is up to the practitioner to analyse the need for retention in the time period between the two phases. Does wearing a retainer indeed decrease the chance of relapse between phase one and phase two? We performed a retrospective comparative study consisting of 90 subjects in mixed dentition with class II molar relationships with an increased overjet (> or = 5 mm) treated in the J.-J. Aknin office with DAC appliance. The sample was divided into two groups: 31 patients wearing retention represented by a removable Hawley plate and 59 children in supervision without retention. Three lateral head-films were made at the beginning and the end of early treatment and before the resumption of the second phase treatment. Studied cephalometrics parameters were assessed according to superimposing Pancherz's analysis. A statistical analysis was performed. Results showed a significantly lower relapse of incisor's protrusion in the group wearing an upper retainer. Results' interpretation was in accordance with the assessment of confusion's factors and selection's criteria. Besides, this study was carried out in intention-to-treat and retention's effectiveness in proportion with patient's compliance. Nevertheless, the study was performed in real conditions. In conclusion, and without randomised trial, results show that retention seems to decrease maxillary incisor movements. It is therefore justified in cases presenting with important class II especially with procumbent incisors.
关于II类错牙合早期治疗后中期保持的指征尚未通过比较研究进行评估。因此，需要从业者分析两个阶段之间的保持需求。佩戴保持器是否真的能降低第一阶段和第二阶段之间复发的几率？我们进行了一项回顾性比较研究，研究对象为90名处于混合牙列期、II类磨牙关系且覆盖增加（≥5毫米）的患者，他们在J.-J. 阿金诊所接受了DAC矫治器治疗。样本分为两组：31名佩戴可摘式霍利保持器的患者作为保持组，59名未佩戴保持器处于观察期的儿童作为观察组。在早期治疗开始和结束时以及第二阶段治疗恢复前拍摄了三张头颅侧位片。根据潘彻兹叠加分析法评估所研究的头影测量参数，并进行了统计分析。结果显示，佩戴上颌保持器的组中切牙前突的复发率显著降低。结果的解释符合干扰因素评估和选择标准。此外，本研究采用意向性分析，且保持效果与患者依从性成正比。尽管如此，该研究是在实际情况下进行的。总之，在没有随机试验的情况下，结果表明保持似乎能减少上颌切牙的移动。因此，在存在严重II类错牙合尤其是切牙前倾的病例中，保持是合理的。
