Männchen Roland, Serafin Marco, Fastuca Rosamaria, Caprioglio Alberto
Independent Researcher, 8400 Winterthur, Switzerland.
Department of Biomedical Sciences for Health, University of Milan, 20133 Milan, Italy.
Children (Basel). 2022 Feb 9;9(2):232. doi: 10.3390/children9020232.
The present study was carried out to evaluate the benefits from one-phase Class II Early Treatment (ET) using extraoral forces and functional appliances but without intermaxillary forces and eventual lower leeway space preservation compared to two-phase Class II Late Treatment (LT) with the need for extractions and full fixed appliances as well as lower incisor proclination. The ET group ( = 239, 115 M, 124 F, mean age 10.6 ± 1.2 years), with first premolars not in contact and the second deciduous lower molars preserved, was compared to the LT group ( = 288, 137 M, 151 F, mean age 12.4 ± 1.5 years). The ET group was first treated with headgears, growth guide appliances, or Teuscher activators and, in borderline crowding cases, with lower space maintenance by a lingual arch, lip bumper, or fixed utility arch. The LT group and the second phase of ET were treated with full fixed appliances including intermaxillary forces such as Class II elastics or noncompliance devices; headgear and a growth guide appliance were also used. Cephalograms and plaster models were taken before (T1) and after treatment (T2) to calculate cephalometric changes and space balance discrepancies. The differences between T1 and T2 were analyzed by a -test for normally distributed data and by the Mann-Whitney Test for nonnormally distributed data at a level of < 0.05. The groups were defined as statistically homogeneous at T1. A statistical analysis showed that the ET group (mean treatment time 35.3 ± 13.3 months) was significantly associated with a 22.2% lower extraction rate, 15.9% less need for a full fixed appliance, and more than 5° less incisor proclination in the nonextraction cases compared to the LT group (mean treatment time 25.9 ± 8.1 months); treatment time significantly increased in the ET group compared to the LT group. Early Class II treatment resulted in a significant treatment effort reduction in more than one third of the patients and less lower incisor proclination, even if it clinically increased treatment time.
本研究旨在评估与二期安氏II类错颌晚期治疗（LT）相比，一期安氏II类错颌早期治疗（ET）使用口外矫治力和功能矫治器，但不使用颌间牵引力且最终保留下颌剩余间隙的益处。二期安氏II类错颌晚期治疗需要拔牙、使用全固定矫治器以及压低下切牙。将ET组（n = 239，男115例，女124例，平均年龄10.6±1.2岁）与LT组（n = 288，男137例，女151例，平均年龄12.4±1.5岁）进行比较，ET组第一前磨牙未接触且保留第二乳磨牙。ET组首先使用头帽、生长引导矫治器或Teuscher矫治器进行治疗，在临界拥挤病例中，使用舌弓、唇挡或固定功能弓维持下颌间隙。LT组和ET组的第二阶段使用全固定矫治器进行治疗，包括使用II类牵引或非依从性装置等颌间牵引力；也使用头帽和生长引导矫治器。在治疗前（T1）和治疗后（T2）拍摄头影测量片和石膏模型，以计算头影测量变化和间隙平衡差异。对于正态分布数据，通过t检验分析T1和T2之间的差异；对于非正态分布数据，通过Mann-Whitney检验进行分析，检验水准α<0.05。两组在T1时定义为统计学上同质。统计分析表明，与LT组（平均治疗时间25.9±8.1个月）相比，ET组（平均治疗时间35.3±13.3个月）拔牙率显著降低22.2%，使用全固定矫治器的需求减少15.9%，在不拔牙病例中下切牙倾斜度减少超过5°；与LT组相比，ET组治疗时间显著延长。早期安氏II类错颌治疗使超过三分之一的患者治疗工作量显著减少，下切牙倾斜度减小，即使临床上治疗时间延长。
