Francisconi Manoela Fávaro, Janson Guilherme, Freitas Karina Maria Salvatore, Oliveira Renata Cristina Gobbi de, Oliveira Ricardo César Gobbi de, Freitas Marcos Roberto de, Henriques José Fernando Castanha
Graduate student, Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil.
Professor, Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil.
Am J Orthod Dentofacial Orthop. 2014 Jul;146(1):67-72. doi: 10.1016/j.ajodo.2014.04.012.
In this study, we aimed to compare the relapse of maxillary and mandibular anterior crowding, overjet, and overbite 5 years after treatment in subjects with Class I and Class II malocclusions treated with and without extractions, and also to evaluate the correlations among these factors.
The sample comprised 84 subjects with Class I and Class II malocclusions, treated with and without extractions. Group 1 comprised 44 subjects with an initial mean age of 12.96 years treated without extractions. Group 2 included 40 subjects with an initial mean age of 13.01 years treated with 4 premolar extractions. Data were obtained from dental casts at the pretreatment, posttreatment, and long-term posttreatment stages. Intergroup comparisons were performed with t tests. To verify the correlations among the relapse of overjet, overbite, and anterior crowding, the Pearson correlation test was used.
Maxillary incisor irregularity and its relapse in the nonextraction group were significantly greater at the long-term posttreatment stage and the long-term posttreatment period, respectively. Long-term postreatment overjet changes were similar in the groups. Overbite and its relapse were significantly greater in the extraction group in the long-term posttreatment stage and period, respectively. There was a positive correlation of the relapse of mandibular incisor crowding with the relapse of overjet and overbite, and also a correlation of overjet and overbite relapses.
There was greater maxillary crowding relapse in the nonextraction group and greater overbite relapse in the extraction group. There were significant and positive correlations of overjet and overbite relapses with mandibular anterior crowding relapse and consequently between overjet and overbite relapses.
在本研究中，我们旨在比较接受和未接受拔牙治疗的Ⅰ类和Ⅱ类错牙合畸形患者治疗5年后上颌和下颌前牙拥挤、覆盖和覆牙合的复发情况，并评估这些因素之间的相关性。
样本包括84例Ⅰ类和Ⅱ类错牙合畸形患者，接受了拔牙和未拔牙治疗。第1组包括44例初始平均年龄为12.96岁且未接受拔牙治疗的患者。第2组包括40例初始平均年龄为13.01岁且拔除4颗前磨牙的患者。数据来自治疗前、治疗后和长期治疗后阶段的石膏模型。采用t检验进行组间比较。为验证覆盖、覆牙合和前牙拥挤复发之间的相关性，使用Pearson相关检验。
在长期治疗后阶段和长期治疗后期间，不拔牙组的上颌切牙不齐及其复发分别显著更大。两组长期治疗后的覆盖变化相似。在长期治疗后阶段和期间，拔牙组的覆牙合及其复发分别显著更大。下颌切牙拥挤的复发与覆盖和覆牙合的复发呈正相关，覆盖和覆牙合的复发之间也存在相关性。
不拔牙组上颌拥挤复发更大，拔牙组覆牙合复发更大。覆盖和覆牙合的复发与下颌前牙拥挤复发之间存在显著正相关，因此覆盖和覆牙合的复发之间也存在显著正相关。
