Freitas Marcos Roberto de, Castro Renata Cristina Faria Ribeiro de, Janson Guilherme, Freitas Karina Maria Salvatore, Henriques José Fernando Castanha
Department of Orthodontics, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil.
Am J Orthod Dentofacial Orthop. 2006 Apr;129(4):559-61. doi: 10.1016/j.ajodo.2005.10.019.
Considering postretention stability as a result of successful orthodontic treatment, we aimed to verify the influence of mandibular-incisor-crown morphology in the relapse of mandibular anterior crowding.
The sample comprised 56 white subjects of both sexes with Class I and Class II malocclusions at pretreatment, treated with extraction of 4 first premolars and edgewise mechanics. No patient underwent interproximal stripping during or after treatment. Mean pretreatment age was 13.23 years. Mean treatment time was 2.11 years, and mean posttreatment evaluation time was 5.12 years. Mandibular anterior crowding was measured with the Little irregularity index, and the mesiodistal and buccolingual proportion of the mandibular incisor crowns was measured with the Peck and Peck index. The measurements were obtained from dental casts at the pretreatment, posttreatment, and postretention stages. The Pearson correlation coefficient was calculated to determine the correlation between mandibular-incisor-crown morphology and the amount of postretention-crowding relapse.
The mandibular-incisor-crown morphologic index was not significantly correlated with the amount of mandibular-anterior-crowding relapse.
Mandibular-incisor-crown morphology is not correlated with the amount of mandibular-anterior-crowding relapse.
鉴于成功的正畸治疗会带来矫治后稳定性，我们旨在验证下颌切牙冠形态对下颌前牙拥挤复发的影响。
样本包括56名白种人受试者，性别不限，治疗前均为安氏I类和II类错牙合畸形，采用拔除4颗第一前磨牙及方丝弓矫治技术进行治疗。治疗期间及治疗后无患者接受邻面去釉。治疗前平均年龄为13.23岁。平均治疗时间为2.11年，平均治疗后评估时间为5.12年。采用Little不规则指数测量下颌前牙拥挤程度，采用Peck和Peck指数测量下颌切牙冠的近远中及颊舌向比例。这些测量数据来自治疗前、治疗后及矫治后阶段的石膏模型。计算Pearson相关系数以确定下颌切牙冠形态与矫治后拥挤复发量之间的相关性。
下颌切牙冠形态指数与下颌前牙拥挤复发量无显著相关性。
下颌切牙冠形态与下颌前牙拥挤复发量无关。
