Kahl-Nieke B, Fischbach H, Schwarze C W
Department of Orthodontics, University of Cologne, Germany.
Br J Orthod. 1995 Aug;22(3):249-57. doi: 10.1179/bjo.22.3.249.
The aim of the present long-term follow-up study of orthodontically-treated patients (mean: 15.7 years) was to analyse post-retention changes and to reveal factors which may play a role as predictors for long-term prognosis. Pretreatment, end-of-treatment, and post-retention models of 226 cases with all types of anomaly were used to measure intercanine and intermolar width, arch length, and sum of the mesiodistal dimension of the incisors, Irregularity Index, crowding, molar and canine relationship, overjet, and overbite. In order to assess the influence of sex, initial and end-of-treatment alignment, type of therapy, amount of tooth movement, and presence of third molars on the extent of post-retention changes, the total sample was divided into subgroups. Findings indicated that post-retention crowding and incisor irregularity increased more frequently in the mandible than in the maxilla. Pretreatment variables such as increased mesiodistal incisor dimension, severe crowding and incisor irregularity, arch length deficiency, arch constriction, and increased overbite as well as post-treatment spacing, arch expansion, increased arch length, and residual Class II or III molar relationships were found to be associated factors in the process of post-retention increase of crowding and incisor irregularity. 'Overexpansion' was found to be a factor in mandibular incisor relapse.
本项针对正畸治疗患者（平均随访15.7年）的长期随访研究旨在分析保持后变化情况，并揭示可能作为长期预后预测指标的因素。使用226例各类牙颌面畸形患者治疗前、治疗结束时和保持后的模型，测量尖牙间宽度、磨牙间宽度、牙弓长度、切牙近远中径总和、不规则指数、牙列拥挤度、磨牙和尖牙关系、覆盖和覆合。为评估性别、初始及治疗结束时的排齐情况、治疗类型、牙齿移动量以及第三磨牙的存在对保持后变化程度的影响，将总样本分为多个亚组。研究结果表明，保持后牙列拥挤和切牙不规则在下颌比上颌更频繁地增加。治疗前变量如切牙近远中径增加、严重牙列拥挤和切牙不规则、牙弓长度不足、牙弓缩窄、覆合增加以及治疗后间隙、牙弓扩展、牙弓长度增加和残留的II类或III类磨牙关系被发现是保持后牙列拥挤和切牙不规则增加过程中的相关因素。“过度扩展”被发现是下颌切牙复发的一个因素。
