Westerlund Anna, Oikonomou Charitini, Ransjö Maria, Ekestubbe Annika, Bresin Andrea, Lund Henrik
Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
Specialist Clinic of Orthodontics, Public Dental Service, Västra Götaland Region, Gothenburg, Sweden.
Am J Orthod Dentofacial Orthop. 2017 Jan;151(1):74-81. doi: 10.1016/j.ajodo.2016.06.029.
Fixed retainers are widely used after orthodontic treatment, sometimes for extended periods, despite insufficient knowledge of their possible long-term adverse effects on the periodontium. The aim of this study was to evaluate whether bonded orthodontic retainers have an adverse long-term effect on the marginal bone levels of the mandibular front teeth.
The study included 62 consecutive patients in 3 groups: (1) patients who underwent orthodontic treatment and wore a fixed retainer for 10 years, (2) patients who underwent orthodontic treatment but did not have a fixed retainer, and (3) untreated controls. The marginal bone levels were measured by cone-beam computed tomography 10 years after treatment. Additionally, multivariate data analysis was used to analyze possible correlations between the marginal bone levels at 10 years and the variables obtained from the study casts and profile radiographs.
The results demonstrated a significantly lower marginal bone level on the buccal side of the mandibular front teeth in the orthodontically treated patients compared with the orthodontically untreated group. There was no difference in the marginal bone levels between the retainer group and the no-retainer group. Multivariate analysis indicated that a low marginal bone level was correlated with a basal open vertical relationship, posterior rotation of the mandible, pretreatment of the incisor protrusion, and extraction therapy.
Within the limits of this research design, the long-term retention phase in general does not seem to cause any adverse effects on the marginal bone levels after 10 years.
尽管对正畸固定保持器对牙周组织可能产生的长期不良影响了解不足，但正畸治疗后仍广泛使用固定保持器，有时使用时间还很长。本研究的目的是评估正畸粘结固定保持器是否会对下颌前牙的边缘骨水平产生长期不良影响。
该研究纳入了连续62例患者，分为3组：（1）接受正畸治疗并佩戴固定保持器10年的患者；（2）接受正畸治疗但未佩戴固定保持器的患者；（3）未接受治疗的对照组。治疗10年后，通过锥形束计算机断层扫描测量边缘骨水平。此外，使用多变量数据分析10年后边缘骨水平与从研究模型和侧面X线片获得的变量之间的可能相关性。
结果表明，与未接受正畸治疗的组相比，接受正畸治疗的患者下颌前牙颊侧的边缘骨水平明显更低。保持器组和无保持器组之间的边缘骨水平没有差异。多变量分析表明，边缘骨水平低与基底开放垂直关系、下颌后旋、切牙前突的预处理和拔牙治疗有关。
在本研究设计的范围内，一般来说，长期保持阶段在10年后似乎不会对边缘骨水平造成任何不良影响。
