Booth Frederick A, Edelman Justin M, Proffit William R
Department of Orthodontics, School of Dentistry, University of North Carolina, Chapel Hill, NC, USA.
Am J Orthod Dentofacial Orthop. 2008 Jan;133(1):70-6. doi: 10.1016/j.ajodo.2006.10.023.
Many orthodontists believe permanent retention is the only way to maintain ideal tooth alignment after treatment. Fixed bonded retainers are now routinely left in place for many years, even decades. The purpose of this study was to examine the health effects and effectiveness of very long-term retention.
Sixty patients who had had bonded canine-to-canine retainers placed a minimum of 20 years previously were recalled.
Forty-five still had the retainers still in place, and, of these, only 1 had an irregularity index score >2 mm. In this group, the retainers of 28 patients had never broken, and the retainers were repaired once for 8 patients and more than once for 9. The other 15 patients had had their retainers removed outside the orthodontic practice 5 to 25 years previously. In 13 of these patients, the irregularity index score was >3 mm, and 5 of them had scores >4 mm. Gingival index scores for all teeth from first molar to first molar in both arches demonstrated no detrimental effects to the mandibular anterior gingiva from leaving these retainers in place, and the mean score for the maxillary incisor area was better in the patients with a retained mandibular retainer, suggesting better hygiene in the group with retainers.
Long-term retention of mandibular incisor alignment is acceptable to most patients and quite compatible with periodontal health.
许多正畸医生认为，永久性保持是治疗后维持理想牙齿排列的唯一方法。如今，固定粘结保持器通常会保留数年甚至数十年。本研究的目的是探讨长期保持的健康影响和有效性。
召回60例至少在20年前放置了犬齿间粘结保持器的患者。
45例患者的保持器仍在位，其中只有1例的不规则指数评分>2 mm。在这组患者中，28例患者的保持器从未折断，8例患者的保持器修复过1次，9例患者的保持器修复过不止1次。另外15例患者在正畸治疗结束后5至25年将保持器取出。其中13例患者的不规则指数评分>3 mm，5例患者的评分>4 mm。两个牙弓中从第一磨牙到第一磨牙的所有牙齿的牙龈指数评分显示，保留这些保持器对下颌前牙龈没有有害影响，并且在下颌保持器保留的患者中，上颌切牙区域的平均评分更好，表明保留保持器的组口腔卫生更好。
大多数患者可以接受下颌切牙排列的长期保持，并且与牙周健康相当兼容。
