Shaughnessy Timothy G, Proffit William R, Samara Said A
Private practice, Marietta and Suwanee, Ga, and Abu Dhabi, United Arab Emirates.
Emeritus professor, Department of Orthodontics, School of Dentistry, University of North Carolina, Chapel Hill, NC.
Am J Orthod Dentofacial Orthop. 2016 Feb;149(2):277-86. doi: 10.1016/j.ajodo.2015.10.015.
Fixed retainers are effective in maintaining the alignment of the anterior teeth more than 90% of the time, but they can produce inadvertent tooth movement that in the most severe instances requires orthodontic retreatment managed with a periodontist. This is different from relapse into crowding when a fixed retainer is lost. These problems arise when the retainer breaks but remains bonded to some or all teeth, or when an intact retainer is distorted by function or was not passive when bonded. In both instances, torque of the affected teeth is the predominant outcome. A fixed retainer made with dead soft wire is the least likely to create torque problems but is the most likely to break. Highly flexible twist wires bonded to all the teeth appear to be the most likely to produce inadvertent tooth movement, but this also can occur with stiffer wires bonded only to the canines. Orthodontists, general dentists, and patients should be aware of possible problems with fixed retainers, especially those with all teeth bonded, because the patient might not notice partial debonding. Regular observations of patients wearing fixed retainers by orthodontists in the short term and family dentists in the long term are needed.
固定保持器在超过90%的时间里能有效维持前牙排列整齐，但它们可能会导致意外的牙齿移动，在最严重的情况下需要正畸医生与牙周病医生共同进行再次治疗。这与固定保持器丢失后复发拥挤不同。当保持器断裂但仍与部分或所有牙齿粘结，或者完整的保持器因功能而变形或粘结时未处于被动状态时，就会出现这些问题。在这两种情况下，受影响牙齿的转矩是主要结果。用极软钢丝制作的固定保持器产生转矩问题的可能性最小，但最容易断裂。粘结到所有牙齿上的高柔韧性麻花丝似乎最容易导致意外的牙齿移动，但仅粘结到尖牙的较硬钢丝也可能出现这种情况。正畸医生、普通牙医和患者都应该意识到固定保持器可能存在的问题，尤其是那些粘结到所有牙齿的保持器，因为患者可能不会注意到部分脱粘。正畸医生需要在短期内定期观察佩戴固定保持器的患者，家庭牙医则需要在长期内进行观察。
