Systematic review of mini-implant displacement under orthodontic loading

作     者：Manuel Nienkemper Jrg Handschel Dieter Drescher 

作者机构：Department of Orthodontics Heinrich-Heine-University Department of Oral and Maxillofacial Surgery Heinrich-Heine-University 

出 版 物：《International Journal of Oral Science》 (国际口腔科学杂志（英文版）)

年 卷 期：2014年第6卷第1期

页      面：1-6页

核心收录：

学科分类：1003[医学-口腔医学] 100302[医学-口腔临床医学] 10[医学] 

主　　题：displacement migration mini-implant miniscrew orthodontics skeletal anchorage 

摘      要：A growing number of studies have reported that mini-implants do not remain in exactly the same position during treatment, although they remain stable. The aim of this review was to collect data regarding primary displacement immediately straight after loading and secondary displacement over time. A systematic review was performed to investigate primary and secondary displacement. The amount and type of displacement were recorded. A total of 27 studies were included. Sixteen in vitro studies or studies using finite element analysis addressed primary displacement, and nine clinical studies and two animal studies addressed secondary displacement. Significant primary displacement was detected （6.4-24.4 μm） for relevant orthodontic forces （0.5-2.5 N）. The mean secondary displacement ranged from 0 to 2.7 mm for entire mini-implants, The maximum values for each clinical study ranged from 1.0 to 4.1 mm for the head, 1.0 to 1.5 for the body and 1,0 to 1.92 mm for the tail part. The most frequent type of movement was controlled tipping or bodily movement. Primary displacement did not reach a clinically significant level. However, clinicians can expect relevant secondary displacement in the direction of force. Consequently, decentralized insertion within the inter-radicular space, away from force direction, might be favourable. More evidence is needed to provide quantitative recommendations.