Ren Yijin, Maltha Jaap C, Kuijpers-Jagtman Anne Marie
Department of Orthodontics and Oral Biology, College of Dental Science, University Medical Centre Nijmegen, The Netherlands.
Eur J Orthod. 2004 Oct;26(5):483-90. doi: 10.1093/ejo/26.5.483.
The aims of this study were to perform a systematic review of the use of rats as a model for experimental tooth movement, to give a critical evaluation of the use of elastics as a force delivery system, and to describe a newly designed well-defined model for tooth movement in rats. The literature from 1981 to 2002 indicates that in 57 per cent of animal studies on orthodontic tooth movement, rats were used, but in many of these investigations the experimental set-up was poorly documented. Only three of the 159 studies fulfilled the inclusion criteria for a good model: a force magnitude of less than 20 cN; moving molar(s) mesially; an experimental duration longer than 2 weeks; and no extra experimental condition such as drug intervention. As more than one-quarter of the studies on tooth movement in rats used elastics to produce an orthodontic force, and as the forces they produced and their force decay during decompression are unknown, their mechanical characteristics on decompression were tested. Elastics stored under dry conditions or in water showed significant force decay from around 45 N to almost 0 N within the first 0.2 mm of decompression. With regard to the above-mentioned shortcomings of using rats as a model for tooth movement, a newly designed experimental appliance for tooth movement in rats was evaluated. It proved to be stable and simple and able to deliver a continuous and constant force as low as 10 cN on all three molars together during an experimental period of 12 weeks without interference in animal welfare, and was able to compensate for the effects of molar distal drift and continuous incisor eruption.
本研究的目的是对将大鼠用作实验性牙齿移动模型的情况进行系统综述，对使用弹力线作为力传递系统进行批判性评估，并描述一种新设计的、定义明确的大鼠牙齿移动模型。1981年至2002年的文献表明，在57%的正畸牙齿移动动物研究中使用了大鼠，但在许多这些研究中，实验设置记录不佳。159项研究中只有3项符合良好模型的纳入标准：力大小小于20厘牛顿；使磨牙近中移动；实验持续时间超过2周；且无药物干预等额外实验条件。由于超过四分之一的大鼠牙齿移动研究使用弹力线产生正畸力，且它们产生的力及其在解压过程中的力衰减未知，因此测试了它们在解压时的力学特性。在干燥条件下或水中储存的弹力线在解压的前0.2毫米内显示出显著的力衰减，从约45牛顿降至几乎0牛顿。针对将大鼠用作牙齿移动模型的上述缺点，对一种新设计的大鼠牙齿移动实验装置进行了评估。结果证明它稳定且简单，在12周的实验期内能够在不干扰动物福利的情况下，对所有三颗磨牙一起施加低至10厘牛顿的连续恒定力，并且能够补偿磨牙远中漂移和切牙持续萌出的影响。
