Department of Dentistry, Section of Periodontology, Aarhus University, Aarhus, Denmark; Department of Orthodontics and Dentofacial Orthopedics, School of Dental Medicine, University of Bern, Bern, Switzerland.
Orthod Craniofac Res. 2013 Nov;16(4):223-33. doi: 10.1111/ocr.12025. Epub 2013 Jun 24.
To present the development of an experimental model in rats for translational expansive tooth movement.
Section of Periodontology at Department of Dentistry Aarhus University. Twenty male Wistar rats in two pilot experimental settings plus seven animals without any intervention serving as controls.
The second molar (group P1) or the second and third molar (group P2) in the maxillae of the animals were moved buccally using transpalatal β-titanium springs. In the group P2, two spring types (high force and low force) and two preangulations (0° passive or 30° torsion moment) were tested. The amount and type of tooth movement achieved and the resulting skeletal effect were assessed on microCT images, histological analysis was performed on few selected specimens.
Expansive translational root movement amounting half a tooth width was achieved. Comparison of the amount of tooth movement at the right and left side of the maxilla showed that the expansion was rather symmetrical in the P2 group. Skeletal widening of the maxilla contributed in the P2 group to approximately one-third of the total root movement, whereas two-thirds were dental movement.
With the model used in the P2 group, further research on translational expansive tooth movement and its effect on the periodontium can be pursued. In models for orthodontic expansion, it is strongly recommended to separately evaluate skeletal and dental effects.
介绍一种用于大鼠牙齿平移扩张实验模型的发展。
丹麦奥胡斯大学牙科学系牙周病科。20 只雄性 Wistar 大鼠，分为两个实验设置的实验组，加上 7 只未进行任何干预的对照组动物。
使用跨腭β钛弹簧将上颌的第二磨牙（P1 组）或第二和第三磨牙（P2 组）颊向移动。在 P2 组中，测试了两种弹簧类型（高力和低力）和两种预倾斜（0°被动或 30°扭转力矩）。使用 microCT 图像评估获得的牙齿移动量和类型以及由此产生的骨骼效应，对少数选定的标本进行了组织学分析。
实现了半颗牙齿宽度的扩张性平移根移动。对上颌骨右侧和左侧牙齿移动量的比较表明，P2 组的扩张相当对称。上颌骨的骨宽增加在 P2 组中约占总根移动的三分之一，而三分之二是牙齿移动。
使用 P2 组中的模型，可以进一步研究平移扩张牙齿移动及其对牙周组织的影响。在正畸扩张模型中，强烈建议分别评估骨骼和牙齿的效果。
