Brodin P, Linge L, Aars H
Department of Oral Biology, Faculty of Dentistry, University of Oslo, Norway.
J Orofac Orthop. 1996 Oct;57(5):306-9. doi: 10.1007/BF02197551.
The purpose of the present investigation was to measure the effect of tooth intrusion and extrusion on pulpal blood flow in man. The flow changes were measured in 10 lateral incisors (6 subjects) by means of laser Doppler flowmetry (Perimed, Sweden) applied on the buccal surface through metal tubes bonded to the teeth. Brackets were bonded onto teeth 13 and 23, and intrusive and extrusive forces of 2 N were applied in random order to the experimental tooth for 5 min before unloading. The contralateral tooth served as a control. Extrusion of the teeth gave no significant changes in pulpal blood flow during loading or unloading. However, intrusion of the teeth reduced the pulpal blood flow by 20% during the first minute after force application. The pulpal blood flow gradually increased towards the preloading flow values for the next 4 min, and was returned to the prestimulus level 3 min after unloading. In conclusion orthodontic intrusion of teeth with a 2 N force evoked a temporary reduction in the pulpal blood flow, whereas extrusion had no effect on the pulpal blood flow.
本研究的目的是测量牙齿压低和伸长对人体牙髓血流的影响。通过将激光多普勒血流仪（瑞典Perimed公司）经粘结在牙齿上的金属管作用于颊面，对10颗侧切牙（6名受试者）的血流变化进行测量。在13和23号牙上粘结托槽，在加载前以随机顺序对实验牙施加2 N的压低力和伸长力各5分钟，然后卸载。对侧牙齿作为对照。牙齿伸长在加载或卸载过程中牙髓血流无显著变化。然而，牙齿压低在施加力后的第一分钟使牙髓血流减少了20%。在接下来的4分钟内，牙髓血流逐渐朝着加载前的血流值增加，并在卸载后3分钟恢复到刺激前水平。总之，用2 N的力进行正畸牙齿压低会引起牙髓血流的暂时减少，而伸长对牙髓血流没有影响。
