Tsuka Yuji, Kunimatsu Ryo, Gunji Hidemi, Nakajima Kengo, Hiraki Tomoka, Nakatani Ayaka, Tanimoto Kotaro
Department of Orthodontics, Division of Oral Health and Development, Hiroshima University Hospital.
Department of Orthodontics, Applied Life Sciences, Hiroshima University Institute of Biomedical & Health Sciences.
J Oral Sci. 2019 Mar 28;61(1):67-72. doi: 10.2334/josnusd.17-0472. Epub 2019 Feb 1.
The aim of this study was to evaluate the effects of a fiberotomy-like procedure using Er:YAG laser irradiation on the velocity of orthodontic tooth movement. To produce experimental tooth movement in rats, orthodontic force was applied to the upper first molars with a nickel-titanium closed coil. The right molars were irradiated with an Er:YAG laser while the non-irradiated left molars were used as controls. The rats were sacrificed at 4 weeks after the start of tooth movement and the distance between the mesial side of the second molar and the distal side of the upper first molar was measured on CT images. The amount of tooth movement was significantly greater in the irradiation group than in the control group. The TRAP-positive nuclei count at the pressure site was higher in the laser-irradiation group than in the control group. Expression of RANKL and ALP was higher at the mesial-coronal pressure site in the laser-irradiation group than in the control group. In addition, expression of OPG was higher at the pressure site in the control group than in the laser-irradiation group. These results suggest that a fiberotomy-like procedure using an Er:YAG laser stimulates osteoclasts and osteoblasts and may promote bone metabolism in the context of experimental tooth movement.
本研究的目的是评估使用铒钇铝石榴石（Er:YAG）激光照射进行类似纤维切断术的操作对正畸牙齿移动速度的影响。为了在大鼠中产生实验性牙齿移动，用镍钛闭合线圈对上颌第一磨牙施加正畸力。右侧磨牙用Er:YAG激光照射，未照射的左侧磨牙作为对照。在牙齿移动开始4周后处死大鼠，并在CT图像上测量第二磨牙近中侧与上颌第一磨牙远中侧之间的距离。照射组的牙齿移动量明显大于对照组。激光照射组压力部位的抗酒石酸酸性磷酸酶（TRAP）阳性细胞核计数高于对照组。激光照射组近中-冠部压力部位的核因子κB受体活化因子配体（RANKL）和碱性磷酸酶（ALP）表达高于对照组。此外，对照组压力部位的骨保护素（OPG）表达高于激光照射组。这些结果表明，使用Er:YAG激光进行类似纤维切断术的操作可刺激破骨细胞和成骨细胞，并可能在实验性牙齿移动的情况下促进骨代谢。
