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目的:Micro-CT观测骨皮质切开辅助正畸治疗中牙齿移动速率和牙槽骨结构的改变。方法:选用75只4~6周龄的雄性SD大鼠,随机分为3组:组1:牙槽骨皮质切开辅助正畸(CO+TM),组2:传统正畸(TM),组3:单纯牙槽骨皮质切开(CO),按照时间点(加力4、7、14、21、28d后)处死实验动物并进行Micro-CT扫描,测量牙移动距离;三维重建后测量牙颈部、根中部、根尖部3个平面张力侧及压力侧共6个区域的牙槽骨骨密度及骨体积。结果:1)牙移动距离:初期TM组高于CO+TM组,在第14、21、28天时,CO+TM组明显高于TM组(P<0.05)。速率:4~7d时TM组大于CO+TM组,之后小于CO+TM组,组间比较P<0.05。2)骨密度:4、7、21、28d时远中骨密度CO+TM组与CO、TM组比较持续下降,TM组则先下降后上升,CO组稳定于0左右(P<0.05)。3)骨体积:CO+TM组近中骨体积始终呈下降趋势,TM组近中骨体积自加力4d后持续缓慢升高。结论:牙槽骨骨皮质改良切开术辅助正畸可以在术后14~28d内增加正畸牙移动距离;牙槽骨远中侧骨密度降低明显,压力侧骨体积下降,张力侧骨体积上升,骨改建活跃,区域性加速现象在21d时最明显。
Objective: Micro-CT was used to observe the rate of tooth movement and alveolar bone structure in corticotomy assisted orthodontic treatment. Methods: Seventy-five male Sprague-Dawley rats aged 4 to 6 weeks were randomly divided into three groups: Group 1: Alveolar cortical osteo-accessory osteoarthritis (CO + TM), Group 2: Traditional orthodontics Group 3: Simple alveolar bone cortical dissection (CO), the experimental animals were sacrificed at 4, 14, 14, 21 and 28 days after loading, and the micro-CT scanning was performed to measure the tooth movement distance; The alveolar bone density and the bone volume in the three planes of the cervical, root, middle root and root apex were measured in 6 areas. Results: 1) Teeth movement distance: The initial TM group was higher than the CO + TM group, and the CO + TM group was significantly higher than the TM group on the 14th, 21st and 28th days (P <0.05). At 4 ~ 7d, the TM group was larger than the CO + TM group, and later than the CO + TM group (P <0.05.2) CO, TM group continued to decline, TM group first decreased and then increased, CO group stabilized at about 0 (P <0.05). 3) Bone volume: The bone mass in the CO + TM group tended to decrease all the time, and the volume of the proximal and middle bone in the TM group continued to increase slowly after 4 days. Conclusions: Alveolar bone cataract surgery assisted orthodontics can increase the orthodontic tooth movement distance within 14 ~ 28 days after operation; the bone density of distal alveolar bone decreased significantly, the pressure side of the bone volume decreased, the tension side of the bone volume Rise, active bone remodeling, the phenomenon of regional acceleration in 21d most obvious.