超声波加速正畸牙移动的实验动物研究

目的:在大鼠正畸模型中,对第一磨牙牙周组织施加超声波振动,观察超声波是否能加速正畸牙移动。方法:选用30只SD大鼠,建立以中切牙为支抗,移动单侧第一磨牙的正畸模型,分为常规正畸组和超声波振动组。于加力第7、14、28天测量牙移动距离,HE染色,trap染色破骨细胞计数,Masson染色观察第一磨牙牙周组织的变化。结果:牙周组织接受超声波振动刺激后,大鼠第一磨牙在第7、14、28天移动速率显著高于常规正畸组(P<0.05);同时可观察到超声波振动组中TRAP阳性的破骨细胞显著多于常规正畸组(P<0.05)。而Masson染色则显示,在加力第7天,常规正畸组和超声波振动组中,皆出现新生骨;但第14天时,前者新骨形成更加明显;直到第28天超声波后者出现更大规模的成骨反应。结论:超声波显著、并持续地增加牙周组织内破骨细胞形成数量,此效应可能导致了大鼠正畸模型的牙齿移动的加速,成功建立超声波加速正畸牙移动的实验动物模型。

Animal Study on the Ultrasound Accelerated Orthodontic Tooth Movement.

Objective: To observe whether ultrasound could accelerate tooth movement in a rat orthodontic model. Methods: In this study, 30 rats were randomly divided into 2 groups, with 5 rats at each time point. Orthodontic appliances were placed between the maxillary first molars and central incisors. The rats were randomly divided into 2 groups: group 1 was normal treatment and group 2 was ultrasound treatment. The rats were sacrificed at different time points (t=7, 14, 28 days), the distances of tooth movement were measured and histologically observed. Results: The ultrasound significantly increased orthodontics tooth movement distances at day 7, 14, 28 compared with conventional orthodontic group. Histological observation demonstrated that the count of osteoclasts in the experimental group was significantly more than that in the conventional orthodontic group. Via Masson staining, new bone formation was found in both groups at the 7th day; after 14 days, there were more new bone formation in the group 1; 28 days later, more new bone formation was found in the group 2. Conclusion: The results suggest that the ultrasound can significantly increase the osteoclastogenesis around the moving tooth. This effect may induce the accelerated tooth movement.