声动力刺激调整破骨细胞发生过程对正畸牙移动的影响

The effects of acoustic dynamic stimulation on the development of osteoclast on orthodontic tooth movement

目的在体内、外实验中采用超声波刺激颌骨骨髓间充质成纤维细胞,观察其条件培养基诱导破骨细胞形成的效率,确定超声波功率、频率与破骨细胞形成效率的关系,并在正畸牙移动动物模型中探讨超声波对牙齿速率的影响。方法固定功率(30 mW/cm^(2))下,使用三种频率的超声波(45 KHz、250 KHz、1.5 MHz)刺激体外培养的颌骨骨髓间充质成纤维细胞,取上清液制备条件培养基,诱导破骨细胞分化;在此基础上,固定45 KHz频率,改变声功率(30 mW/cm^(2),120 mW/cm^(2)),分别作用于大鼠模型的移动牙齿颊侧皮肤,于3 d、5 d、7 d、14 d测量牙移动距离;通过抗酒石酸酸性磷酸酶(Trap)染色方法计数牙周组织中破骨细胞数量。结果当声功率固定为30 mW/cm^(2)时,经45 KHz的超声波处理的成纤维细胞,能诱导最多数量破骨细胞形成。当频率固定为45 KHz,经超声波处理的大鼠,牙齿移动速率显著高于未经超声波处理的对照组,且受压侧牙槽骨中破骨细胞的数量显著增加(P<0.05);而120 mW/cm^(2)超声波处理组中,牙齿移动速率和破骨细胞形成效率,皆显著高于30 mW/cm^(2)组(P<0.05)。结论在一定范围内超声波能通过作用于颌骨骨髓间充质成纤维细胞,促进破骨细胞形成,加速正畸牙移动;该作用随超声波频率降低,功率增高而加强,可能为加速正畸牙移动提供启示。

Objective To investigate the osteoclasts formation induced by fibroblasts from jawbone which was stimulated by ultrasound in vitro or in vivo.Methods Ultrasound with three frequencies(45 KHz,250 KHz,1.5 MHz)but one acoustical power(30 mW/cm^(2))were used to stimulate fibroblasts,respectively,from which the conditioned medium was collected and induced the osteoclast differentiation.Subsequently,the ultrasound with 45 KHz which induced most osteoclasts was applied to the rat orthodontic model,at the acoustical power of 30 mW/cm^(2)or 120 mW/cm^(2).At the 3rd,5th,7th and 14th day,the distance of tooth movement was measured,the osteoclasts in the periodontal tissues were investigated by TRAP staining.Results When the acoustical power was 30 mW/cm^(2),the ultrasound at 45 KHz induced most osteoclasts among three groups in vitro.Furthermore,ultrasound had indeed accelerated the tooth movement,in contrast with controls,and the ultrasound of 120 mW/cm^(2)significantly led to more distance of tooth movement(P<0.05),as well as induced more osteoclasts in periodontal tissues,as compared with the ultrasound of 30 mW/cm^(2)(P<0.05).Conclusion The fibroblasts stimulated by ultrasound could induced more osteoclasts than untreated fibroblasts.It perhaps contribute to the accelerated tooth movement.The acceleration negatively associate with the frequency of ultrasound,but positively associate with the acoustical power.