功能性下颌偏斜青春期模型大鼠髁突软骨中血管内皮细胞生长因子的表达

Expression of vascular endothelial growth factor in condylar cartilage of rat models of functional mandibular deviation in puberty

背景:对于功能性下颌偏斜是否会导致骨性的下颌偏斜以及发生功能性下颌偏斜后下颌骨的生长方式是否会发生改变,目前尚存在争议。血管内皮细胞生长因子能够使内皮细胞的渗透性增加、刺激血管内皮细胞的有丝分裂、促进血管生成以及调节骨的形成。目的:探索大鼠功能性下颌偏斜对其髁突软骨中血管内皮细胞生长因子表达的影响及意义。方法:选4周龄雄性SD大鼠60只,随机分为对照组(n=20)和实验组(n=40)。实验组大鼠佩戴作者所在课题组自制镍铬合金上前牙冠套,使下颌发生功能性左偏(2.1±0.3)mm,模拟功能性下颌偏斜。结果与结论:造模后7-28 d功能性下颌偏斜模型大鼠髁突软骨矢状向后部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧减少;造模后14-28 d功能性下颌偏斜模型大鼠髁突软骨矢状向中部及冠状向中部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧减少,但与对照组接近;造模后14-28 d功能性下颌偏斜模型大鼠髁突软骨冠状向外部区域偏斜侧血管内皮细胞生长因子的阳性细胞数量较非偏斜侧和对照组减少。说明青春期大鼠发生功能性的下颌偏斜后,双侧髁突软骨中的血管内皮细胞生长因子表达存在差异,导致软骨内的成骨活动发生变化,进而可能使大鼠下颌骨的正常生长发育受到影响,提示应尽早矫治功能性下颌偏斜。

BACKGROUND：Whether the functional mandibular deviation wil cause osteal mandibular deviation and whether the mandibular growth pattern wil change are stil controversial. Vascular endothelial growth factor can increase the endothelial permeability, stimulate endothelial cel mitosis and promote angiogenesis and regulate the formation of bone. OBJECTIVE：To investigate the effect of functional mandibular deviation on the expression levels of vascular endothelial growth factor in condylar cartilage in growing rats. METHODS：Sixty four-week-old male Sprague-Dawley rats were randomly divided into control group （n=20） and experimental group （n=40）. Each animal in experimental group received a nichrome appliance which was designed by our team. Lower mandible suffered from left functional deviation （2.1±0.3） mm to simulate functional mandibular asymmetry. RESULTS AND CONCLUSION：The number of vascular endothelial growth factor-positive cels in the sagittal posterior deviation region of rats with functional mandibular deviation was less than that in the non-deviation region at 7-28 days after model establishment. The number of vascular endothelial growth factor-positive cels was less in the sagittal central and coronal central deviation region than in the non-deviation region in rats with functional mandibular deviation at 14-28 days after model establishment, but was close to the control group. The number of vascular endothelial growth factor-positive cels was less in the coronal lateral deviation region than in the non-deviation region and control group in rats with functional mandibular deviation at 14-28 days after model establishment. These results indicated that after the mandible functional lateral deviation in adolescent rats, the expression of vascular endothelial growth factor was different in bilateral condylar cartilage, caused the alterations in osteoblast activity in cartilage, and possibly affected the normal growth and development of rat mandible, suggesting that functional mandibular deviation should be corrected as early as possible.