下颌前伸对大鼠髁突软骨VEGF表达影响的研究

目的：探讨引导大鼠下颌前伸后，髁突软骨中血管内皮细胞生长因子（VEGF）表达水平的变化。方法：50只35d龄雌性SD大鼠随机分为5组，每组随机分为实验组（5只）和对照组（5只）；实验组大鼠24h佩戴自制功能性矫治器引导下颌前伸；实验后3d、7d、14d、21d和30d分别处死各组大鼠；免疫组化方法检测髁突软骨中VEGF的表达。结果：对照组髁突软骨VEGF表达随时间延长而减弱，后部区域VEGF表达强于前部和中部：实验后第14d，21d和30d实验组VEGF表达强于相应对照组（P〈0．05），其中14d时软骨后部VEGF表达较对照组增强幅度最大。结论：下颌前伸后大鼠髁突软骨细胞VEGF表达增强，说明其参与了软骨内骨化过程。

The expression of vascular endothelial growth factor in the condyle during forward mandibular positioning

Objective: To investigate the temporal pattern of expression of Vascular Endothelial Growth Factor (VEGF) in the condyle of rat during forward mandibular positioning. Method: Fifty 35-day-old female Spague-Dawley(SD) rats were randomly divided into 5 groups.Each group consisted of five rats with bite-jumping appliance and five untreated.One group was sacrificed on days 3, 7, 14, 21 and 30 respectively.VEGF immunostaining was performed to detect the expression level of VEGF. Result: The expression level of VEGF in control groups decreased during the experimental periods with higher expression in posterior region compared to anterior and middle regions.Mandibular advancement in rats caused a gradual increase in the expression of VEGF when compared to the control group(P<0.05),with the highest amount of changes in the posterior region on Day 14. Conclusion: Mandibular advancement in rats caused cellular changes of condyle,which led to increased VEGF expression and endochondral ossification.