Rabie A B M, Leung F Y C, Chayanupatkul A, Hägg U
Hard Tissue Research, Faculty of Dentistry, The University of Hong Kong, SAR, China.
Angle Orthod. 2002 Oct;72(5):431-8. doi: 10.1043/0003-3219(2002)072<0431:TCBNAB>2.0.CO;2.
The aim of the present study was to investigate the temporal pattern of expression of VEGF (Vascular Endothelial Growth Factor) and new bone formation in the condyle during forward mandibular positioning. The importance of vascularization during endochondral ossification was investigated during natural growth of the condyle and compared to that after forward mandibular positioning. The goal was to further our understanding of the cellular responses during functional appliance therapy with a view to extending the experiment into maturity. One hundred and fifty 35 days old Sprague-Dawley rats, 100 fitted with a bite-jumping appliance and 50 untreated, were divided into 10 groups. One group was sacrificed on each of experimental days 3, 7, 14, 21, 30, 33, 37, 44, 51 and 60 respectively. Sagittal sections were cut and stained with VEGF antibodies and Periodic acid and Schiff's reagent (PAS). Each section was quantitatively analyzed with a computer assisted analyzing program and the temporal sequence of expression of VEGF and new bone formation during natural growth and after mandibular forward positioning was compared. There was significant increase in both vascularization and mandibular bone growth upon forward mandibular positioning and the highest amount of both were expressed in the posterior region of the condyle. The highest acceleration of vascularization preceded that of new bone formation. Thus, forward mandibular positioning was found to solicit a sequence of cellular events leading to increased vascularization and subsequently new bone formation resulting in enhanced condylar growth.
本研究的目的是调查下颌前伸定位过程中髁突内血管内皮生长因子（VEGF）的表达时间模式和新骨形成情况。在髁突自然生长过程中研究软骨内成骨过程中血管化的重要性，并与下颌前伸定位后的情况进行比较。目的是进一步了解功能性矫治器治疗期间的细胞反应，以便将实验扩展到成熟期。150只35日龄的Sprague-Dawley大鼠，100只佩戴咬合跳跃矫治器，50只未处理，分为10组。分别在实验第3、7、14、21、30、33、37、44、51和60天处死一组。制作矢状切片，用VEGF抗体以及高碘酸和席夫试剂（PAS）染色。用计算机辅助分析程序对每个切片进行定量分析，并比较自然生长和下颌前伸定位后VEGF表达和新骨形成的时间顺序。下颌前伸定位后血管化和下颌骨生长均显著增加，两者的最高量均在髁突后部表达。血管化的最高加速先于新骨形成。因此，发现下颌前伸定位引发一系列细胞事件，导致血管化增加，随后新骨形成，从而促进髁突生长。
