Sawada M, Shimizu N
Department of Orthodontics, Nihon University School of Dentistry, Chiba, Japan.
Eur J Orthod. 1996 Apr;18(2):169-79. doi: 10.1093/ejo/18.2.169.
The most intense endogenous transforming growth factor (TGF)-beta 1 expression was detected in osteoblasts and fibroblasts in the mid-palatal suture 24 hours after the start of palatal expansion with an immunohistochemical technique. Based on these data, local effects of transforming growth factor-beta 1 (TGF-beta 1) in the expanding mid-palatal suture of the rat were examined. Single doses of human recombinant (rhu) TGF-beta 1 (40 and 200 ng, and 1 microgram) were injected into the expanding mid-palatal suture 24 hours after expansion started. Calcein was also injected immediately, and 6 and 12 days after expansion. The width of each calcein label was measured to evaluate bone formation along the suture with bone histomorphometry. In the experimental groups, bone formation during the 12-day expansion period was stimulated significantly (P < 0.05), in a dose-dependent manner, compared with that in the control group. Furthermore, bone formation during the later stage (6-12 days) of the 12-day expansion period, was still significantly higher than that in the control group. In addition, the amount of bone formation in response to a course of 3 injections of 200 ng rhu TGF-beta 1 on days 3, 6, and 9 was almost equal to that induced by a single injection of 200 ng rhu TGF-beta 1 on day 1. These results suggest that TGF-beta 1 may play an important role in bone formation at the active site of the suture in response to rapid palatal expansion and application of TGF-beta 1 during the early stages may induce rapid bone formation.
采用免疫组织化学技术检测发现，在开始腭扩张24小时后，腭中缝的成骨细胞和成纤维细胞中内源性转化生长因子（TGF）-β1表达最为强烈。基于这些数据，研究了转化生长因子-β1（TGF-β1）在大鼠扩张腭中缝中的局部作用。在开始扩张24小时后，将单剂量的人重组（rhu）TGF-β1（40 ng、200 ng和1μg）注射到扩张的腭中缝中。同时立即注射钙黄绿素，并在扩张后6天和12天注射。通过骨组织形态计量学测量每个钙黄绿素标记的宽度，以评估沿缝线的骨形成情况。与对照组相比，实验组在12天扩张期内的骨形成受到显著刺激（P<0.05），且呈剂量依赖性。此外，在12天扩张期的后期（6 - 12天），骨形成仍显著高于对照组。另外，在第3天、第6天和第9天注射3次200 ng rhu TGF-β1所诱导的骨形成量几乎与在第1天单次注射200 ng rhu TGF-β1所诱导的骨形成量相等。这些结果表明，TGF-β1可能在快速腭扩张引起的缝线活跃部位的骨形成中起重要作用，且在早期应用TGF-β1可能诱导快速骨形成。
