Objective: To investigate the expression of TGF-beta 1 mRNA in pubescent Rhesus monkeys' condylar under Class III intermaxillary functional orthopedic force for different lengths of time.
Methods: Six pubescent Rhesus monkey were divided into two test groups and a control group. Monkeys in the test groups were TMAIII while the control groups did not. Histological method (HE staining) and in situ hybridization were employed in this study.
Results: 1. The histological results showed that, compared with the control group, the anterior part of the condyle became thicker while the median part and the posterior part became thinner in 3 months group. However, in 6 months group, the change was similar to 3 months group. 2. The results of in situ hybridization showed that, in control group, TGF-beta 1 mRNA mildly expressed in the anterior part of the condyle while extensively in the median and posterior parts. In 3 months group, TGF-beta 1 mRNA expressed in all parts of condyle; the most intensive expression was in the anterior part. Compared with 3 months group, the expression of TGF-beta 1 mRNA decreased in 6 months group, but the expression in anterior part was stronger than in median and posterior parts.
Conclusion: Under Class III Orthopedic therapy, TGF-beta 1 mRNA probably participated in the endochrondral bone remodeling in the condyle, and the expression was closely related to loading time. In 3 months group, the expression of TGF-beta 1 mRNA was stronger than that in 6 months group. It was inferred that the remodeling of endochrondral bone was more active in 3 months group.