DO BONE MARROW MESENCHYMAL STEM CELLS (BMMSCS) APPLICATION REDUCE ORTHODONTIC RELAPSE?

The presented study aimed at investigating the effect of BMMSCs on the rate of orthodontic relapse in rats both radiographically and histologically. Twenty males, eight weeks old and Wistar rats with their maxillary central incisors had undergone a two-week distal orthodontic movement. The distally moved central incisors were temporarily fixed using a wireresin splint retainer for one week. After retainer removal, the rats were subdivided into four equal groups: Group (1) (C) without any intervention, to act as the baseline control group. Group (2) (SC) bone marrow mesenchymal stem cells (BMMSCs) were applied on the mesial aspect of the roots of maxillary central incisors. The rats were euthanized at four days, 1, 2, 3 and 4 weeks after retention removal. Relapse percentage and bone mineral density were evaluated by using cone-beam computed tomography. Histological analyses were done using hematoxylin & eosin stain and Masson trichrome stains, respectively. Vasculazation and new collagen fibers formation were assessed histologically. The C group significantly showed the highest relapse percentage throughout the experiment periods (p-value £ 0.05), while the SC group showed the least relapse. C group showed the highest bone density significantly through most of the experiment periods. (p-value £ 0.05) at the mesial aspect, while the SC group showed the highest bone density significantly through most experiment periods. (p-value £ 0.05) at the distal aspect. In conclusion, based on the radiographic and histological results of the present study, we conclude the following: 1. The injection of BMMSCs at the pressure side had positive effects remodeling of PDL and decreasing but not inhibiting the rate of relapse. 2-BMMSCs showed good PDL remodeling at both pressure and tension sides. [ABSTRACT FROM AUTHOR]