BACKGROUND:Core decompression can delay early osteonecrosis of the femoral head, but cannot completely repair the necrotic femoral head. Eventualy, femoral head colapse, even bone necrosis, wil occur. OBJECTIVE:To explore the curative effect of implantation of gelatin sponge carrying Foxc2-transfected bone marrow mesenchymal stem cels on the repair of experimental femoral head necrosis in rabbits. METHODS:Forty New Zealand white rabbits were selected, and femoral head necrosis models were prepared successfuly in 24 of 40 rabbits. Then, model rabbits were randomized into four groups: blank control group (n=4) with no treatment, core decompression group (n=4), GFP group (n=8) subjected to core decompression and implantation of gelatin sponge carrying GFP-transfected bone marrow mesenchymal stem cels, and Foxc2 group (n=8) subjected to core decompression and implantation of gelatin sponge carrying Foxc2-transfected bone marrow mesenchymal stem cels. At 1, 2, 4 weeks after implantation, ELISA was used to detect Foxc2 protein levels in the transplanted region. At 4, 8, 12 weeks after implantation, MRI scan of the hip was performed, and femoral head tissues were taken and sliced into sections for hematoxylin-eosin staining to observe bone growth. At 12 weeks after implantation, histomorphometry measurement and transmission electron microscope observation were carried out. RESULTS AND CONCLUSION:At 1, 2, 4 weeks after implantation, Foxc2 was highly expressed in the femoral head in the Foxc2 group, which was significantly higher than that in the GFP group. At 4, 8, 12 weeks, only a few of new bone formed in the core decompression group and GFP group; at 12 weeks, fibrous tissues formed in the decompression channel. New bone formation was evident in the Foxc2 group, and at 12 weeks, the necrotic region was repaired completely. MRI findings showed normal femoral head morphology and signals in the Foxc2 group at 12 weeks, but there were decreased signals of the femoral head in the core decompression group and GFP group. These findings indicate that Foxc2-transfected bone marrow mesenchymal stem cel transplantationvia core decompression has good curative effects on experimental femoral head necrosis in animals.

Objective: To investigate the effect of microencapsulated transgenic bone marrow mesenchymal stem cells (BMSCs) transplantation on early steroid induced osteonecrosis of femoral head (SONFH) in rabbits. Methods: Alginate poly- L-lysine-sodium alginate (APA) microencapsulated transgenic BMSCs with high expression of Foxc2 were prepared by high-voltage electrostatic method. Part of the cells were cultured in osteoblasts and observed by alizarin red staining at 2 and 3 weeks. Forty New Zealand white rabbits were used to prepare SONFH models by using hormone and endotoxin. Thirty two rabbits who were successful modeling were screened out by MRI and randomly divided into 4 groups (groups A, B, C and D, n=8); another 6 normal rabbits were taken as normal control (group E). The rabbits in group A did not receive any treatment; and in groups B, C, and D were injected with normal saline, allogeneic BMSCs, and APA microencapsulated transgenic BMSCs respectively after core decompression. At 6 and 12 weeks after operation, specimens of femoral head were taken for HE staining to observe bone ingrowth; the expressions of osteocalcin (OCN), peroxisome proliferative activated receptor γ 2 (PPARγ-2), and vascular endothelial growth factor (VEGF) proteins were observed by immunohistochemistry staining. At 12 weeks after operation, the bone microstructure was observed by transmission electron microscope, and the maximum compressive strength and average elastic modulus of cancellous bone and subchondral bone were measured by biomechanics. Results: After 2 and 3 weeks of induction culture, alizarin red staining showed the formation of calcium nodules, and the number of calcium nodules increased at 3 weeks when compared with 2 weeks. The rabbits in each group survived until the experiment was completed. Compared with groups A, B, and C, the trabeculae of group D were more orderly, the empty bone lacunae were less, there were abundant functional organelles, and obvious osteogenesis was observed, and the necrotic area was completely repaired at 12 weeks. Immunohistochemical staining showed that, at 6 and 12 weeks after operation, the expressions of OCN and VEGF in groups A, B, and C were significantly lower than those in groups D and E, while those in groups B and C were significantly higher than those in group A, and in group E than in group D ( P<0.05). The expression of PPARγ-2 was significantly higher in groups A, B, and C than in groups D and E, and in group A than in groups B and C, and in group D than in group E ( P<0.05). At 12 weeks after operation, biomechanical test showed that the average elastic modulus and maximum compressive strength of cancellous bone and subchondral bone in groups D and E were significantly higher than those in groups A, B, and C ( P<0.05); there was no significant difference between groups A, B, and C and between groups D and E ( P>0.05). Conclusion: In vivo transplantation of microencapsulated transgenic BMSCs can repair early SONFH in rabbits.

Objective: To study the effects of the palatal spur and chincup in the early treatment of anterior open bite in patients with Angle class Ⅰ malocclusion. Methods: Electronic search was conducted to find studies about the effects of the palatal spur and chincup in the early treatment of anterior open bite in patients with Angle class Ⅰ malocclusion. Data extraction and risk of bias assessment of included studies were conducted. RevMan5. 3 software was used fore Meta-analysis. Results: 6 clinical trials were qualified to the Meta-analysis. Compared to the control group, there was no significant change of skeletal measurments after treatment (P＞ 0. 05), and no significant change in dental measurments in chincup group (P＞ 0. 05) . While overbite, U1-PP (mm) and L1-MP (mm) were increased (P ＜ 0. 05), U1-NA (°) and L1-NB (°) decreased (P ＜ 0. 05) in the 3 groups of fixed palatal crib, bonded spur associated with the chincup and the removable palatal spur associated with the chincup. Conclusion: Chincup is not effective in the early treatment of the anterior open bite in patients with Angle class I malocclusion. But chincup combined with palatal spur or crib and have a positive effect on the closure of open bite through the palatal clination and extraction of the anterior teeth without influence of molar intrusion and skeletal change.