Effect of bone marrow mesenchymal stem cells on healing of temporomandibular joints in rats with induced rheumatoid arthritis.

The healing capacity of bone marrow mesenchymal stem cells (BMMSCs) has been evaluated in various studies. This study aimed to evaluate the effect of BMMSCs on the healing of temporomandibular joints (TMJs) with induced rheumatoid arthritis. Fifty healthy male Sprague Dawley rats were divided into three groups: group I (n = 10), negative control; group II (n = 20), positive control (induction of arthritis by adjuvant followed by intravenous injection of 0.1 ml of PBS); and group III (n = 20), intervention (as for group II but injected intravenously with 1 × 10 cells ml of BMMSCs suspended in PBS). Half of the rats in each group were euthanized 3 wk after the start of the experiment and the other half was euthanized after 5 wk. Group I revealed normal TMJ features. Group II showed thickening of disc, thinning of cartilage, disordered bone trabeculae, and decreased in mean % area staining positive of collagen fibers at 3 wk, while at 5 wk these effects were more aggravated. Group III showed nearly normal thickness of disc and condylar cartilage, nearly normal arrangement of bone trabeculae and regenerated collagen fibers at 3 wk, while after 5 wk the TMJ features were almost normal. Two-way anova revealed statistically significant differences between groups. Thus, treatment of induced rheumatoid arthritis with BMMSCs shows promising results that need to be further investigated in humans.