Expression of Dickkopf-related Protein 1 in Patients with Temporomandibular Osteoarthritis after Treatment with Hyaluronic Acid.

We previously reported that the increased expression of Dickkopf-related protein 1 (DKK1) is positively related to vascular endothelial growth factor in the synovial fluid from patients with temporomandibular joint disorders (TMDs). DKK1 is involved in angiogenic activities in the TMD synovium in vitro, but the expression of DKK1 after treatment of TMD-osteoarthritis (TMD-OA) with hyaluronic acid (HA) remains unknown. In this study, we assessed the expression of DKK1 in the synovial fluid of TMD-OA patients before and after treatment with HA via enzyme-linked immunosorbent assay. We also investigated the role of DKK1 in TMD-OA via immunohistochemical staining. The relationship between the expression of DKK1 and the clinicopathological characteristics was determined by Pearson analysis. The results showed that the expression of DKK1 was significantly decreased after treatment with HA. Correlation analyses indicated that the expression of DKK1 in the TMD-OA samples was closely correlated with mouth opening and pain. These findings suggest that DKK1 could play an important role in the pathogenesis and treatment of TMD. Reduction of the pain by HA treatment may be correlated with the decreased expression of DKK1.