Therapeutic effect of intra-articular injection of hyaluronic acid and platelet-rich plasma on the expression of salivary matrix metalloproteinases 2 and 9 in tempromandibular internal derrangment patients

Aims and Objectives: Temporomandibular disorder is a broad term for the joint musculoskeletal problems. This study was aimed to assess the therapeutic effect of hyaluronic acid (HA) and platelet-rich plasma (PRP) on salivary matrix metalloproteinases (MMPs) 2 and 9 expression in patients with internal derrangment. Materials and Methods: Fifty-two patients with tempromandibular joint internal derrangment were participated in this study. Patients were separated into two groups: HA and PRP groups. Saliva was obtained before treatment and 6 months after treatment. The expression of MMP-2 and 9 was identified using enzyme-linked immunosorbent assay kit. Results: The expression of both salivary MMP-2 and 9 was significantly decreased after treatment (p = 0.000). A positive correlation was established between MMP-2 and 9 with the mean pain scale and joint click score. However, a negative correlation was found between MMP-2 and 9 with the maximum mouth opening (MMO). Conclusion: Both HA and PRP showed a beneficial therapeutic effect revealed through the reduction of salivary MMP-2 and 9 as an inflammatory biomarkers.