To study the effect of platelet-rich plasma (PRP) injections on pain reduction in patients with temporomandibular joint osteoarthritis (TMJ OA).
The authors performed a comprehensive search of the MEDLINE, PubMed, and Web of Science databases to retrieve RCTs published up to July 2018. Pain outcomes (visual analog scale scores) were extracted to assess the effect of PRP injections on TMJ OA. All data analyses were conducted using RevMan 5.3.
Six studies were included. According to the results of these trials, intra-articular injections of PRP were more effective than placebo for pain reduction (6 months postinjection: mean difference [MD] -2.82, 95% CI -3.39 to -2.25, P < .00001; 12 months postinjection: MD -3.29; 95% CI -4.07 to -2.52, P < .00001). Additionally, the comparison between PRP and hyaluronic acid injections showed a statistically significant difference in pain reduction in support of PRP (MD -0.81; 95% CI -1.22 to -0.40; P = .0001) at 12 months postinjection. All trials revealed a moderate risk of bias.
Based on current evidence, PRP injections may reduce pain more effectively than placebo injections in TMJ OA at 6 months (level of evidence: moderate) and 12 months (level of evidence: moderate) postinjection. This significant difference in pain reduction could also be seen when PRP was compared to hyaluronic acid at 12 months postinjection (level of evidence: low). It can be cautiously interpreted that PRP has a beneficial effect on the relief of TMJ OA pain. Large-scale, low-bias RCTs are needed to test whether PRP injection should be a routine treatment for patients with TMJ OA.