Chung PY, et al. - Authors gauged the efficacy of platelet-rich plasma (PRP) injection after arthrocentesis or arthroscopy in patients with temporomandibular joint osteoarthritis. They searched the electronic databases (PubMed, EMBASE, Scopus, and Cochrane Library) for reports up to July 30, 2018. In pain reduction for temporomandibular joint osteoarthritis in the long term, adjuvant efficacy to arthrocentesis or arthroscopy was provided by PRP injection. Moreover, significantly better reduction in pain was seen with PRP injection compared to hyaluronic acid (HA) injection, saline injection, or no injection.