Patients(n=120) attending The Department of Temporomandibular Disorders and Orthodontics at the Silesian Medical University Poland, Zabrze were enrolled to the study and randomly divided into one of two groups: experimental and control group. Platelet-Rich Plasma(PRP) was prepared for each patient and an intramuscular injections of 0,5 ml PRP into 6 points at each side were performed in experimental group. A follow-up appointment was made after 10 and 20 days and in each visit an injection of PRP or 0,9% NaCl was performed. Pain intensity was measured in NPRS(numeric pain rating scale) and collected data data were analyzed.