The authors designed a randomized, controlled, double-blind clinical trial after the ethical approval by the University Ethics Committee. The patients with temporomandibular joint osteoarthritis (TMJ-OA) randomly assigned one of the two treatment groups: intra-articular injection of injectable platelet-rich fibrin (i-PRF) after arthrocentesis procedure as i-PRF group and arthrocentesis procedure alone as control group. The primary outcome variable was pain levels at preoperatively, and postoperatively at 1st, 2nd, 3rd, 6th and 12th month. The secondary outcome variables included maximum mouth opening (MMO), lateral and protrusive movements.

The authors designed a randomized, controlled, double-blind clinical trial after the ethical approval by the University Ethics Committee. The patients with TMJ-OA randomly assigned one of the two treatment groups: intra-articular injection of i-PRF after arthrocentesis procedure as i-PRF group and arthrocentesis procedure alone as control group. All treatment procedures were completed by the same experienced surgeon under the local anesthesia. The procedure of arthrocentesis was performed using the standard technique and after arthrocentesis procedure, the i-PRF injection was performed in the test group.

The primary outcome variable was pain levels at preoperatively, and postoperatively at 1st, 2nd, 3rd, 6th and 12th month. The secondary outcome variables included maximum mouth opening (MMO), lateral and protrusive movements.

Inclusion Criteria:

• patients with osteoarthritis (OA) of one or two temporomandibular joint (TMJ)
• maximum mouth opening less than 35 mm
• impeded protrusive and lateral movements
• localized pain of the affected joint

Exclusion Criteria:

• systemic or malignant diseases affecting TMJ-OA assessment
• previous invasive or surgical treatments of TMJ unrelated to OA
• edentulous patients
• pregnancy