This study will evaluate whether intra-articular injectable platelet-rich fibrin (i-PRF) is more effective than arthrocentesis alone in treating temporomandibular joint (TMJ) disorders. Patients will be randomly assigned to two groups: one receiving arthrocentesis followed by i-PRF injection, and the other undergoing arthrocentesis only.

Pain intensity (VAS) and maximum mouth opening will be measured at baseline, 1 week, and 1 months. The goal is to determine if i-PRF provides greater pain relief and functional improvement compared with standard lavage.

Temporomandibular joint (TMJ) disorders are a group of conditions that affect the jaw joint and surrounding muscles and ligaments. They can cause pain in the preauricular region, difficulty in opening or closing the mouth, clicking or crepitation sounds during movement, and impaired quality of life. Arthrocentesis, a minimally invasive procedure involving joint lavage, is often used when conservative treatments are not sufficient.

Injectable platelet-rich fibrin (i-PRF) is a second-generation platelet concentrate obtained from the patient's own blood without anticoagulants or additives. It contains high levels of platelets, leukocytes, and growth factors, which may promote tissue regeneration and healing. i-PRF has been used in various oral and maxillofacial procedures, and recent studies suggest that it may improve outcomes in TMJ disorders.

This randomized controlled trial aims to compare the effectiveness of intra-articular i-PRF injection with arthrocentesis alone in patients with TMJ disorders. Patients will be randomly assigned to one of two groups:

Experimental Group (i-PRF): Arthrocentesis followed by intra-articular injection of autologous i-PRF.

Control Group: Arthrocentesis only (joint lavage without any additional injection).

The primary outcome will be the change in pain intensity, measured using the Visual Analog Scale (VAS), and the secondary outcome will be the change in maximum mouth opening (measured in millimeters). Assessments will be performed at baseline, 1 week, and 1 months after treatment.

The study will be conducted at the Department of Oral and Maxillofacial Surgery, Eskişehir Osmangazi University, Turkey. It is expected that i-PRF will provide greater pain reduction and functional improvement compared to arthrocentesis alone, offering a regenerative and low-risk alternative in the management of TMJ disorders.

Inclusion Criteria:

Patients ≥18 years old Diagnosed with temporomandibular joint disorder (TMD) based on clinical and radiological findings Presence of pain, restricted mouth opening, or joint sounds Voluntary participation and signed informed consent

Exclusion Criteria:

Systemic diseases affecting bone/joint healing (e.g., uncontrolled diabetes, rheumatoid arthritis, osteoporosis) Previous TMJ surgery or intra-articular injection Current pregnancy or breastfeeding Coagulopathy or anticoagulant therapy Allergy to hyaluronic acid (for control group) Inability to attend follow-up visits