The evaluation of the efficacy of injectable platelet-rich fibrin and corticosteroid injections in the treatment of internal temporomandibular joint disorders

Objective: The objective of this study was to retrospectively evaluate and compare the clinical effectiveness of single-dose, single-session intra-articular injections of corticosteroids and injectable platelet-rich fibrin in patients with painful temporomandibular joint disorder diagnosed with disc displacement with reduction. Materials and Methods: This study was designed as a retrospective, comparative, and observational analysis. It was conducted through the review of electronic medical records and clinical follow-up forms of patients who presented with temporomandibular joint pain to the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Başkent University, between 2021 and 2022, and who underwent unilateral intra-articular injection therapy (injectable platelet-rich fibrin or corticosteroid). The study was planned in accordance with the Declaration of Helsinki and approved by the Research Ethics Committee of Başkent University, Faculty of Medicine and Health Sciences (D-KA23/24). Patients with a preoperative diagnosis of unilateral disc displacement with reduction confirmed by magnetic resonance imaging were included. All patients received intra-articular injections following the standard protocol: either 2 ml of injectable platelet-rich fibrin or a mixture of 40 mg lyophilized powdered methylprednisolone with 2 ml prilocaine. Clinical evaluation parameters included maximum mouth opening, lateral mandibular movement, pain intensity, and presence of joint clicking. Patients were included in the study if they had available records for the preoperative period and postoperative follow-ups at 1 week, 1 month, and 3 months. Statistical analyses were performed using generalized linear mixed-effects models and post-hoc analysis. Results: In both groups, significant postoperative improvements were observed in maximum mouth opening, lateral mandibular movement, and pain scores (p<0.001). Pain reduction occurred earlier in the corticosteroid group, whereas in the i-PRF group, the decrease started later but demonstrated a more sustained pattern. No statistically significant difference was detected between the two groups in terms of overall treatment efficacy (p>0.05). Maximum mouth opening increased significantly in both groups: in the corticosteroid group, it improved from 35.2 mm to 38.9 mm, with the greatest gain observed during the first postoperative week; in the i-PRF group, it increased from 37.2 mm to 41.2 mm, with the most pronounced improvement recorded between the 1st and 3rd months (p<0.001). A decreasing trend in joint clicking frequency was noted in both groups; however, this change did not reach statistical significance (p>0.05). A strong correlation was observed between right and left lateral movements (r=0.58), indicating that unilateral injections contributed to bilateral functional improvement. Conclusion: Intra-articular injections of corticosteroids and injectable platelet-rich fibrin are both effective methods for achieving short- and medium-term pain control and functional improvement in patients with temporomandibular joint disorders involving disc displacement with reduction. While corticosteroid injection provides rapid symptomatic relief, injectable platelet-rich fibrin supports biological healing processes and offers long-term functional benefits. Therefore, injectable platelet-rich fibrin can be considered a safe and effective biological alternative among minimally invasive treatment options for temporomandibular joint disorders.