TMJ: Arthrocentesis with injected fibrin further reduces pain

The contribution of i-PRF in the treatment of temporomandibular disorders: a meta-analysis

Temporomandibular joint disorders (TMD) represent a prevalent craniofacial pathology, often combining chronic pain and limitations in mandibular movements. Although arthrocentesis is a validated minimally invasive procedure for refractory internal derangements, the persistence of symptoms and the risk of clinical recurrence necessitate the search for biological adjuvants capable of promoting tissue healing.

i-PRF (injectable Platelet-Rich Fibrin) is part of this regenerative dynamic. This autologous platelet concentrate, prepared without anticoagulant, releases growth factors and anti-inflammatory mediators in a sustained manner. This systematic review with meta-analysis of randomized clinical trials (RCTs) aims to precisely evaluate the clinical efficacy of intra-articular i-PRF injection combined with arthrocentesis.

The study is based on the hypothesis that such a combination would allow for a superior improvement in pain intensity and mandibular function compared to arthrocentesis alone or conventional treatments. The analysis focuses on strict criteria: the evolution of pain scores via the visual analogue scale (VAS), maximum mouth opening (MMO), and the impact on oral health-related quality of life.

Methodology: from literature search to statistical rigor

This systematic review and meta-analysis, conducted according to PRISMA guidelines and the Cochrane Handbook, synthesises data from 9 randomised clinical trials (RCTs) selected after an exhaustive search up to 1 May 2026. The authors queried four major databases — PubMed (39), Scopus (52), Web of Science (41) and Cochrane CENTRAL (19) — and completed this investigation with a manual analysis of reference lists (backward citation analysis).

Le protocole de sélection s'est appuyé sur les critères PICO suivants :

• Population: Patients suffering from symptomatic temporomandibular disorders (TMD) (internal derangement).
• Procedure: Arthrocentesis of the upper joint space (lavage with Ringer's lactate or physiological saline) coupled with an intra-articular injection of injectable platelet-rich fibrin (i-PRF).
• Comparison: Arthrocentesis alone or conservative treatment.
• Evaluation criteria: Evolution of pain (VAS scale), maximum mouth opening (MMO), lateral excursions and quality of life (OHIP-14).

To ensure the reliability of the results, the authors used a random-effects model (mean difference, 95% CI), coupled with a trial sequential analysis (TSA) to verify whether the cumulative sample size allowed for a definitive conclusion on pain. The quality of evidence was graded using the GRADE scale.

Study selection and analysis protocol

The systematic search conducted by the authors initially identified 151 records across four major databases. After removing 27 duplicates, 124 articles underwent screening of titles and abstracts. Following this process, 15 articles were subjected to a full-text evaluation.

Ultimately, 9 randomized controlled trials (RCTs) were included in the quantitative analysis (meta-analysis). This rigorous selection, limited to RCTs, allows for the evaluation of the effectiveness of arthrocentesis combined with i-PRF with a high level of evidence for the practitioner.

Database	Results (N)
PubMed	39
Scopus	52
Web of Science (WoS)	41
Cochrane Central (CENTRAL)	19
Total identified	151

Evaluation parameters and statistical methodology

The authors of this review extracted data from 9 studies involving patients suffering from internal derangements of the TMJ. The primary objective was to measure the evolution of the pain score via the visual analogue scale (VAS). Secondary criteria included:

• Maximum Mouth Opening (MMO).
• Lateral excursions (right, left and contralateral).
• The protrusion movement.
• Oral health-related quality of life (OHIP-14).

Data synthesis is based on a random-effects model using the mean difference (MD) with a 95% confidence interval. To ensure the reliability of the conclusions, the authors planned a trial sequential analysis (TSA) to determine whether the accumulated evidence is conclusive, as well as an assessment of the quality of evidence via the GRADE scale.

Subgroup analyses were planned to observe clinical progression at 3, 6, and 9-12 months, while distinguishing between types of pain (at rest, during mastication, and upon palpation). This approach allows for determining whether the addition of i-PRF offers a lasting benefit or a merely transient one following joint lavage.

i-PRF assisted arthrocentesis: a rational biological synergy

Arthrocentesis is the cornerstone of minimally invasive treatment for temporomandibular joint (TMJ) dysfunction, particularly in cases of internal derangement or osteoarthritis. However, the recurrence of symptoms limits its long-term efficacy. This systematic review explores the integration of i-PRF (injectable platelet-rich fibrin) as a biological adjuvant. The primary interest of i-PRF lies in its lack of anticoagulants and its fibrin structure, allowing for a sustained release of growth factors and anti-inflammatory mediators. Unlike PRP, i-PRF offers bioactive mediator release kinetics better suited for intra-articular tissue regeneration.

Methodologically, this study stands out through the use of rigorous validation tools such as Trial Sequential Analysis (TSA) and the GRADE scale to evaluate the strength of recommendations across the nine included studies. This approach aims to address the common limitations in the literature, often characterized by small sample sizes and heterogeneous centrifugation protocols. The focus on concrete clinical outcomes, such as the Visual Analogue Scale (VAS) for pain and Maximum Mouth Opening (MMO), reinforces the relevance of the analysis for daily practice.

Nevertheless, the practitioner should note that the clinical efficacy of this combination relies on the standardization of preparation protocols. Although the hypothesis of superior functional improvement through the addition of i-PRF is biologically supported, the variability of follow-up periods (ranging from 3 to 12 months in the identified studies) requires a cautious interpretation of the results before systematizing the procedure in all cases of internal derangement.

In concrete terms, for the practitioner:

• Preferring i-PRF over PRP: its preparation method without chemical additives and its prolonged release of growth factors make it a superior biological candidate for intra-articular modulation.
• Protocol standardization: the quality of the fibrin concentrate is operator-dependent; ensure strict compliance with centrifugation protocols to guarantee cellular supply.
• Targeted indication: the addition of i-PRF is particularly relevant for patients presenting with symptoms refractory to conventional conservative treatments.

This systematic review, based on 151 records to select 9 randomized controlled trials (RCTs), evaluates the efficacy of arthrocentesis combined with i-PRF in TMJ disorders. The study focuses on the evolution of pain (VAS) and maximum mouth opening (MMO), using rigorous validation tools such as trial sequential analysis (TSA) and the GRADE scale.

Technical lexicon of the study

i-PRF (Injectable Platelet-Rich Fibrin): Second-generation autologous platelet concentrate, centrifuged without anticoagulant. It forms a dynamic fibrin matrix allowing the sustained release of growth factors and leukocytes directly into the core of the temporomandibular joint.

Arthrocentesis: Procedure for washing the upper joint space (often with Ringer's Lactate). It aims to drain biochemical mediators of inflammation and eliminate intra-articular adhesions to restore fluid mandibular kinematics.

MMO (Maximum Mouth Opening): Maximum inter-incisal distance measured in millimetres. It is the major functional assessment criterion for evaluating the effectiveness of regenerative therapies on the limitation of mouth opening.

OHIP-14 (Oral Health Impact Profile-14): Standardised questionnaire measuring the impact of oral health disorders on health-related quality of life. It quantifies the patient's overall perception beyond the simple clinical measurement of pain.

ROB-2 (Risk of Bias 2): Critical appraisal tool from the Cochrane Collaboration used by the authors to analyze the methodological robustness of the randomized clinical trials included in this meta-analysis.

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses): International reference protocol followed for the drafting of this review, ensuring the transparency and reproducibility of the scientific data selection and analysis process.

---

Information intended for healthcare professionals. This content may contain errors or truncated summaries. We recommend always verifying with the original source article. Delynov disclaims all responsibility regarding the use of this information. This document is not intended for patients or the general public.