The efficacy of intra-articular morphine injections in arthrogenous temporomandibular joint pain: a systematic review of randomized controlled trials

Abstract

Objective: This systematic review aimed to evaluate and compare the analgesic efficacy of intra-articular morphine versus other agents in managing arthrogenic TMJ disorders.

Study design: The review adhered to PRISMA guidelines and was registered in PROSPERO (CRD420251011088). A comprehensive search was conducted across PubMed, EMBASE, Scopus, Web of Science, and OVID for randomized controlled trials (RCTs) published up to March 2025. Eligible studies included adults with TMJ-related orofacial pain receiving intra-articular morphine compared to other analgesics. Pain outcomes, especially post-treatment Visual Analog Scale (VAS) scores, were synthesized descriptively due to high heterogeneity.

Results: Seven RCTs were included, with sample sizes ranging from 21 to 53. Most studies showed that intra-articular morphine provided superior or comparable pain relief relative to control agents like tramadol, bupivacaine, and saline. Morphine was associated with longer-lasting analgesia and reduced need for rescue medications. Adverse effects were minimal and non-serious.

Conclusion: Intra-articular morphine injections may be a safe and effective option for managing arthrogenic TMJ pain, offering durable analgesia. This review highlights the need for larger, well-designed trials to standardize protocols and confirm long-term outcomes.