Efficacy of intra-articular opioid injections for managing temporomandibular joint nociception: a systematic review

This systematic review evaluated randomized controlled trials (RCTs) investigating the effectiveness of intra-articular opioid injections for managing temporomandibular joint (TMJ) pain. A comprehensive search of indexed databases and Google Scholar was conducted following PRISMA guidelines. Included studies assessed self-reported TMJ pain and maximum mouth opening (MMO) as primary and secondary outcomes, respectively. Risk of bias (RoB) was evaluated using the Cochrane tool, and evidence certainty was rated using the GRADE framework. Ten RCTs met the inclusion criteria, with follow-up periods ranging from 30 minutes to 6 months. Six trials demonstrated significant pain reduction after opioid injections, while one reported no difference following morphine use. Another study found mepivacaine more effective than morphine or saline. Regarding MMO, one trial showed no effect of morphine, whereas two trials found that 1 mg morphine or 1 ml buprenorphine led to greater improvements than 0.1 mg morphine. In three trials, opioids enhanced MMO more than sodium hyaluronate. All studies exhibited low RoB. Certainty of evidence was moderate in six RCTs and low in three. There is no credible evidence for the benefit of intra-articular opioid-injections for managing TMJ nociception. www.crd.tork.ac.uk/prospero identified is CRD42024598035. <b>What We Did:</b> We wanted to find out if injecting opioids into the jaw joint (JJ) helps reduce pain in people with jaw joint problems. <b>How We Did It:</b> We examined multiple scientific databases for interventional studies that tested the effectiveness of opioid injections for pain in the JJ. We only included studies done in humans and included a group in which, sham treatment was done. We also assessed the quality of the studies and analyzed their findings. <b>What We Found:</b> We reviewed 10 studies. Most of them showed that opioid injections helped reduce pain. However, one study found no pain relief when opioids were mixed with numbing medicine. Another study showed that higher doses of opioids helped people open their mouths more easily. The overall quality of the studies was not strong because they used different methods. <b>Conclusions:</b> Opioid injections seem to help with JJ pain, but differences in study methods make it hard to be sure. More high-quality research is needed to confirm how well opioid injections work for JJ pain.