Evaluation of lignocaine HCl as a therapeutic and diagnostic tool in myofascial pain dysfunction syndrome and internal derangement

Background: Myofascial pain syndrome MPS is one of the most common causes of chronic musculoskeletal pain. It clinically presents with hypersensitive points in the muscle called "trigger points". Most of the time it remains undiagnosed/undertreated and this leads to severity in symptoms. Deactivation/elimination of trigger points (TrPs) remains the cornerstone of myofascial pain dysfunction syndrome (MPDS) management. The most commonly employed techniques clinically are dry needling of the TrP, local anesthetics or saline injections into TrP, spray and stretch, and ultrasound/electrogalvanic stimulation. Although peripheral nerve blocks are widely used for chronic pain management, their role in myofascial pain dysfunction syndrome is not yet well established. Our study aims to demonstrate the role of mandibular nerve block using lignocaine hydrochloride in the management of MPDS.

Materials and method: Our study is a single-centered randomized control trial performed to evaluate the diagnostic and therapeutic role of mandibular nerve block in treating myofascial pain dysfunction syndrome. A total of 20 subjects fulfilling the inclusion criteria were enrolled in the study. Clinical parameters (pain, mouth opening, and mandibular deviation) were assessed at each follow-up appointment.

Result: All of our patients had significant pain relief at the end of 1 month (P < 0.001), and a substantial improvement in mouth opening is also noted (P < 0.001). There was a significant improvement in deviation immediately after nerve block, and further gradual improvement was observed during each follow-up.

Conclusion: Our study confirmed the role of mandibular nerve block in myofascial pain management. The diagnostic value of mandibular nerve block in differentiating MPDS from internal derangement is also highlighted.