The use of mandibular nerve block in unilateral mandibular fracture to evaluate the mouth opening for assessment of airway

BACKGROUND: Facial area is one of the most frequently injured area of the body, accounting for 23–97% of all facial fractures. Treatments under general anesthesia as those for maxillofacial fractures or infections is a highly complicated and a major challenging task in trismus associated patients. The main culprit in trismus is the increase muscle tone of masticatory muscles which are supplied via the mandibular nerve, blocking which could help increase the mouth opening thus, changing the whole of airway management. MATERIAL AND METHOD: A prospective study was done on 50 patients of ASA grade I-II with unilateral mandibular fracture with trismus posted for maxillofacial surgery. Mandibular nerve block was given via extraoral approach with 5 ml of 0.5% bupivacaine using peripheral nerve stimulator to determine the difference in Pre block and Post block mouth opening and the VAS score at 2, 5, 10, 15, 20, 25, and 30 minutes. RESULTS: The Interincisor distance measured Pre block was 1.20 ± 0.32 mm and was significantly increased after 5 mins onwards from the block (P < 0.005). The VAS score determined Pre block was 5.14 ± 1.37 which significantly decreased just 2 minutes after the application of block (P < 0.005). CONCLUSION: Mandibular nerve block decreases the pain and will aid in the decision making by an anesthetist regarding airway management as it helps in increasing the inter incisor distance significantly. Moreover, given the feasibility and effectiveness of the block it could be included in standard of care protocol for mandibular fracture patients.