Post-traumatic trigeminal neuropathy following third molar extraction due to retromolar canal injury: a case report

The inferior alveolar nerve block (IANB) is the most frequently used mandibular nerve block in oral surgery; however, it has a reported failure rate of 15%-45%. The presence of the retromolar canal (RMC) and nerve, an anatomical variation in the mandibular retromolar region, can cause IANB failure. Although its occurrence is variable, the canal has gained increasing clinical relevance because of its vulnerability during oral and maxillofacial surgical procedures. Its presence may result in anesthetic failure during IANB and, less commonly, may act as a conduit for spreading infection or tumor metastasis. Although several studies have examined the prevalence and anatomical variations of the RMC, literature specifically addressing the traumatic neuropathy from injury to this area during third-molar extraction is lacking. This case report details post-traumatic trigeminal neuropathy following injury to the RMC during third-molar extraction. The case findings contribute to the limited clinical evidence, emphasize the importance of preoperative identification of anatomical variations, and underscore the need for meticulous intraoperative management to minimize the risk of iatrogenic neuropathic complications.