This case report presents an impacted third molar with associated dentigerous cyst in which the IAN is externalised and runs along the lateral surface of the mandible. This case reiterates the limitations of standard radiographic techniques such as the orthopantomogram.

Third molar surgery remains one of the commonest procedures carried out by oral surgeons. One of the main concerns whilst performing this procedure is inferior alveolar nerve (IAN) damage. We present a case of an unusual anatomical variation in which the inferior alveolar nerve was externalized. This case reiterates the need for appropriate pre-operative radiological assessment to identify the anatomic relationship of IAN with third molar teeth. In this occasion, an altered approach was required to preserve the IAN. This report is in line with the SCARE criteria.