A case report of the abnormal branching pattern of the facial nerve and its relationship to the posterior auricular artery

Abstract Variation of the facial nerve accompanying with vascular variation was encountered on the left side of a male cadaver during the routine dissection. Facial nerve gave off five main branches instead of typically bifurcated pattern. On the other hand its trunk was pierced by the posterior auricular artery. In the present case, a unique branching pattern of the facial nerve and its variative relationship with posterior auricular artery were discussed regarding clinical aspects and embryological development. We suggest that the artery piercing the nerve trunk significantly increases the risk of iatrogenic injury of facial nerve. Different branching patterns and anastomoses may result in unexpected functional consequences of mimetic muscles after damage of nerve branches. Therefore, awareness of the variations of the facial nerve and its branches are clinically important to decrease relevant complications.