Posterior Auricular Artery as a Landmark to the Facial Nerve During Parotidectomy: A Cadaver Study

OBJECTIVE: To investigate the anatomical relationship between the posterior auricular artery and the main trunk of the facial nerve for utilizing the posterior auricular artery as a landmark for the facial nerve during parotidectomy. METHODS: A total of 10 fresh cadaveric heads (20 sides) underwent dissection of the parotid region. The main trunk of the facial nerve, posterior auricular artery, stylomastoid artery, and occipital artery was identified. The origin, course, and branching patterns of the posterior auricular artery and its anatomical relationship with the facial nerve trunk were analyzed. Relevant anatomical measurements were recorded. RESULTS: In 20 sides, the posterior auricular artery originated from the external carotid artery in 19 cases and from the occipital artery in 1 case. The postauricular artery ran laterally to the facial nerve in 15 cases, medially to the facial nerve in 3 cases, and penetrated the facial nerve in 2 cases. The diameter of the posterior auricular artery was 1.45 ± 0.25 mm at its origin, and 1.13 ± 0.20 mm at the point where it crossed the facial nerve. The stylomastoid artery originated from the posterior auricular artery in 17 cases and from the occipital artery in 3 cases. The average diameter of the stylomastoid artery was 0.85 ± 0.22 mm. The stylomastoid artery ran medially to the facial nerve in 16 cases (80%), laterally in 4 cases (20%). CONCLUSION: The posterior auricular artery can serve as a reliable anatomical landmark for identifying the main trunk of the facial nerve during parotid surgery. LEVEL OF EVIDENCE: N/A.