The site of the facial nerve most vulnerable to injury during parotidectomy is at:

• A The stylomastoid foramen at the exit of the mastoid
• B The marginal mandibular branch as it crosses the inferior border of the mandible ✓
• C The main trunk before its bifurcation into temporofacial and cervicofacial divisions
• D The zygomatic branch in the malar region

Explanation

The marginal mandibular branch of the facial nerve is the most commonly injured branch during parotidectomy and submandibular gland surgery. It has a variable course near the inferior border of the mandible and the angle of the mouth, with limited arborisation and cross-innervation compared to other branches. Injury results in lower lip weakness. The main trunk is identified behind the parotid, and the bifurcation point is used as a landmark — damage here would affect all branches but is less likely with careful dissection.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.