Iatrogenic traumatic facial nerve palsy is MOST commonly produced during which of the following surgical procedure?

Iatrogenic facial nerve trauma most often occurs during mastoidectomy. When injury occur to more than 50% of the neural diameter either primary reanastomosis or reconstruction using a nerve graft is done. Complications of mastoidectomy includes: Infection Labrynthitis ossificans Mucosalization of the middle ear Facial nerve injury CSF leak Encephalocele