Identifying the Facial Nerve in Parotid Surgeries: How We Do It

The facial nerve is an important structure related to parotid gland surgery. Its identification at the time of surgery is critical. Multiple anatomical landmarks have been described to aid in its identification. The objective of this study is to assess whether the tympanomastoid suture is a better surgical landmark than the tragal pointer for identifying the facial nerve while performing parotidectomy.

Sixty patients presenting over a period of 3 years from 2016 to 2018 with a parotid swelling without pre-operative facial weakness were included in the study. The average distances between the facial nerve (FN) and the tragal pointer (TP), and the facial nerve (FN) and tympanomastoid suture (TMS) were calculated intra-operatively and compared.

Out of the 60 patients operated, 54 underwent superficial parotidectomy and 6 underwent total conservative parotidectomy. The mean distance between the FN (main trunk) and TP was found to be 18.38 ± 6.85 mm and that between FN and TMS was found to be 2.92 ± 0.6 mm (P<0.0001).

Tympanomastoid suture is a fairly constant and consistent bony landmark to locate the facial nerve during parotid surgeries as compared to the more commonly used cartilaginous tragal pointer. The results of this study can guide surgeons during parotidectomy, to correctly and promptly identify the facial nerve thereby reducing the risk of injury.