Which of the following is not a landmark for facial nerve during parotid surgery ?

Facial nerve paralysis is a daunting potential complication of parotid surgery. Knowledge of the key landmarks of the facial nerve trunk is essential for safe and effective surgical intervention in the region of the parotid gland. In current practice, wide ranges of landmarks are used to identify the facial nerve trunk, however, there is much debate in the literature about the safety and reliability of each of these landmarks Major surgical landmarks to the facial nerve include the tympanomastoid suture line, the tragal pointer, the posterior belly of the digastric muscle. the retromandibular vein, and the styloid process of the temporal bone. The tympanomastoid fissure- The most used anatomical landmark is the tympanomastoid fissure. The tympanomastoid fissure lies between the mastoid and tympanic segments of the temporal bone. The facial nerve lies approximately 6-8 mm medial to suture. The Tragal pointer the nerve is usually located inferior and medial to the Tragal pointer of the external auditory canal, about 10mm. The Digastric muscle The facial nerve lies just superior and on the same plane as the plane of digastric muscle attachment. If the main trunk of facial nerve cannot be readily identified, retrograde dissection of a branch of facial nerve can be used. The buccal branch is best for this approach. In the infant and young child, these landmarks are not applicable because of differences in the rate of anatomic development of the parotid gland and mastoid.