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

The main methods of facial nerve trunk localisation can be divided into antegrade and retrograde. The former utilises anatomical landmarks to identify the nerve trunk after its exit from the stylomastoid foramen, which is then traced distally.Landmarks commonly used are:The inferior poion of the cailaginous canal. This is termed Conley's pointer (tragal pointer) and indicates the position of the facial nerve, which lies 1 cm deep and inferior to its tip;The upper border of the posterior belly of the digastric muscle. Identification of this muscle not only helps to mobilise the parotid gland, but also exposes an area immediately superior, in which the facial nerve is usually located;The squamotympanic fissure;The styloid process (the nerve is superficial to it);The mastoid process can be drilled and the nerve identified more proximally.Retrograde techniques rely on the identification of one of the nerve main branches (buccal in relation to the parotid duct, marginal mandibular in relation to the facial vessels, temporal branch), which is then traced proximally until the main trunk is identified.Ref: Bailey and love, page no: 790