Anatomic landmarks for masseteric nerve identification: Anatomic study for a new reference point

The masseteric nerve is often used as a donor nerve in the treatment of facial paralysis. Even if several anatomical studies described landmarks for its identification, their main disadvantages are the anatomical variability and the changes due to surgery. Sixteen dissections were performed on cadaveric specimens. The masseteric muscle (MM), the zygomatic arch (ZA), the masseteric nerve (MN) and the zygomatic branch of the facial nerve (ZB) were identified and their relationships were measured. The relationships between MN and ZB resulted to be constant, with MN intersecting ZB at a depth of 0,78 cm in the muscle, 1,6 cm below ZA and 0,8 cm from the posterior border of MM. The measures obtained demonstrated as the main zygomatic branch of the facial nerve can be a suitable landmark for the identification of the masseteric nerve, with no variations due to the surgical procedure or patient characteristics.