From the Guidelines
The facial nerve can be located on the surface of the face by following specific anatomical landmarks, with the main trunk exiting the skull through the stylomastoid foramen, approximated by a point just anterior to the mastoid process, behind the ear lobe, as described in the most recent study 1. The surface markings of the facial nerve are crucial for surgeons to understand in order to avoid injury during procedures in the face and neck region.
- The main trunk of the facial nerve exits the skull through the stylomastoid foramen, which can be approximated by a point located just anterior to the mastoid process, behind the ear lobe.
- From this point, the nerve travels anteriorly through the parotid gland, where it divides into its five major branches.
- These branches can be traced using a line drawn from the lobule of the ear to a point midway between the angle of the mandible and the tip of the mastoid process.
- The temporal branch runs upward across the zygomatic arch, the zygomatic branch crosses the zygomatic bone, the buccal branch traverses the cheek parallel to the parotid duct, the marginal mandibular branch follows the lower border of the mandible, and the cervical branch descends into the neck. The facial nerve is particularly vulnerable where it emerges from the stylomastoid foramen and within the substance of the parotid gland, as damage can result in facial muscle paralysis, highlighting the importance of accurate surface markings, as noted in 1. Understanding these surface markings is essential for minimizing the risk of facial nerve injury and its associated morbidity, mortality, and impact on quality of life, especially in the context of surgical procedures in the face and neck region, as emphasized by the most recent and highest quality study 1.