Anatomical variation in the cervical branch of the facial nerve: a systematic review

There is a paucity of literature on the anatomical variations of the cervical branch of the facial nerve (CBFN). Poor awareness of its anatomy and variations risks intraoperative damage, misdiagnosis of facial nerve injury and undesirable functional and aesthetic outcomes for patients.

To review anatomical studies on the CBFN and synthesise data on its course, innervations and common variations.

A PRISMA-compliant systematic review of anatomical studies of the cervical branch of the facial nerve was conducted. PubMed, Embase, Scopus, Cochrane Library, Web of Science, and Google Scholar were searched up to July 2025. Papers were quality appraised, and data relevant to the anatomy of the CBFN were extracted.

Thirty-five papers with a collated sample size of 867 hemi-necks were identified: 25 with anatomical dissections and 10 case reports. The mean number of CBFN branches was 1.34 (sensitivity range 1.31-1.36). Communication with the marginal mandibular nerve, transverse cervical nerve and great auricular nerve was variable, with prevalences ranging from 22-97%. Distances between the nerve and anatomical landmarks were heterogeneous. Many individual cases of cervical branch variation in course and relationship to nearby vasculature were identified.

The cervical branch of the facial nerve displays wide variability in its course. Pre-operative mapping, careful dissection and intra-operative nerve stimulation to aid accurate identification are recommended to prevent iatrogenic damage.