Overview
The cervical branch of the facial nerve supplies the platysma and helps move the lower face. It can be injured during neck dissection and rhytidectomy. The authors searched PubMed, Web of Science, SCOPUS and ScienceDirect under PRISMA rules; of 402 records screened, 10 anatomical or cadaver studies met criteria.
Findings
- 402 records screened; 10 studies included.
- Single trunk in 61.3% to 80% of specimens; double branches in 20% to 38.7%.
- Connections with the transverse cervical nerve: 16% to 100%.
- Connections with the great auricular nerve: 24% to 38.7%.
- Connections with the marginal mandibular nerve: 24%.
- The branch ran deep to the platysma in all cases and below the jaw.
- Its relation to the cervical fascia and submandibular gland varied.
- Injury may affect the marginal mandibular branch through these connections, causing lower lip weakness.
- Level of evidence: 5.
What it means for a patient
- The nerve branch to the neck muscle runs under the platysma, so dissection there during face and neck surgery puts it at risk.
- Because it connects with the nerve to the lower lip, injury can weaken the lower lip.
- Careful dissection under the platysma is needed to protect it.
- Limits: 10 anatomical studies with wide ranges, no patient outcome data, and bias judged by a qualitative tool.
Why this paper matters
It gathers the anatomy of the cervical branch and its connections, and explains how injury to it may cause lower lip weakness. The authors call for caution during dissection beneath the platysma.
Terms
- Cervical branch of the facial nerve: the facial nerve branch that supplies the platysma.
- Platysma: the thin muscle sheet of the neck.
- Marginal mandibular branch: the facial nerve branch to the lower lip muscles.
- Anastomosis: a connection between two nerves.
- Great auricular nerve: a sensory nerve to the ear and nearby skin.
- Paresis: partial weakness of a muscle.
- Subplatysmal dissection: surgery beneath the platysma.
- Iatrogenic injury: harm caused by medical treatment.