Buccal Branch of the Facial Nerve: Cheek Anatomy
- Nerve
Quick facts
- Origin
- Branches of the facial nerve that leave the anterior border of the parotid gland, usually more than one.
- Course
- They cross the cheek almost horizontally, over the masseter, above and below the parotid duct.
- Muscles
- Buccinator, orbicularis oris, upper lip elevators, zygomaticus muscles, risorius and the muscles of the nose.
- Distinctive feature
- They have many connections with the zygomatic branch, which gives the innervation redundancy.
- Relevance in orofacial harmonization (HOF)
- Relationship with buccal fat removal, midface threads and the parotid duct.
The buccal branch of the facial nerve is really a group of branches that leaves the anterior border of the parotid gland and crosses the cheek almost horizontally to the muscles of the upper lip, the nose and the cheek itself. It controls the buccinator, the orbicularis oris, the upper lip elevators and part of the zygomaticus muscles. It runs alongside the parotid duct, over the masseter, which makes it a landmark in the anatomy of the lateral middle and lower face.
What is the course of the buccal branch?
| Segment | What to look for |
|---|---|
| Exit | Anterior border of the parotid, usually as two or more branches |
| Over the masseter | Runs beneath the SMAS, over the masseter fascia, above and below the parotid duct |
| Anterior border of the masseter | Passes outside the buccal fat pad and reaches the buccinator region |
| Reaching the muscles | Enters the muscles of expression through their deep surface, near the nasolabial fold and the lip |
The pattern of the branches varies a lot between people and between sides. Connections with the zygomatic branch are frequent, so the two are sometimes described together as a midface plexus.
How does it relate to the parotid duct?
The parotid duct carries saliva from the parotid to the mouth. It crosses the masseter roughly at the middle third of a line drawn from the tragus to the midpoint between the nasal ala and the vermilion of the upper lip, then pierces the buccinator to open onto the mucosa at the level of the upper second molar. Buccal branches usually follow this course, above and below the duct. The transverse facial artery also runs through the region, slightly higher.
Why does it matter in orofacial harmonization (HOF)?
- Buccal fat removal: the intraoral approach to the buccal fat pad passes close to the buccal branches and the duct. Injury is uncommon, but it is a described complication. See buccal fat removal: when it is indicated.
- Midface threads: thread lifts cross the cheek, and the plane chosen is an anatomical decision.
- Reading the smile: weakness of a buccal branch changes the elevation of the upper lip and can be mistaken for a toxin effect or natural asymmetry.
- Toxin in the masseter: the toxin acts on the muscle, not on the nerve, but diffusion to neighboring muscles such as the risorius and the zygomaticus can change the smile. The topic is covered in botulinum toxin in the masseter.
How does it show up in the assessment?
- Function before the procedure: ask the person to smile, show their teeth, puff out the cheek and whistle, comparing the sides.
- History: previous facial palsy, parotid or facial surgery and buccal fat removal.
- Documentation: photos and a short video of the smile and speech help separate a prior asymmetry from a new effect.
Also called: buccal branches of the facial nerve, ramus buccalis, buccinator branch of the facial nerve (old usage). Not to be confused with the buccal nerve, which is sensory and comes from the trigeminal nerve.
Frequently asked questions
What happens if the buccal branch of the facial nerve is injured?
There may be weakness in the upper lip and cheek, with difficulty smiling symmetrically, whistling or keeping food out of the vestibule. Because the buccal branches communicate heavily with the zygomatic branch, partial or full recovery is common, but it depends on the type of injury.
Where does the parotid duct run in relation to the buccal branch?
The parotid duct crosses the masseter roughly at the middle third of a line between the tragus and the midpoint between the nasal ala and the upper lip. The buccal branches usually run alongside it, above and below.