Buccinator is one of the muscles of the cheeks and lips. On each side, it has a complex origin from:
- maxilla: along the alveolar process superior to alveolar margin horizontally
between the anterior border of the the first to the posterior border of the
third molars before turning inferiorly to extend to the maxillary tubercle
- mandible: along the oblique line of the mandible between the first and third molars
- pterygomaxillary ligament
- pterygomandibular raphe posteriorly
Its muscle fibres pass anteriorly to converge on the orbicularis oris muscle
in the modiolus of the mouth. Fibres originating from the ligament and raphe
decussate at the modiolus whereas those originating from bone pass directly
into the nearest lip without crossing.
Superficial to buccinator is the buccal fat pad. Deep to the muscle is the mucous membrane of the cheek. It is traversed by the parotid duct.
Its arterial supply is from the buccal artery.
It is not a primary muscle of mastication - it does not move the jaw - and
this is reflected in its motor innervation from the facial nerve. However, proprioceptive
fibres are derived from the buccal branch of the mandibular part of the trigeminal
nerve (CN V).
The actions of buccinator are to:
- move boluses of food out of the vestibule of the mouth and back towards the molar teeth
- tense the cheeks during blowing and whistling
- assist with closure of the mouth