buccinator muscle (anatomy)

Last reviewed 01/2018

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.

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