The buccinator is a muscle in the cheek which joins the cheekbone and jawbone to the mouth, where it blends with the muscle of the upper and lower lips. A duct, or tube, leading from the parotid salivary gland runs through the buccinator muscle before opening into the mouth. The buccinator helps keep food in position between the teeth while chewing, and gives stiffness to the cheeks which prevents them from being bitten. It is also involved in smiling and blowing, the action from which it gets its name, as the word buccinator, or bucinator, means trumpeter in Latin.
If one blows through pursed lips so that the cheek muscle becomes puffed out, it is possible to feel the buccinator muscle with the fingers. As the face is symmetrical, there are two buccinators, one on each side. The buccinator is one of the muscles of mastication, so it is important in the process of eating, where it acts to press the cheeks and lips inward against the teeth. Working against the action of the tongue, which moves food out toward the cheeks, the buccinators tend to push food into place between the upper and lower sets of teeth, where it can be ground up by chewing.
The buccinator muscle receives its nerve supply from a branch of the facial nerve, which can be damaged in a condition known as Bell's palsy. In Bell's palsy, inflammation of the facial nerve prevents it from functioning, causing weakness of those facial muscles normally supplied by the nerve. Involvement of one of the buccinators can make it difficult to eat properly, with food escaping from the mouth or becoming trapped between the teeth and the cheek. The mouth might be seen to droop at one end and smiling may only be one-sided. Although it can appear worrying and may be confused with a stroke, most cases of Bell's palsy will actually get better without treatment.
Musicians who play wind instruments rely on using the buccinators to produce the right sound, especially in the case of brass players. What is known as the embouchure, or the way in which the tongue and lips are held to the mouthpiece to produce musical notes, depends largely upon the relative tensions between the buccinators and the lip muscles. The famous jazz trumpeter Dizzy Gillespie appeared to have stretched his buccinator muscles to such an extent that his cheeks became hugely distended while playing. A useful function of the buccinators for musicians is that the muscle fibers surround the duct that leads from the parotid salivary gland. They function as a valve when blowing, preventing air from inflating the duct.