The buccinator is a thin, flat muscle located in the cheek region of the face. It extends from the pterygomandibular raphe (a fibrous band that runs between the pterygoid muscles) to the corner of the mouth. The buccinator muscle is responsible for compressing the cheeks and helping to keep the food in contact with the teeth during chewing, which aids in the process of mastication (chewing). It also helps to blow air out of the mouth, such as when playing a musical instrument or blowing up a balloon. The buccinator muscle is innervated by the facial nerve (cranial nerve VII) and works in conjunction with other facial muscles to produce a range of facial expressions. Dysfunction or weakness of the buccinator muscle can lead to difficulties with chewing, speech, and facial expressions.