The buccinator muscle, a thin and quadrilateral facial muscle, forms a significant part of the cheek. It plays a broad role in various everyday oral activities, contributing to both essential physiological processes and intricate actions. This muscle is fundamental for the movement and stability of the cheek, impacting several aspects of daily function.
Core Functions
The buccinator muscle performs several actions that are central to oral function. During chewing, it compresses the cheeks firmly against the molar teeth, which helps to keep food positioned between the biting surfaces. This action prevents food from escaping into the oral vestibule, the space between the teeth and the cheek, and also helps prevent accidental biting of the cheek. The muscle also assists the tongue in maintaining the food bolus centrally within the oral cavity during mastication.
Beyond chewing, the buccinator is crucial for actions that involve air pressure within the mouth. It expels air from distended cheeks, a function that is essential for blowing activities such as playing wind instruments like a trumpet, or whistling. This muscle is also activated during sucking, a fundamental action for infants during nursing and for adults drinking through a straw.
Anatomical Position and Connections
The buccinator muscle is located within the cheek, positioned between the upper jaw (maxilla) and the lower jaw (mandible). It acts as the primary muscular wall of the cheek, providing its structure and tightness. The muscle originates from the alveolar processes of both the maxilla and mandible, specifically near the molar teeth, and also from the pterygomandibular raphe, a fibrous band in the back of the mouth.
Its fibers converge toward the corner of the mouth, where they interlace with other muscles, forming a dense fibromuscular mass called the modiolus. From the modiolus, buccinator fibers blend into the orbicularis oris muscle, which encircles the mouth, and extend into the upper and lower lips. The buccinator receives its motor signals from the buccal branch of the facial nerve, also known as Cranial Nerve VII.
Significance in Daily Life
The buccinator muscle’s functions are deeply integrated into many routine activities. This muscle is considered an accessory muscle of mastication, working in coordination with stronger jaw muscles. Without proper buccinator function, food can accumulate in the oral vestibule, making chewing difficult.
The buccinator also contributes to clear speech articulation, influencing how certain sounds are formed. In infants, the buccinator is one of the first muscles to become active, playing a role in the suckling reflex. Furthermore, this muscle helps maintain the overall tension of the cheeks, which can assist in stabilizing dental prosthetics.