What does the orbicularis oris muscle primarily control?

The orbicularis oris muscle primarily controls the movement of the lips. This circular muscle encircles the mouth and is crucial for various functions, including articulating speech sounds, sealing the lips during swallowing, and facilitating facial expressions related to emotions. Its contraction allows for actions such as puckering, biting, and forcing air out during speech or singing.

While other muscles are responsible for movement in the cheeks, jaw opening, and broader facial expressions, the orbicularis oris is specifically designated for lip movement. Understanding the precise function of this muscle is essential for speech language pathologists, as issues with the orbicularis oris can directly affect communication and oral motor skills.