Dentaltown - Ben Kenobi: Did Obi-Wan Kenobi have an oral sphincter? Obi-Wan. Now there's a name I've not heard in a long, long time. A long time. Luke Skywalker: Do you know the oral sphincter? Ben Kenobi: Of course I know him...he's not a sphincter, he's the orbicularis oris muscle, a complex muscle consisting of fibers that completely encircle the mouth. Its function is apparent when pursing the lips, as occurs during whistling. Some of its fibers originate near the midline from the maxilla s