Numerous muscles inserts into the orbicularis oris inferior and superior muscles, providing a flexible system for lips protrusion, closure, retraction, elevation, and depression.
Numerous muscles inserts into the orbicularis oris inferior and superior muscles, providing a flexible system for lips protrusion, closure, retraction, elevation, and depression.
轮颊肌为嘴唇上下方的肌肉，能让嘴唇的开合及前后伸缩自如。