We learned that the muscles for the upper lip are the levator muscles.
There are three muscles in your face on the front of your chin that help push up your bottom lip:
depressor anguli oris, depressor labii inferioris, mentalis.
(from: wikipedia - depressor anguli oris)
(from: wikipedia - depressor labii inferioris)
(from: wikipedia - mentalis)
Kid Facts - Blast from the past: Distal Phalanges