Omohyoid Muscle Trapezius Muscle Masseter Muscle Orbicularis Oris Muscle Mentalis Muscle Depressor Labii Inferioris Muscle Depressor Anguli Oris Muscle Buccinator Muscle Zygomaticus Major Muscle Zygomaticus Minor Muscle Levator Labii Superioris Muscle Temporal Muscle Orbicularis Oculi Muscle Sternocleidomastoid Muscle Frontalis Muscle
Orbicularis Oculi Muscle
The uppermost and lowermost of the Buccinator muscle pass across the lips from side to side without decussation. Superficial to this stratum is a second which is formed on either side by the caninus and the Triangularis, which cross each other at the angle of the mouth; those fibers from the Caninus passing to the lower lip and those of the Triangularis passing to the upper lip, along which they run to be inserted into the skin near the median line.
There are other transverse fibers that intermingle with these and their direction is mostly oblique. They are fibers from the Quadratus labii superioris , the Zygomaticus, and the Quadratus labii inferioris. The proper fibers of the lips are oblique (sloping or joining something at an angle that is not a right angle).
The origin of the Orbicularis Oris is the Maxilla and Mandible with the insertion being the lips. Finally, there are fibers connecting the Orbicularis Oris muscle to the Maxilla and the septum of the nose above and with the Mandible below. The interval between the two medial bands seen on the lip beneath the the nose is a depression called the philtrum. It is sometimes known as the “kissing“ muscle because it is used to pucker the lips.