Muscles of The Lips Locations and Functions

Orbicularis oris (function)

Contraction can move the lips toward each other and forward (to closure), move the corners of the mouth in several directions, an force the lips and/or corners of the mouth against the teeth

Buccinator (function)

Contraction can pull the mouth corner backward and toward the side and can force the lip and cheek against the teeth

Risorius (function)

Contraction draws the corner of the mouth backward and toward the side

Levator anguli oris (caninus) (function)

Contraction draws the corner of the mouth upward and toward the side and may raise the lower lip against the upper lip

Levator labii superioris (function)

Contraction elevates the upper lip

Zygomatic minor (function)

Contraction elevates the upper lip and pulls the corner of the mouth upward

levator labii superioris alaeque nasi (function)

Contraction of the lip segment elevates the upper lip (recall that the nasal segment dilates the anterior naris)

Zygomatic major (function)

Contraction pulls backward on the corner of the mouth and lifts it upward and toward the side

Mentalis (function)

Contraction pulls chin tissue upward, forces lower part of lower lip against alveolar process of the mandible, and curls the lower lip outward; called pouting muscles

incisivus labii inferioris (function)

Contraction pulls downward and inward on the corner of the mouth

Depressor anguli oris (triangularis) (function)

Contraction pulls the corner of the mouth downward and draws the upper lip downward and toward the lower lip

Incisivus labii superioris (function)

Contraction pulls the corner of the mouth upward and toward the midline

Depressor labii inferioris (location)

Contraction pulls the lower lip downward and toward the side and may also cause the lower lip to turn outward

Platysma

Originates from a sheet of connective tissue within the neck above the clavicle (and may extend from farther below) and inserts on lower edge of the mandible and some fibers blend with muscles of the lower lip and corner of the mouth

Levator labii superioris (location)

Originates from below the orbit of the eye, the front of the maxillary bone, and the zygomatic bone and inserts into the upper lip

Risorius (location)

Originates from fascia of the master muscle and inserts into the corner of the mouth and lower lip

Levator anguli oris (caninus) (location)

Originates from the front of the maxilla and inserts on both the upper and lower lips near the corner of the mouth

Zygomatic minor (location)

Originates from the inner surface of the zygomatic bone and inserts into the upper lip

incisivus labii inferioris (location)

Originates from the mandible near the lateral incisor tooth and inserts in the corner of the mouth

Incisivus labii superioris (location)

Originates from the maxilla near the canine tooth and inserts into the corner of the mouth

Depressor anguli oris (triangularis) (location)

Originates from the outer surface of the mandible and inserts on the orbiculares oris muscle at the corner of the mouth and into the upper lip

Buccinator (location)

Originates from the pterygomandibular ligament, the outer surface of the alveolar process of the maxilla, and the mandible near the last molars and inserts into the upper and lower lips near the corner of the mouth

Zygomatic major (location)

Originates from the side of the zygomatic bone and inserts into the corner of the mouth

Orbicularis oris (location)

The only muscle of the lips that contains intrinsic fibers. Forms a ring of muscle within the upper and lower lips

Mentalis (location)

originates from the front and side of the mandible near the midline and insets into the orbicularis iris muscle and skin overlying the chin

levator labii superioris alaeque nasi (location)

originates from the front of the maxilla and the lip segment inserts in the upper lip