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