Muscles of Face/Lips
Depressor anguli oris
O: lateral margins of mandible on oblique line C: vertically upward I: angle of mouth, corner of upper lip In: VII F: depresses corner of mouth, compress upper lip against lower lip
Masseter
O: Zygomatic arch C: down I: Ramus of manible In: V-not facial nerve F: elevates mandible, closes mouth
Levator anguli oris
O: canine fossa of maxilla C: vertically down I: corners of upper & lower lip In: VII Facial nerve F: draws corner of mouth up and medially
Zygomatic minor
O: facial surface of zygomatic bone C: downward and medially I: mid-lateral lip, OO In: VII Facial nerve F: Elevation of upper lip
Platysma
O: fascia overlaying pectoralis major and deltoid (shoulder muscle) C: up I: corner of mouth, lower margin of mandible In: VII F: depression of mandible
Mandibular depressors
When the hyoid is in a fixated position, these contract to depress: - Diagastricus- depress mandible -Mylohyoid- depresses mandible -Geniohyoid- depresses mandible -Platysma- depresses mandible
Anterior and Posterior Belly of Digastricus
Anterior Belly O: inner surface of mandible C: medial and down I: junction of corpus and greater cornu of hyoid In: V F: depress mandible Posterior Belly O: Mastoid process, temporal bone C: medially and down I: juncture of corpus and greater cornu of hyoid In: VII F: depress mandible
What muscles :
Cause you to smile? -Levator Anguli Oris -Zygomatic Major Create a snarling face? -Levator Labii Alaeque Nasi Superioris Create a pout? - Depressor Labii Inferior - Mentalis Create a frown? - Depressor anguli oris
Muscles moving the upper lip
Compress lips, assist in elevating upper lip -Levator anguli oris -Levator Labii Superioris -Levator Labii Alaeque Nasi Superioris -Zygomatic Minor -Zygomatic Major
Buccinator- Transverese Facial Muscles
Deep to Risorius(under) Principle muscle of cheek Moves food onto grinding surfaces of teeth- critical muscle for chewing
Muscles that move the lower lip
Depressor Labii Inferior Mentalis Depressor anguli oris
What muscles open the jaw or depress mandible?
Digastricus Geniohyoid Mylohyoid Platysma
What muscle protrudes the jaw?
Lateral external pterygoid muscle
Orbicularis Oris
O: Corner of lips C: laterally I: opposite corner of lip In: VII Facial nerve F: constrict and purse lips, all the other muscles attach to the Orbicularis oris
Levator Labii Alaeque Nasi Superioris
O: Frontal process of maxilla C: vertically along margin of nose I: mid-lateral region of upper lip In: VII Facial nerve F: elevate upper lip, snarling muscle, "Elvis muscle"
Risorius
O: fascia of Masseter muscle C: horizontally forward I: OO corner of mouth In: VII Facial nerve F: retracts corners of mouth, expression, smiling, grinning, primarily expression
Medial (internal) pterygoid muscle
O: lateral pterygoid plate and fossa of sphenoid bone C: down and back I: medial side of ramus of mandible In: V F: elevates mandible
Mandibular Movement: Musculature
Elevation(closing) -Masseter -Temporalis -Internal(medial) pterygoid muscle Protrusion(opening) -External(lateral) pterygoid muscle Depression -Platysma -Geniohyoid -Mylohyoid -Digastricus last 3 main jaw opening muscles
Lips=Function
Fibers of several muscles insert into Orbicularis Oris muscle- extent of lip movement is a result of the combination of all these forces Upper lip movement is rather limited in most speakers Lower lip physically connected to other movable articulator(mandible)- upper and lower lip show different movement characteristics
What muscles raise the jaw?
Masseter Temporalis Medial internal pterygoid
Lateral (External) Pterygoid muscle
O: lateral pterygoid plate and greater wing of sphenoid C: back I: mandible In: V F: protrudes, depresses mandible, grinding action of molars Antagonist to elevators in grinding action of molars
Zygomatic major
O: lateral to zygomatic minor on zygomatic bone C: down and medially I: Corner of OO In: VII Facial nerve F: elevates and retracts corners of mouth
Mentalis
O: mandible near incisive foramen(just below incisors) C: vertically downward I: skin of chin below In: VII F: elevates and wrinkles chin, pulls lower lip out
Levator Labii Superioris
O: maxilla C: down and medially I: OO, upper lip In: VII Facial nerve F: elevates upper lip
Geniohyoid
O: mental spines of mandible C: medially I: Corpus of hyoid In: XII hypoglossal
Mylohyoid
O: mylohyoid line9inner mandible, inferior to geniohyoid) C: back and down I: Median fibrous raphe inferior hyoid In: V
Depressor Labii Inferior
O: oblique line of mandible, near mental foramen C: up and medially I: corner of lower lip In: VII F: depresses lower lip, pulls lip down and out
Buccinator
O: pterygomandibular ligament9ligament connecting sphenoid and mandible) C: horizontally forward I: OO at corners In: VII Facial nerve F: retracts lips, compresses lips & cheeks against teeth, constricts oral cavity, primarily chewing
Temporalis
O: temporal fossa of temporal & parietal bones C: down, through zygomatic arch I: Coronoid process and ramus of mandible In: V F: closes mouth, retract jaw
Overview of Muscles of Face/Lips
Orbicularis oris- pull lips together like a drawstring -Main muscle of the lips Transverse muscles=retract lips, course horizontally, insert into Orbicularis oris, pull lips against teeth, compress lips -Buccinator -Risorius Vertical muscles- enter Orbicularis oris from above or below, facial expression, compress corners of mouth -Mentalis -Depressor Anguli Oris -Levator Anguli Oris Angular muscles- approach Orbicularis oris from angle, smiling and frowning -Levator Labii Superior -Levator Labii SUperior Alaeque Nasi -Zygomatic major -Zygomatic minor -Depressor Labii Inferior Platysma