Head 2

Muscles of Facial Expression
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Lie in the subcutaneous tissue of the face.
All innervated by the terminal motor branches of the facial nerve (CN VII)
Take origin from the underlying facial skeleton, but insert into the skin or facial cartilages

Muscles of Facial Expression
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Can be divided by region:
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Scalp
Nose
Mouth
Eye
Neck

Scalp
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Epicranius
Composed of an epicranial aponeurosis and the occipitofrontalis muscle
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Frontal belly of occipitofrontalis 
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O: Frontal bone
I: Epicranial aponeurosis
Moves scalp, eyebrows; wrinkles skin of forehead

Occipital belly of occipitofrontalis 
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O: Superior nuchal line
I: Epicranial aponeurosis
Retracts scalp

Nose
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Nasalis
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O: Maxillae and alar cartilage of nose
I: Dorsum of nose
Compresses bridge and depresses tip of nose; elevates corners of nostrils Procerus
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O: Nasal bone and lateral nasal cartilage
I: Aponeurosis at bridge of nose and skin of forehead Moves and wrinkles nose

Mouth
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Buccinator
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Compresses cheek; holds food between teeth during chewing
O: Alveolar processes of mandible and maxillae
I: Orbicularis oris

Depressor anguli oris
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Draws corners of mouth inferiorly and laterally
(“frown” muscle)
O: Body of mandible
I: Skin at inferior corner
(angle) of mouth

Mouth
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Depressor labii inferioris 
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Draws lower lip inferiorly O: Body of mandible lateral to midline
I: Skin at inferior lip

Levator anguli oris
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Draws corners of mouth superiorly and laterally (“smile” muscle) O: Lateral maxilla
I: Skin at superior corner of mouth

Mouth
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Levator labii superioris 

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Opens lips; raises and furrows the upper lip
(“Elvis” lip snarl)
O: Zygomatic bone; maxilla I: Skin and muscle of superior lip

Mentalis
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Protrudes lower lip
(“pout”); wrinkles chin
O: Central mandible
I: Skin of chin

Mouth
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Orbicularis oris
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Compresses and purses lips (“kiss” muscle)
O: Maxilla and mandible; blend with fibers from other facial muscles
I: Encircling mouth; skin and muscles at angles to mouth Risorius
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Draws corner of lip laterally; tenses lips; synergist of zygomaticus
O: Deep fascia associated with masseter muscle
I: Skin at angle of mouth Mouth
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Zygomaticus major
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Elevates corner of the mouth (“smile” muscle) O: Zygomatic bone
I: Skin at superolateral edge of mouth Zygomaticus minor
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Elevates corner of the mouth (“smile” muscle) O: Zygomatic bone
I: Skin of superior lip Eye
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Corrugator supercilii
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Pulls eyebrows inferiorly and medially; creates vertical wrinkles above nose O: Medial end of superciliary arch
I: Skin superior to supraorbital margin and superciliary arch

Levator palpebrae superioris 
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Elevates superior eyelid
O: Lesser wing of sphenoid bone
I: Superior tarsal plate and skin ofsuperior eyelid

Eye
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Orbicularis oculi
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Closes eye; produces winking, blinking, squinting
(“blink” muscle)
O: Medial wall or margin of orbit
I: Skin surrounding eyelids Neck
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Platysma
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Pulls lower lip inferiorly; tenses skin of neck
O: Fascia of deltoid and pectoralis major muscles and acromion of scapula
I: Skin of cheek and mandible Muscles of Mastication
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The term mastication refers to the process of chewing. These muscles move the mandible at the temporomandibular joint. There are four paired muscles of mastication: the temporalis, the masseter, and the lateral and medial pterygoids The muscles of mastication are innervated by the mandibular division of CN V
(trigeminal nerve)

Superficial Muscles
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Temporalis
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Elevates and retracts mandible O: Superior and inferior temporal lines
I: Coronoid process of mandible Masseter
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Elevates and protracts mandible; prime mover of jaw closure
O: Zygomatic arch
I: Coronoid process, lateral surface and angle of mandible

Deep Muscles
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Medial pterygoid
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Elevates and protracts mandible; produces side-toside movement of mandible
O: Maxilla, palatine, and medial surface of lateral pterygoid plate
I: Medial surface of mandibular ramus

Lateral pterygoid
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Protracts mandible; produces side-toside movement of mandible O: Greater wing of sphenoid and lateral surface of lateral pterygoid plate
I: Condylar process of mandible What Muscles Are Involved??

What Muscles Are Involved??

What Muscles Are Involved??

What Muscles Are Involved??

What Muscles Are Involved??