Myology

Muscles of the Face

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Muscles of Facial ExpressionEye Muscles

• Orbicularis oculi– Under both conscious/unconscious control i.e. blinking– When entire muscle is contracted eyelids & surrounding

area will be drawn medially decreasing amount of light entering eye

• Levator palpebrae superioris– Attaches from sphenoid bone to upper eyelid.– Nerve memory hint: columns (CN III) opens the eye.

• Corrugator supercilii– Draws eyebrows inferiorly/medially as in frowning

causing vertical wrinkles superomedially to eye.

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Orbicularis OculiO: Medial side of eye

I: Medial side of eye (returns to same attachment encircling the eye)

A: Closes & squints the eye. Also assists in tear transport and drainage

N: CN VII (Facial nerve)

Palpation: page 35

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Levator Palpebrae Superioris

O: Sphenoid Bone

I: Upper Eyelid

A: Elevates upper eyelid

N: CN III (Oculomotor nerve)

Palpation: page 38

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Corrugator Supercilii

O: Inferior frontal bone

I: Skin deep to medial eyebrow

A: Draws eyebrow inferomedially

N: CN VII (Facial nerve)

Palpation: page 40

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Muscles of Facial ExpressionNose Muscles

• Procerus– Often blends with frontalis superiorly and nasalis

inferiorly– Gives look of frowning and also helps shield eyes from

bright light– Person may convey air of superiority (hence “procerus”

meaning chief, noble or prince).• Nasalis

– Transverse part sometimes called compressor nasi and alar part dilatator nasi

– Blends with procerus superiorly• Depressor Septi Nasi

– Sometimes considered part of alar portion of nasalis

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Procerus

O: Fascia over nasal bone

I: Skin between eyebrows

A: Draws down medial eyebrows. Also wrinkles the skin of the nose

N: CN VII (Facial nerve)

Palpation: page 42

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Nasalis

O: Maxilla

I: Cartilage of Nose and Opposite side Nasalis muscle

A: Flares nostrils

N: CN VII (Facial nerve)

Palpation: page 44

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Depressor Septi Nasi

O: Incisive fossa of the maxilla

I: Cartilage of Nose

A: Constricts nostrils

N: CN VII (Facial nerve)

Palpation: page 46

Muscles of Facial ExpressionMouth Muscles

• Levator Labii Superioris– Main elevators of upper lip are levator labii superioris &

zygomaticus minor.– Contraction alone will elevate upper lip as in showing

someone our upper teeth.• Zygomaticus Minor

– Blends with levator labii superioris• Zygomaticus Major

– Contributes to smiling and laughing– 6 muscles attach into modiolus (fibro muscular condensation

≈ ¼” lateral to angle of mouth): zygomaticus major, levator anguli oris, risorius, depressor anguli oris, buccinator, & orbicularis oris.

Levator Labii Superioris

O: Inferior orbital margin of the maxilla

I: Upper Lip

A: Elevation of Upper Lip

N: CN VII (Facial nerve)

Palpation: page 51

Zygomaticus Minor

O: Zygomatic bone

I: Upper Lip

A: Elevation of Upper Lip

N: CN VII (Facial nerve)

Palpation: page 54

Zygomaticus Major

O: Zygomatic bone

I: Angle of Mouth

A: Elevation of Angle of Mouth as in smiling. Also draws laterally at the angle of the mouth

N: CN VII (Facial nerve)

Palpation: page 57

Muscles of Facial ExpressionMouth Muscles

• Levator Anguli Oris– Also known as the caninus because contraction

can result in teeth especially canine tooth becoming visible – “Dracula” expression.

– Contraction alone can manifest a sneer.

Levator Anguli Oris

O: Maxilla, just inferior to the infraorbital foramen

I: Angle of Mouth

A: Elevation of Angle of Mouth

N: CN VII (Facial nerve)

Palpation: page 60

Muscles of Facial ExpressionMouth Muscles

• Risorius– Drawing angle of mouth laterally is involved

with grinning, smiling, and laughing.• Depressor Anguli Oris

– Blends into the platysma– Contribute to facial expression of sadness or

uncertainty.• Depressor Labii Inferioris

– Contribute to facial expressions of sorrow, doubt, and irony.

Risorius

O: Fascia Superficial to Masseter

I: Angle of Mouth

Action: Draws Laterally the Angle of Mouth

N: CN VII (Facial nerve)

Palpation: page 63

Depressor Anguli OrisO: Mandible

I: Angle of Mouth

A: Depresses the Angle of Mouth. Also assists the risorius in drawing the angle of the mouth laterally

N: CN VII (Facial nerve)

Palpation: page 66

Depressor Labii Inferioris

O: Mandible

I: Lower Lip

A: Depression of Lower Lip. Also assists in drawing the lower lip laterally and everting it.

N: CN VII (Facial nerve)

Palpation: page 69

Muscles of Facial ExpressionMouth Muscles

• Mentalis– Contributes to facial expressions of doubt, pouting, or disdain

• Buccinator– Parotid duct pierces through buccinator to enter mouth– Action of compressing the cheeks against the teeth by the 2

buccinators working bilaterally is important for forcefully expelling air from the mouth.

• Latin word for trumpeter is “buccinator”– Important with whistling, blowing up a balloon and with helping keep

food from lingering in vestibule of mouth.– Contributes to expression (puckering the cheeks) made when person

eats something sour.

• Orbicularis Oris– Causes kips to close and protrude as in puckering lips or whistling.

MentalisO: Mandible

I: Skin of the Chin

A: -Elevation of Lower Lip -Eversion and Protracts the Lower Lip

- Wrinkles the skin of the chin

N: CN VII (Facial nerve)

Palpation: page 72

Buccinator

O: Maxilla and Mandible

I: Lips (buccinator muscle is located in the tissue of the cheek)

A: Compression of Cheeks (against teeth)

N: CN VII (Facial nerve)

Palpation: page 75

Orbicularis Oris

O: Surrounds the mouth

Action: Closes mouth and protracts the lips

N: CN VII (Facial nerve)

Palpation: page 77