Myology Muscles of the Face

Muscles of Facial Expression Eye 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.

Orbicularis Oculi O: 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

Levator Palpebrae Superioris O: Sphenoid Bone I: Upper Eyelid A: Elevates upper eyelid N: CN III (Oculomotor nerve) Palpation: page 38

Corrugator Supercilii O: Inferior frontal bone I: Skin deep to medial eyebrow A: Draws eyebrow inferomedially N: CN VII (Facial nerve) Palpation: page 40

Muscles of Facial Expression Nose 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

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

Nasalis O: Maxilla I: Cartilage of Nose and Opposite side Nasalis muscle A: Flares nostrils N: CN VII (Facial nerve) Palpation: page 44

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 Expression Mouth 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 Expression Mouth 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 Expression Mouth 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 Oris O: 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 Expression Mouth 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.

Mentalis O: 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