Muscles of Facial Expression - Vocabulary Flashcards

Vocabulary-style flashcards covering key muscles, nerves, bones, and landmarks from the lecture notes on facial expression and anatomy.

Muscles of facial expression

Group of facial muscles derived from the second pharyngeal (hyoid) arch innervated by the facial nerve (VII) that move the skin and soft tissues of the face to create expressions (includes platysma).

Facial nerve (VII)

Cranial nerve supplying motor innervation to most muscles of facial expression; arises from the brainstem and exits the skull via the stylomastoid foramen.

Second pharyngeal arch (hyoid arch)

Embryologic arch giving rise to muscles of facial expression and related structures; associated with VII nerve development.

Subcutaneous muscles of facial expression

Muscle group in regions with relatively thick subcutaneous tissue, allowing greater mobility for facial expressions.

Areas with little subcutaneous tissue

Regions where skin is tightly bound to bone (e.g., upper nose, orbital margins, forehead, zygomatic arches, lower mandible).

Modiolus

Fibromuscular point at the corner of the mouth where several superficial lip muscles insert; key landmark for perioral muscle action.

Levator labii superioris alaeque nasi (LLSAN)

Elevates the upper lip and the nostril; part of the superficial layer of facial expression muscles.

Levator labii superioris

Elevates the upper lip.

Levator anguli oris

Elevates the angle of the mouth (corners upward) to assist smiling.

Zygomaticus major

Elevates the angle of the mouth; a primary muscle in smiling.

Zygomaticus minor

Elevates the upper lip; assists in smiling.

Risorius

Draws the corner of the mouth laterally; contributes to a grin.

Depressor labii inferioris

Depresses the lower lip.

Depressor anguli oris

Depresses the corner of the mouth (frowning).

Mentalis

Elevates and wrinkles the chin; protrudes the lower lip.

Orbicularis oris

Sphincter around the mouth; closes, protrudes, and purses lips; attaches variably to modiolus and surrounding skin/mucosa.

Buccinator

Cheek muscle deep in the cheek; aids chewing and keeps cheek against teeth; attaches to the pterygomandibular raphe and inserts into modiolus and orbicularis oris.

Orbicularis oculi

Muscle around the orbit with orbital and palpebral parts; closes eyes; orbital part contributes to wrinkle patterns (crow's feet).

Orbital part of orbicularis oculi

Part surrounding the orbital area; closes the eye forcefully.

Palpebral part of orbicularis oculi

Part within the eyelids; closes the eye gently during blinking.

Frontalis

Frontal belly of the occipitofrontalis; raises eyebrows and wrinkles the forehead; moves the scalp.

Occipitalis

Posterior belly of the occipitofrontalis; works with frontalis to move the scalp.

Epicranial aponeurosis

Tendinous sheet linking frontalis and occipitalis; allows coordinated movement of the scalp; loosely attached to the skull.

SCALP layers

Five layers: Skin, Connective tissue, Epicranial aponeurosis, Loose connective tissue, Periosteum.

Procerus

Muscle at the root of the nose producing transverse nasal wrinkles; part of facial expression around the glabella.

Nasolabial fold

Line from the side of the nose to the corner of the mouth; becomes prominent with facial movement and aging.

Marionette lines

Vertical lines extending from the corners of the mouth toward the chin; associated with depressor anguli oris and aging.

Gummy smile

Excessive gingival display when smiling; often due to hyperactive levator labii superioris alaeque nasi; can be treated with Botox.

Hyperactive levator labii superioris alaeque nasi

Overactive muscle elevating the upper lip and nasal wing; contributes to a gummy smile.

Retromolar triangle

Area behind the last molar; landmark for cheek/muscle attachments and palpation in some assessments.

Levator anguli oris

Elevates the angle of the mouth (smiling action).

Levator labii superioris alaeque nasi vs. levator labii superioris difference

LLSAN elevates the upper lip and nostril; Levator labii superioris primarily elevates the upper lip.

Nasolabial region attachments (soft tissue focus)

Muscles of facial expression often attach to soft tissues around the lips and nose rather than to bone.

Deep vs superficial lip muscles

Superficial layer includes LLSAN, levator anguli oris, zygomaticus major/minor, risorius, depressors, mentalis; deep layer includes buccinator and orbicularis oris.