Test 2: Muscles of Facial Expressions & Tongue, Foramens, Sinuses

Functions of Paranasal sinuses

• lighten the weight of the skull

• Resonate sound

• Provide mucous

Mucous aids in:

• moisturizer/tissue conditioner

• Antibacterial/antifungal/antiviral

Clinical considerations of Paranasal Sinuses

• visible on radiographs (maxillary)

• Proximity of roots of posterior teeth

• Sinus pain may be felt as dental pain

• Sinus congestion → limit use of water and worsens when patient is reclined

Hyoid bone

Infratemporal fossa

Boundaries

1. Superior - greater wing of sphenoid & temporal bone

2. Anterior - maxillary tuberosity

3. Lateral - medial surface of ramus

4. Medial - lateral surface of lateral pterygoid process

Pterygopalatine fossa

Infratemporal fossa is an important landmark bc ___

Many muscles, nerves, and blood vessels pass through this fossa

Pterygopalatine fossa is an important fossa bc ___

Contains numerous nerves, a ganglion, and blood vessels that supply the oral cavity

Pterygomaxillary fissure is the ___

“Door frame” between the Infratemporal fossa & Pterygopalatine fossa

Pterygomaxillary fissure

Foramen lacerum junctions

• sphenoid bone

• Occipital bone

• Temporal bone

1. Stylomastoid foramen

2. Carotid canal

3. Foramen lacerum

4. Jugular foramen

1. Foramen lacerum

2. Jugular foramen

3. Foramen rotundum

4. Ovale foramen

5. Spinosum foramen

6. Hypoglossal canal

Epicranial Muscle

Epicranial muscle has:

Two bellies:

• frontal

• Occipital

Frontalis muscle

O - tendon the scalp

I - skin of eyebrows & root of nose

Occitpitalis muscle

O - occipital bone & mastoid process

I - tendon of the scalp

Frontalis muscle function

Raises the eyebrows; surprised

Orbicularis Oculi

O - orbital rim, frontal bone, maxilla

I - skin at lateral canthi, encircle the eye

Orbicularis Oculi components:

• orbital portion

• Palpebral portion

Orbital portion of Orbicularis Oculi function:

• forceful closure of the eye

• Protect and moisten the eye

Palpebral portion of Orbicularis Oculi function:

• within the eyelids

• Gentle closure of blink

1. Orbital portion

2. Palpebral portion

Orbicularis oculi

Corrugator Supercilii

O - superorbital region of the frontal bone, superior to the medial canthus

I - skin under central portion of the eyebrows

orbicularis oris

O - none on the bone

O & I - skin and fascia of the lips

orbicularis oris functions:

• closure, pursing of the lips

• rolling lips inward in between the teeth

• movement of lips during speech

Risorius muscle

O - fascia overlying the masseter muscle

I - skin at commissures

Risorius muscle function

extends commissures laterally → grimace

Buccinator muscle

O - Alveolar process of max & mand, pterygomandibular raphe/fold

I - labial commissures

Buccinator muscle functions:

• facial expressions: pulls commissures laterally to function with other muscles in smiling

• Mastication: compress cheeks to keep food on chewing surfaces of posterior teeth

• Wind instruments/whistle; expel air to produce sound; trumpet muscle

Zygomaticus major

O - zygoma

I - skin at commissures

Zygomaticus major function:

• raises & pulls commissure laterally

• functions with other muscles when smiling

zygomaticus minor

O - zygoma

I - skin of upper lip at max. canine area

zygomaticus minor function

elevation of the upper lip assist in smiling

Levator Labii superioris

O - inferior rim of orbit

I - skin of upper lip

Levator Labii superioris function

elevates upper lip

Levator Labii superioris alaeque nasi

O - frontal process of maxilla, near medial canthus

I - skin of the alae & upper lip below the alae

Levator Labii superioris alaeque nasi functions:

• elevates upper lip

• dilates the nostril

• sneer

depressor anguli oris

O - inferior border of mandibule

I - skin at commissures

depressor anguli oris functions:

• pulls commissures down

• frown

depressor labii inferioris

O - inferior border of mandibule medial to depressor anguli oris

I - skin of lower lip, medial to nguli oris muscle

depressor labii inferioris function

pulls lower lip down, shows the lower teeth

mentalis

O - midline of anterior surface of man; mental fossa

I - skin of chin

mentalis function

raise chin, displacing lower lip down in pout

platysma

O - skin over clavicle and shoulder

I - orbicularis oris at commissures AND inferior border of mand

platysma function

tenses neck, pulls commissures down, grimace

intrinsic muscles of the tongue

vertical fibers

extend from dorsal to venal surfaces

transverse fibers

extend from the median setpum to right and left lateral borders; work with vertical fibers to make tongue long & narrow

superior & inferior longitudinal muscle fibers

extend from apex to base of tongue on dorsal/ventral surfaces

• work together; shorten & thicken the tongue

• work individually; curl the tongue down/upward

extrinsic muscles of the tongue

O - areas outside the tongue

I - within the tongue

styloglossus muscle

O - styloid process

I - tongue: lateral border of body to apex

styloglossus muscle function

retracts tongue up and back

hyoglossus

O - hyoid bone

I - lateral border tongue

hyoglossus function

depresses tongue toward floor of mouth

palatoglossus muscle

O - median palatine raphe

I - lateral border of tongue

palatoglossus muscle functions:

• elevates tongue

• pulls soft palate down during swallowing

• forms palatoglossal arch

musculus uvulae

O - posterior border of hard palate

I - uvula

musculus uvulae function

close nasopharynx during swallowing

Corrugator Supercilii function

draw eyebrows down and together; frown

genioglossus muscle

O - genial tubercles

I - ventral surface of tongue from base to almost to apex

genioglossus muscle functions:

• protrude tongue out of mouth

• prevents tongue from dropping back and blocking the airway

Levator Anguli Oris

O - canine fossa of max; deep to zygomatic muscle

I - skin at commissures

Levator Anguli Oris function

pulls corner of mouth upwards during smiling