Facial Bones, Orbits, Sinuses

Facial bones are also called ___

visceral cranium

What are the functions of the facial bones?

• framework/structure

• brain and eye protection

What is the classification of the joints of the frontal bones?

fibrous, synarthrodial

How many facial bones are there?

6 paired

2 unpaired

14 total

What is the largest immoveable facial bone?

maxilla

Is the maxilla paired?

YES

The infraorbital foramen is located on the ___

maxillae

The maxilla forms ___

• floor of orbit

• lateral wall of nasal cavity

• roof of mouth

List and explain the 4 processes of the maxillae

• frontal

  • articulates with frontal bone

• alveolar

  • holds the teeth

• palatine

  • roof of the mouth

• zygomatic

  • articulates with zygoma

The zygoma forms ___

• lateral wall and floor of orbit

• upper cheekbone (zygomatic arches)

Is the zygoma paired?

YES

List and explain the 3 processes of the zygoma

• frontal

  • articulates with frontal bone

• maxillary

  • articulates with maxilla

• temporal

  • articulates with temporal bone

Explain the tripod fracture

a fracture at all three of the zygoma’s processes

What does SMV stand for?

submentovertex

Is the nasal bone paired?

YES

Is the lacrimal bone paired?

YES

The nasal bone forms ___

the bridge of the nose

The lacrimal bone forms ___

medial orbital wall (between ethmoid and maxilla)

Where are the tear ducts located?

lacrimal bones

What is the smallest facial bone?

lacrimals

Is the palatine bone paired?

YES

Where are the palatine bones located?

posterior to the maxillae, anterior to the sphenoid

List and explain the 2 portions of the palatine bones

• vertical

  • lateral walls of the nasal cavity and orbit

• horizontal

  • posterior portion of the hard palate

Is the inferior nasal conchae paired?

YES

What is another name for the inferior nasal conchae?

inferior turbinates

Where are the inferior nasal conchae located?

extend medially from the lateral wall of the nasal cavity

What is the function of the inferior turbinates?

filter and circulate air coming into the nasal cavity

Is the vomer paired?

NO

The vomer forms ___

the lower portion of the bony nasal septum

Is the mandible paired?

NO

What is the largest moveable facial bone?

mandible

List the 3 structures of the mandible (and the features located on each)

• body (horizontal portion)

  • symphysis

  • mental protuberance - chin

  • alveolar portion

  • mental foramen

• angle (gonion)

• ramus (vertical portion)

  • coronoid process

  • condylar process/head

    • head, neck

    • mandibular notch

    • TMJ joint

What is the classification of the TMJ?

diarthrodial, synovial, condylar/ellipsoidal

What are the orbits?

cone-shaped, bony walled cavities that hold the eyes

Explain the apex and base of the orbits

apex

• corresponds to the optic canal

• optic nerve (2nd cranial nerve)

base

• frontal bone, zygoma, maxilla

What 7 bones make up the orbit?

• frontal

• sphenoid

• ethmoid

• palatine

• maxilla

• zygoma

• lacrimal

List and explain the 4 sections of the orbits

• roof

  • frontal and sphenoid

• floor

  • maxilla, zygoma

• lateral wall

  • zygoma

• medial wall

  • maxilla, lacrimal, ethmoid, palatine

What are the optic foramen?

• the apex of the orbit

• 2nd cranial nerve (optic nerve) leaves the eye via this foramen

What are the superior orbital fissures?

comma-shaped aperture located superiorly on the grater wing of the sphenoid

What are the inferior orbital fissures made up of?

sphenoid, maxilla, and zygoma

The apex of the bony orbit is at a ___ angle with MSP

37^o

The apex of the bony orbit is at a ___ angle with OML

30^o

Explain the blowout fracture

• caused by an object striking the eyes straight on

• direct blow causes eyeball to “blow out” the thin bony floor of the orbit due to increase in pressure

• inferior rectus muscle forced through the fracture into the maxillary sinus

Explain foreign bodies in the orbits

• metal or other fragments in the eye

• pre-MRI

  • history of FB in the eye

  • metal fragment could move and sever optic nerve

What are the functions of the nasal cavity?

• warms air to body temperature

• humidifies

• removes dust particles

What is a deviated nasal septum?

deviation between the cartilage and the vomer

What are the paranasal sinuses?

• near the nose

• resonating chamber for sound

• decreases the weight of the skull

• warms and moistens inhaled air

• housed within 3 cranial bones and 1 facial bone

Explain the frontal sinus

• most superior

• in squamous portion of frontal bone

• vary greatly in size and form (2nd largest sinus)

Explain the ethmoid sinus

• located within the lateral masses in the ethmoid bone

• composed of varying number of air cells divided into 3 groups (anterior, middle, and posterior)

Explain the maxillary sinus

• largest sinus

• pyramidal in shape (usually symmetrical)

• located within maxillary bone

• the only sinus that is aerated at birth

• aka the Antrum of Highmore

Explain the sphenoid sinus

• paired

• vary greatly in size and shape (usually asymmetrical)

• located in the body of the sphenoid bone

• most posterior sinus

Sinuses are best seen in the ___ position

upright

The osteomeatal complex is ___

the common pathway for drainage and ventilation

What is exudate?

the pus/snotty fluid that fills the sinuses

When do the paranasal sinuses develop?

maxillary: at birth

frontal: age 7

sphenoidal: age 7

ethmoidal: age 18