Chapter 11 FACIAL BONES/ORBITS

The superior and middle conchae are part of what cranial bone?

Ethmoid bone

nasal bone articulates with

Ethmoid, nasal septum, frontal bone, maxillae

Where is the CR for a waters nasal projection?

Exits @ acanthion

Modified Waters Facial Bones

Floor of orbits (blowout fractures)

Which process of the maxilla is most superior?

Frontal process

Which facial bones form the posterior aspect of the hard palate?

Horizontal portion of the palatine bones

Parietoacanthial (Waters) facial bones

Inferior orbital rim, maxillae, nasal septum, nasal spine, zygomatic bone and arches.

Th zygoma forms much of _____ and some of the floor of the orbit.

Lateral wall

inferior orbital fissure

Located between the maxilla, zygomatic bone, and greater wing of the sphenoid Allows transmission of the maxillary branch of CN V, permits entry of sensory innervation of the cheek, nose, upper lip, & teeth.

A portion of the _____ helps to form the floor of the orbit.

Maxilla

Where is the CR for the orbits Rhese method?

Mid portion of the downside orbit

Where does the CR exit for a 15 degree PA (Caldwell) projection for the facial bones?

Nasion

Which modality is helpful for diagnosing occult facial bone fractures?

Nuclear medicine

Which facial bone structures are best seen with a parietoacanthial projection?

Orbits (infraorbital rims), bone nasal septum, maxillae, zygomatic bones & arches

The one pair of facial bones not visible from the exterior view is??

Palatine bones

Lateral Nasal Bones

Profile image of nasal bones and nasal septum

Give to reasons why projections of the facial bones are performed PA rather than AP when possible.

Reduces OID Less exposure to anterior facial bones and thyroid glands

The orbital plate of the frontal bone forms most of the _____ of the orbit.

Roof

A deviated nasal septum is most likely to occur at the junction between _______ & _________.

Septal cartilage, vomer (pushed laterally to one side)

Each orbits is composed of parts of?

Seven bones

Which bone does not articulate with the zygomatic bone?

Sphenoid

palatine bone articulates with

Sphenoid, ethmoid, maxilla, inferior nasal conchae, vomer, & adjacent palatine bone

temporomandibular joint (TMJ)

Synovial (bicondylar) & plane (gliding)

If optic foramen is in upper quadrant of orbit, what positioning error was committed?

Too much flexion; not enough extension

A "free floating" zygomatic bone is the frequent result of a _____ fracture

Tripod

An increase in Kv of 25 to 30 percent is required for geriatric patients with advanced osteoporosis?

True

If optic foramen is behind lower quadrant, what positioning error was committed?

Under rotation

The one singe facial bone not visible from the exterior view is?

Vomer

Which facial bones are located internally?

Vomer & two palatine bones

Are lateral projections for nasal bone generally taken bilaterally for comparison?

Yes, that is true.

Where is the CR located for a lateral pos for facial bones?

Zygoma

Which facial bones are sometimes called the "cheek bones?"

Zygomatic or malar bones

The rim of the orbit, which corresponds to the outer circular portion of the cone, is called?

base

What is the name of the fracture that results from a direct blow to the orbit leading to a disruption of the inferior orbital margin?

blow out fracture

What is the major disadvantage of performing a straight PA projection for facial bones, with no CR angulation or neck extension, as compared with other PA facial bone projections?

dense petrous pyramids superimpose the orbits, obscuring facial bone structures

inferior nasal conchae articulates with

ethmoid, maxillae, palatine bones, lacrimal bones

Which two cranial bones articulate with the maxilla?

frontal and ethmoid bones

Which facial bone opening has the maxillary branch of fifth cranial nerve passing through it?

inferior orbital fissure

The _____ & _____ bones are the thinnest and most fragile bones in the entire body.

lacrimal and nasal

Which facial bone is associated with the tear ducts?

lacrimal bones

Which facial bones articulate at a joint instead of a suture?

mandible

What is largest immovable bone of the face?

maxillary bones

For a parietoacanthial PA Waters projection, the petrous ridges should be projected directly below the ______ and projected into the lower half of the maxillary sinuses or below the _______ for a modified Waters projection

maxillary sinuses; inferior orbital rims

What is a another term for the second cranial nerve?

optic nerve

Which structures specifically are visualized better on the modified Parietoacanthial (Waters) projection as compared with the basic Waters projection?

orbital rims and orbital floors

sphenoid strut

small root of bone that separates the superior orbital fissure from the optic canal

vomer articulates with

sphenoid, ethmoid, palatine bones, maxillae, cartilage of nasal septum

Which one of the facial bone openings is formed by a cleft between the greater and lesser wings of the sphenoid bone?

superior orbital fissure

mandible articulates with

temporal bone

Which two bones form the nasal septum?

vomer and ethmoid

maxilla articulates with

( two cranial bones) frontal & ethmoid bones. ( seven facial bones) nasal, vomer, inferior nasal conchae, palatine, lacrimal & adjacent maxilla.

Zygomatic bone articulates with

(Three cranial bones) frontal, sphenoid & temporal (One facial bone) maxilla

lacrimal bones articulate with

(Two cranial bones) frontal & ethmoid (Two facial bones) maxilla & inferior nasal conchae

The modified parietoacanthial (Modified Waters) projection requires that the ____ line is perpendicular to the IR, which places OML at a ____ angle to the tabletop and IR.

-LML; 55 degree

The parietoacanthial (Waters) projection for the facial bones has the _____ line perpendicular to the IR, which places the orbitalmeatal line (OML) at a ____ angle to the tabletop and IR.

-MML; 37 degrees

At what age does the mandible in an infant become one?

1 year

Where is the CR for bi-lateral nasal bone projection?

1/2 inch inferior to nasion (inner canthus); IOML perpendicular to IR

The bones of the orbit are:

3 (cranial): frontal, sphenoid, & ethmoid 4 (facial): maxilla, zygoma, lacrimal, palatine

What CR angle must be used to project the petrous ridges just below the orbital floor with the PA axial (Caldwell method) projection?

30 degrees caudad

From anterior to posterior, the cone-shaped orbits project upward at an angle of ____ and toward the midsagittal plane at an angle of____

30; 37

superior orbital fissure

A cleft or opening between the greater and lesser wings of the sphenoid bone, located lateral to the optic foramen. It allows transmission of four primary cranial nerves, controls movement of the eye & eyelid

Orbits Rhese method

AML perpendicular to IR Chin, cheek, nose touch table Rotate head 37 degrees, toward affected side -optical foramen in lower quadrant of the orbit.

Where is the CR for a parietoacanthial (Waters) projection of the facial bones?

Acanthion

Which soft tissue landmark is found at the base of the anterior nasal spine?

Acanthion

What are the four process of the maxilla?

Alveolar, palatine, zygomatic, & frontal process

cleft palate

An opening between the palatine processes that is caused by incomplete joining of the two bones

The posterior portion of the cone, the ____, corresponds to the _____.

Apex; optic foramen

Which modality is ideal for facial bone studies?

CT

The majority of the nose is formed by what?

Cartilage

What are two positioning differences between the lateral projection of the cranium and the lateral projection for the facial bones.

Cr placement IR (lengthwise for facial; crosswise for cranium)