Orbits and Facial Bones

What line is parallel to the IR in the SMV of zygomatic arches?

IOML

What line is parallel with he long axis of the cassette for laterals?

IOML

What line is perpendicular to the IR for the modified townes of the facial bones at 37º caudal angle?

IOML

Which line is parallel to the IR doe the tangential projection of the zygomatic arches?

IOML

What shape are the palatine bones?

L shaped

What line is perpendicular to the IR when shooting a modified waters?

MML

What line is perpendicular to the IR when shooting a reverse waters?

MML

What line is perpendicular to the IR when shooting a waters?

MML

What plane is parallel to the IR for laterals?

MSP

What plane is perpendicular to the IR in a modified waters of the orbit?

MSP

Where do the 2 nasal bones articulate with each other?

MSP

What line is perpendicular to the IR for the Caldwell of the facial bones?

OML

What line is perpendicular to the IR for the modified townes of the facial bones at 30º caudal angle?

OML

Which baseline is used to position the parietoacanthial (modified Waters) projection of the eye?

OML

In what projections of the skull can you visualize the lacrimal bones?

PA and lateral

Which special projection of the eye involves the use of the CR angulation to project the petrous ridges out of the orbits?

PA axial

What is the 3 point landing projection?

Rhese

Which projections shows a bilateral view of the zygomatic arches without superimposition?

SMV of the zygomatic arches

What is the only freely movable joint of the face?

TMJ

What is the midpoint of the anterior nasal spine referred to as?

acanthion

Where do you center for a reverse waters?

acanthion

What type of bone is the hyoid in relation to the axial skeleton?

accessory bone

Which bones does the maxilla articulate with?

all facial bones except the mandible

What are the boney features that provide attachments for the teeth called (on the maxilla and mandible)?

alveolar processes

How do you angle the tube for a reverse waters, in a trauma situation, where the patient cannot tilt his had to make his OML 37º from the IR?

angle to be parallel to the MML

In the anterior MSP at the junction of the two maxillary bones, a forward-projecting process is formed. What is it called?

anterior nasal spine

Where are the petrous ridges in a waters?

below apex of maxillary sinus

Where are the petrous ridges in a modified waters?

below orbits, midway through maxillary sinus

Define Le Fort fracture

bilateral, horizontal fractures of the maxilla

What is the curved horizontal portion of the mandible called?

body

What is the superior boney wall of the nasal cavity more commonly known as?

bridge of the nose

What touches the Bucky for the Rhese?

cheek, nose, chin

What touches the Bucky for a waters?

chin, nose 3/4 inch away

What is the TMJ formed by?

condyle of the mandible and the mandibular fossa of the temporal bone

Where is the TMJ located in relation to the EAM?

directly in front

Define TMJ syndrome

dysfunction of the TMJ

Medial back side of orbit...

ethmoid

The upper 2 nasal conchae are processes of what bone?

ethmoid

Where do you center for a modified waters of the facial bones?

exiting the acanthion

Where do you center for a waters of the facial bones?

exiting the acanthion

Where do you center for the PA axial Caldwell of the facial bones?

exiting the nasion

What type of joints are the alveolar sockets?

fibrous, gomphosis, immovable

Define blowout fracture

fracture of the floor of the orbit

Define tripod fracture

fracture of the zygomatic arch and orbital floor or rim, and dislocation of the frontozygomatic suture

Define contre-coup fracture

fracture to one side of the structure caused by trauma to the other side

Roof of the orbit...

frontal

What does the zygoma articulate with superiorly?

frontal

What 2 cranial bones does the maxilla articulate with?

frontal and ethmoid

What do the nasal bones articulate with superiorly?

frontal bone

What 4 bones does the lacrimal bone articulate with?

frontal, ethmoid, maxilla, inferior nasal concha

Three of the bones making up the orbit are cranial bones - what are they?

frontal, sphenoid, ethmoid

List the 7 bones that make up the orbit

frontal, sphenoid, ethmoid, maxilla, zygoma, lacrimal, palatine

What 3 bones make up the outer rim of the orbit?

frontal, zygoma, maxilla

What is another term for the angle of the mandible?

gonion

What is the name of the U shaped bone, situated at the base of the tongue?

hyoid

Define osteopetrosis

increased density of atypical soft bone

What bones extend diagonally and inferiorly from the lateral walls of the nasal cavity, curling laterally giving them a scroll-like appearance?

inferior nasal conchae

Define osteomyelitis

inflammation of the bone due to pyogenic infection

What passes through the infraorbital foramen?

infraorbital nerve and artery

What line is perpendicular to the IR for laterals?

interpupillary line

Anterior part of the medial wall of orbit...

lacrimal

Which facial bone is located at the medial wall of the orbit?

lacrimal

What are the smallest bones of the skull?

lacrimal bones

Where do the tear ducts pass through?

lacrimal foramina

Which projections are used to demonstrate radiopaque foreign objects in the eye?

lateral, PA axial, modified Waters

Why are special projections of the eye done?

localize radiopaque foreign bodies in the eye

Define osteoporosis

loss of bone density

Where are the petrous ridges for the Caldwell of the facial bones?

lower 1/3 of the orbit

What is another name for the zygomatic bone?

malar bone

Where is the mental foramen located?

mandible

What are the two processes of each ramus of the mandible separated by?

mandibular notch

Part of the floor of the orbit...

maxilla

What does the zygoma articulate with anteriorly?

maxilla

What is the largest immovable bone of the face?

maxilla

Where is the infraorbital foramen located?

maxilla

What 4 facial bones make up the orbit?

maxilla, zygoma, lacrimal, palatine

What do the nasal bones articulate with on each lateral side?

maxillae

The mandible fuses within the first year of life. What is the ridge at which it fuses called?

mental protuberance

Where do you center for the modified waters of the orbit?

midorbit

What projections best shows a blowout fracture?

modified waters

What portion of the nasal cavity does the maxilla form?

most of the lateral portion and floor of the nasal cavity

What are the inferior nasal conchae covered with and why?

mucous membrane - to warm, moisten, and cleanse inhaled air

Is the mandible a paired bone?

no

What touches the Bucky for a modified waters?

nose and chin

What structures are shown on a waters facial bones?

orbits, maxilla, zygomatic arches

Where do you center for the lateral orbit?

outer canthus

Posterior part of the medial wall of orbit...

palatine

Which facial bone is located at the inferior apex of the orbit?

palatine

Which facial bone is located at the posterior portion of the roof of the mouth?

palatine

What makes up for the other 1/4 of the roof of the mouth

palatine bones

Which special projection of the eye involves the use of part position to project the petrous ridges out of the orbits?

parietoacanthial projection (modified Waters method)

What portion of the orbit does the maxilla form?

part of the floor of the orbital cavities

What part of the orbit do the palatine bones make up?

part of the posteromedial portion

What part of the orbit does the zygomatic bone make up?

part of the side wall and floor

What are the two vertical portions of the mandible called?

rami

Which facial bone projection demonstrates the superior facial bones with magnification?

reverse waters method

How do you position a tangential projection of the zygomatic arches?

rotate the MSP 15º towards the side of interest, tilt the top of the head 15º away from the side of interest

When shooting PA, which side are we looking for?

side down

Which side are you looking for in a Rhese?

side down

Lateral back side of orbit...

sphenoid

What does the zygoma articulate with posteriorly?

sphenoid

What structures are shown on a reverse waters?

superior facial bones

What are the structures shown on the AP axial modified townes of the zygomatic arches?

symmetric projection of both zygomatic arches, free of superimposition

What type of joint is the TMJ?

synovial, hinge and gliding, freely movable

How does the hyoid relate to the facial bones?

the hyoid is held in place by the stylohyoid ligaments, which extend from the styloid processes of the temporal bones

What forms the zygomatic arch?

the junction of the zygomatic process of the temporal bone and the temporal process of the zygomatic bone

What structures are shown on a Rhese?

the optic foramen lying in the inferior and lateral quadrant of the projected orbit

Where does the maxilla articulate with the zygoma?

the zygomatic process

What bone is situated on the MSP on the floor of the nasal cavity?

vomer

Which facial bone forms the inferior portion of the nasal septum?

vomer

What method is the parietoacanthial projection?

waters, modified waters

Where are the petrous ridges in a modified waters of the orbit?

well below orbital shadows

When is the tangential projection of the zygomatic arch particularly useful?

when a patient has a depressed fracture or flat cheekbones

What is cleft palate?

when the maxilla does not fuse together properly

When is a reverse waters done?

when the patient cannot be placed PA

Are the sphenoid, palatine, and maxilla all parts of the bony labyrinth?

yes

Does the maxilla contain paranasal sinuses?

yes

Does the maxilla feature special bone that holds the roots of the teeth?

yes

Can a Rhese be done AP?

yes, but eye dose will increase

Part of the lateral wall and floor of the orbit...

zygomatic

Which facial bone features a frontal process?

zygomatic

What does the zygoma articulate with laterally?

zygomatic process of temporal bone

Structures shown on the tangential projection of the zygomatic arch?

1 arch, free of superimposition

What two processes do each ramus of the mandible present?

1 coronoid, 1 condylar

Where do you center for a Rhese?

1" above and 1" posterior to the TEA

Where do you center for the SMV of the zygomatic arches?

1" posterior to the outer canthus

Where do you center for the tangential projection of the zygomatic arches?

1" posterior to the outer canthus

2 evaluation criteria for lateral of the facial bones?

1. Superimposed orbital roofs 2. Sella turcica in profile

2 evaluation criteria for the Rhese

1. entire orbital rim 2. supraorbital margins lying in the same horizontal line

2 evaluation criteria for modified waters of the orbit

1. entire orbits 2. petrous ridges well below orbital shadows

2 evaluation criteria for lateral orbit

1. entire orbits 2. superimposed orbital roofs

2 evaluation criteria for the reverse waters of facial bones

1. entire orbits and facial bones 2. petrous ridges projected immediately below maxillary sinuses

2 evaluation criteria for waters of the facial bones

1. entire orbits and facial bones 2. petrous ridges projected immediately below maxillary sinuses

2 evaluation criteria for the Caldwell of the facial bones

1. entire orbits and facial bones 2. petrous ridges projected in the lower 1/3 of orbit

2 evaluation criteria for the modified waters of the facial bones

1. entire orbits and facial bones 2. petrous ridges projected midway through the maxillary sinuses

2 evaluation criteria for the AP axial modified townes of the zygomatic arches

1. no overlap of zygomatic arches by mandible 2. symmetric arches

Evaluation criteria for tangential projection of the zygomatic arch

1. zygomatic arch free from overlying structures

2 evaluation criteria for SMV of zygomatic arches

1. zygomatic arches free from overlying structures 2. zygomatic arches symmetric and without foreshortening

Where do you center for the lateral facial bones?

1/2 distance from OC to EAM

How many facial bones are there?

14

What is the angle of the CR in a PA axial Caldwell of the facial bones?

15º caudal

How many mental foramen do you have?

2, they are bilateral

How much of the roof of the mouth does the maxilla make up?

3/4

What is the central ray orientation for the PA axial special projection of the eye?

30º caudal

What angle is the OML at for a reverse waters?

37º

What angle is the OML at for the waters?

37º

What is the SID for all facial bones?

40"

What angle is the MSP at in a Rhese?

53º

What angle is the OML at for the modified waters?

55º

What angle should the OML be at in a modified waters of the orbit?

55º

How many bones is the orbit composed of?

7

What kVp are most all facial projections shot at?

80 kVp

What is the exaggerated Caldwell and what does it show?

Caldwell with a 30º angulation to show the orbital rims, particularly the orbital floors