Facial Bones

Question 1

Identify all of the facial bones? Which are single and which are paired?

Answer 1

2 maxillae
2 zygomatic
2 lacrimal
2 nasal
2 inferior nasal conchae
2 palantine
1 vomer
1 mandible
=14 total

Question 2

What facial bone makes up the prominence of the cheek?

Answer 2

zygomatic or malar bones

Question 3

What is the largest immovable facial bone?

Answer 3

the 2 maxillary bones

Question 4

What 7 bones make up the orbit?

Answer 4

Frontal, sphenoid, ethmoid, maxilla, zygomatic, lacrimal and palantine

Question 5

What projection best demonstrates the orbits?

Answer 5

Modified parietoacanthial waters

Question 6

What projection best demonstrates the optic foramina? Where should the optic foramina be demonstrated on the radiograph?

Answer 6

Parietoorbital Rheese method, the optic foramen is in the LOQ of orbit

Question 7

Describe the blow-out fracture?

Answer 7

Occurs when front or base of the orbit is struck solidly, orbital floor fractures and orbital contents blow out the orbital floor

Question 8

Describe the tripod fracture?

Answer 8

Results from a direct blow to the cheek. Fx at 3 points of attachment of the zygomatic bone: maxilla, temporal and frontal. Results in a free floating zygomatic bone.

Question 9

Where are the petrous ridges located in the following:
PA Caldwell
Waters
Modified Water

Answer 9

• lower 1/3 of orbits
• just below maxillary sinuses
• lower 1/3 of maxillary sinuses

Question 10

What bones form the bony nasal septum?

Answer 10

Superiorly- perpendicular plate
Inferiorly-vomer
Anteriorly-septal cartilage

Question 11

Which facial bones are the most fragile?

Answer 11

Nasal and lacrimal bones

Question 12

What is cleft palate?

Answer 12

A common congenital defect when there is an incomplete joining of the two palatine processes of the maxilla at birth

Question 13

What projection can be done if both zygomas are not demonstrated on the SMV?

Answer 13

the tangential oblique axial zygoma SMV

Question 14

What is the function of the facial bones?

Answer 14

To contribute to the shape and form of a persons face

Question 15

Is AP or PA preferred for headwork? Why?

Answer 15

PA is preferred for head work because when done AP the lens of the eye received 95% more radiation than when done PA

Question 16

What passes through the optic foramen?

Answer 16

The optic nerve

Question 17

What makes up the temporomandibular joint?

Answer 17

the mandibular condyle fitting into the temporomandibular fossa of the temporal bone

Question 18

What are the basic projections done to demonstrate the mandible? What are the additional ones?

Answer 18

basic: bilateral axial obliques
PA mandible
AP axial Low Down Towne
additional: SMV and panorex

Question 19

What are the basic projections for demonstrating the TMJ’s? Additional?

Answer 19

basic: AP axial modified towne
Additional: axiolateral obis modified law method
axiolateral schuller method
panorex
tomography

Question 20

How are TMJs taken radiographically?

Answer 20

bilaterally open and closed mouth

Question 21

Where is the mandibular condyle when the mouth is open? Closed?

Answer 21

open-condyle moves forward to the front edge of the fossa

closed-condyle lies within the temporomandibular fossa

Question 22

For the axiolateral oblique projections of the mandible what should be done to best visualize the mentum? Ramus? Body? General survey?

Answer 22

metum-turn head 45 degrees towards IR
Ramus-head in true lateral position
body-head turned 30 degrees towards IR
general survey-head turned 10-15 degrees towards the IR

Question 23

Explain the differences in the AP towne for skull, mandible and TMJ:

Answer 23

1. skull-angle CR 30 degrees caudal to 2.5” above glabella w/ OML and MSP perp
2. Mandible- angle CR 35-40 degrees caudal to the glabella w/ OML and MSP perp
3. TMJ- angle CR 35 degrees caudal at the level of the TMJ and 2” anterior to EAM w/ OML and MSP perp.

Question 24

Describe how the orbits project into the skull?

Answer 24

• cone shaped bony walled structure
• they project both upward and toward the midline.
• when OML is parallel to the floor the orbit projects 30 degrees superiorly and towards the MSP at a 37 degree angle.

Question 25

Describe the inner and outer portions of the orbit:

Answer 25

• the outer circular portion is called the base

- the inner most posterior portion is the apex, and this is where the optic foramen is located.

Question 26

What is a deviated nasal septum?

Answer 26

occurs when the nasal septum is deflected or laterally displaced from the midline of the nose at the junction of the septal cartilage and the vomer

Question 27

What does the maxillae articulate with?

Answer 27

2 cranial, 7 facial

• frontal and ethmoid
• zygomatic, lacrimal, nasal, palantine, inferior nasal conchae, vomer, and opposite maxilla.

Question 28

What does the zygomatic bones articulate with?

Answer 28

3 cranial, 1 facial

• frontal, sphenoid and temporal
• a maxilla

Question 29

What does the lacrimal bones articulate with?

Answer 29

2 cranial, 2 facial

• frontal and ethmoid
• maxilla and inferior nasal conchae

Question 30

What does the nasal bones articulate with?

Answer 30

2 cranial 2 facial

• frontal and ethmoid
• maxilla and opposite nasal bone

Question 31

What does the inferior nasal conchae bones articulate with?

Answer 31

1 cranial, 3 facial

• ethmoid
• maxilla, lacrimal and palantine

Question 32

What does the palantine bones articulate with?

Answer 32

2 cranial 4 facial

• sphenoid and ethmoid
• maxilla, inferior nasal conchae, vomer, and opposite palantine

Question 33

What does the vomer articulate with?

Answer 33

2 cranial 4 facial

• sphenoid and ethmoid
• both palantines and both maxilla