facial bones

Question 1

find and label anatomy of skull bones

Question 2

what are the 4 sinus found in the skull/face

Answer 2

• frontal sinus
• ethmoidal sinus
• sphenoidal sinus
• maxillary sinus

Question 3

describe how the 4 sinus structures sit in the skull from anterior to posteriro

Answer 3

anteriorly sits the frontal sinus ethmoidal sinus and maxillary sinus (going in that order from top to bottom)

then the sphenoidal sinus sits posterior to the ethmoid sinus slightly inferiorly

Question 4

what do you call the structure that separates the right and left frontal sinuses

Answer 4

intersinus septum

Question 5

what is the wall of the sinus cavities covered in and why

Answer 5

• mucus
• keeps tissue moist and healthy, and traps bacteria

Question 6

how does the mucus in the sinus help the air that passes through it down to the lungs

Answer 6

• helps humidify and filter the air

Question 7

the sinuses also help the voice resonate

Question 8

what is sinus the latin word for

Answer 8

curve or fold
(referred to system of hollow cavities in anatomy)

Question 9

where is the glabella, nasion, acanthion and mental point found on the face/skull

Answer 9

glabella = point between eyebrows above nose

nasion = beginning of nose bridge below glabella

acanthion = cupids bow (beneath nose)

mental point. = front / tip of jaw

Question 10

what are the 5 positioning lines of the face

Answer 10

• glabellomeantal line
• orbitomeatal line
• infraorbitomeatal line
• acanthiomeatal line
• mentomeatal line

Question 11

what is the Occipitomental view best for viewing

Answer 11

• upper and middle 3rd of face
• orbital margins
• frontal sinus
• zygomatic arches
• maxillary antra/sinus

Question 12

how should you raise the chin of the patient for an OM pa view

Answer 12

• raise the chin against the IR so that the OM line is 45 degrees cranial from the perpendicular line to the IR
• makes the mentomeatal line exactly perpendicular to the IR

Question 13

what is a an OM 30 good for seeing

Answer 13

• orbital margins (not orbits whole)
• zygomatic arches
• mandible

Question 14

for a PA mandible view, which positioning line should be parallel to the floor

Answer 14

• orbitomeatal line
• and the interpupillar line

Question 15

where is the beam centred for a PA mandible view

Answer 15

• point in the midline between the angles of mandible

Question 16

how can you tell if the head is rotated during a veiw

Answer 16

• check that the external auditory meatus (EAM) is equidistant from the detector

Question 17

how does the tilting of the head differer from a PA orbital view and a PA OM view

Answer 17

• PA orbital view only requires 35 degree tilt from horizontal instead of 45

Question 18

how should you collimate for PA orbital and where do you centre

Answer 18

• letter box collimation
• centre midpoint between orbits

Question 19

what should you see on a PA orbital view

Answer 19

• round not oval orbits
• petrous ridge projected below the orbits (found in the lower 3rd of maximally sinus)

Question 20

what is a blow out fracture of the orbit

Answer 20

• a blow to the globe causes increased intra-orbital pressure
• this causes fracture in thin plate of bone forming the floor of the orbit (also the roof of the maxillary antrum)
• some of the orbital contents e.g fat and muscle, herniate down into maxillary sinus

Question 21

what is a radiographic feature of a blow out fracture in the orbits

Answer 21

• soft tissue formed teardrop or polypoid mass in the roof of the maxillary antrum

Question 22

asses the zygoma by following the elephants trunk

Question 23

find a diagram and identify the frontal process, orbital process and body of the zygomatic bone

Question 24

what is the name of the foramen found in the zygomatic bone

Answer 24

zygomaticalfacial foramen

Question 25

if you spot a black eyebrow sign in a facial xray what can this indicate

Answer 25

• free air due to blow out fracture

Question 26

if you spot air-fluid level in the maxillary sinus, what can this indicate

Answer 26

blood due to fracture

Question 27

what are some direct radiological signs of a facial fracture

Answer 27

• non anatomic linear lucencies
• cortical defect/ widening of suture
• bone fragments overlapping causing double density
• asymmetry of face

Question 28

what are some indirect signs of facial fractures

Answer 28

• soft tissue swelling
• periorbital or intracranial air
• fluid in paranasal sinus

Question 29

because the mandible is a ring of bone, what does this mean about its fractures

Answer 29

likely to fracture at more than one point

Question 30

what is a quadripod or tripod fracture, also known as zygomaticomaxillary complex fracture

Answer 30

fracture to :
- zygomatic arch
- inferior and lateral orbital rim
- anterior and posterior maximally sinus walls

overall, separates the zygoma wall at all its attachments from the rest of the face

Question 31

difference between OM and OM 30 scan

Answer 31

OM = orbitalmeatal line 45 degrees cranially to receptor and the tube is perpendicular to receptor

OM 30 = same positioning as OM but the tube is angled 30 degrees caudally to the receptor

Question 32

if an examination is purely done to exclude foreign bodies from the orbits, what type of collimation should be done

Answer 32

letter box collimation

• reducing dose by not scanning what is not required

Question 33

during an OM orbital view, where is the petrous ridge seen

Answer 33

in the lower 3rd of the maxilla

Question 34

what 6 bones are the orbits made of

Answer 34

lacrimal
ethmoid
palatine
zygomatic
frontal
sphenoid

Question 35

find a diagram and label the 7 bones of the orbits

Question 36

know how to take OM, OM 30, PA orbit and PA mandible

Question 37

find and label facial/skull bones, skull sutures