Skull Radiographic Views & Anatomy

Question 1

what are skull radiographs mainly for?

Answer 1

assessing maxillofacial trauma

Question 2

What are main types of skull radiographs?

Answer 2

• Occipitomental
• Postero-anterior mandible
• Reverse Towne’s
• True lateral skull

Question 3

what is this and what is used for?

Answer 3

occipitomental and primary for fractures of midface

Question 4

what is this and what is used for?

Answer 4

Primarily for fractures of posterior mandible (excluding condyles)

Question 5

what is this and what is used for?

Answer 5

Primarily for fractures of mandibular condyles

Question 6

how do you position equipment for skull radiographs?

Answer 6

• can be positioned so pt doesn’t need to move
• Patient can be standing up (“erect”) or lying on
  back (“supine”)
• Valuable in trauma imaging since patient may be
  unconscious/drunk/unable to move

Question 7

what is this?

Answer 7

orbiotmeatal line

Question 8

what is landmarks for orbitomeatal line?

Answer 8

• Outer canthus of eye
• Centre of external auditory meatus

Question 9

angles occiptomemntal radiographs? what used for?

Answer 9

Can be taken at different angles
* e.g. 0°, 10°, 30° or 40°
* Typically use two together to evaluate facial trauma
* e.g. 10° & 40°

• used for middle third facial fractures

Question 10

indications of occiptomental radiographs?

Answer 10

Middle third fractures
* Le Fort I, II & III
* Zygomatic complex (including arch)
* Naso-ethmoidal complex
* Orbital blow-out

Coronoid process fractures

Question 11

Answer 11

Question 12

what is Postero-anterior (PA) mandible radiograph not suitable for?

Answer 12

Not suitable for viewing facial skeleton because of
superimposition of base of skull & nasal bones

Question 13

indications for posterior anterior mandible radiographs?

Answer 13

Lesions (to note medio-lateral expansion),
& fractures involving:
* Posterior third of body
* Angles
* Rami
* Low condylar necks

Mandibular hypoplasia/hyperplasia

Maxillofacial deformities

Question 14

Why is X-ray beam projected from posterior side? for PA radiograph?

Answer 14

1. Reduced magnification of face (since closer to receptor)
   * Less distortion of relevant structures
   * Back of skull will be magnified more as a result but is less important
2. Reduced effective dose
   * X-ray beam partly attenuated by back of skull before reaching face
   * Lower radiation dose to radiosensitive tissues (e.g. lens of eye) as a result

Question 15

Answer 15

Question 16

indications for reverse townes radiograph and what is shows?

Answer 16

Shows condylar heads & necks

Indications
* High fractures of condylar necks
* Intracapsular fractures of TMJ
* Condylar hypoplasia/hyperplasia

Question 17

why do you have mout open for reverse townes?

Answer 17

• Moves condylar heads out of glenoid fossa