Skull Radiographic Views & Anatomy Flashcards
What are ‘skull radiographs’?
group of plain radiographs used primarily for assessing maxillofacial trauma
What are the main types of skull radiographs?
- occipitomental
- postero-anterior mandible
- reverse Towne’s
- true lateral skull
What radiograph is a true lateral skull similar to? How do they differ?
Similar to a Lateral Cephalogram
- true lateral skull positioning is not standardised with a cephalostat
What is a occipitomental radiograph typically used for?
assessing fractures of the midface
What is a postero-anterior mandible radiograph typically used for?
assessing fractures of posterior mandible (excluding condyles)
What is a Reverse Towne’s radiograph typically used for?
assessing fractures of mandibular condyles
Why are skull radiographs not typically taken in general dental practise?
Need specialist equipment (specialised skull unit)
How can the receptor for skull radiographs be described?
digital & large enough to capture relevant areas (eg entire head including jaws)
What reference line is used in patient positioning for most skull radiographs?
Orbitomeatal line
What are the landmarks of the orbitomeatal line?
- outer canthus of eye
- centre of external auditory meatus
Why is it essential that skull radiographs are aligned with the orbitomeatal line?
So the radiographs are not distorted by other anatomy
What is shown on an occipitomental (OM) radiograph?
Facial skeleton, avoiding superimposition of skull base
What angles can occipitomental radiographs be taken at??
- 0 degrees
- 10 degrees
- 30 degrees
- 40 degrees
If you were evaulating facial trauma with an occipitomental radiograph, what views would you perhaps use?
10 degrees & 40 degrees toegther (2 radiographs)
What are some indications for taking an occipitomental radiograph?
Middle third fractures
- Le Fort I, II & III
- Zygomatic complex (including arch)
- Naso-ethmoidal complex
- Orbital blow-out
Coronoid process fractures
Describe the patient positioning for an occipitomental radiograph?
- face towards receptor
- head tipped back: obitomeatal line at 45 degrees to receptor
- roughly a nose-chin position
If a patient was standing for an occipitomental radiograph, what angle would the orbitomeatal line be to the floor?
45 degrees to floor
Where is the x-ray beam positioned in a 0 degree occipitomental radiograph in relation to the receptor?
perpendicular to receptor & centred through occiput
Where is the x-ray beam positioned in a 30 degree occipitomental radiograph in relation to the receptor?
30 degrees above perpendicular line to receptor & centred through lower border of orbit
What skull radiograph would NOT be appropriate for viewing the facial skeleton? why?
Postero-anterior mandible radiograph
- superimposition of base of skull & nasal bones
What is shown on a postero-anterior mandible radiograph?
posterior parts of mandible
What are some indications for taking a postero-anterior mandible radiograph?
Lesions & fractures involving:
- posterior third of body
- angles
- rami
- low condylar necks
- mandibular hypo/hyperplasia
- maxillofacial deformities
How is the patient positioned for a postero-anterior mandible radiograph?
- face towards receptor
- head tipped forward so that orbitomeatal line is perpendicular to receptor
- ‘forehead-nose’ position
How is the x-ray beam angulated for a postero-anterior mandible radiograph?
perpendicular to receptor & centred through cervical spine at level of rami
