radiology Flashcards
What are the differences between the frankfort plane and the orbitomeatal line?
FP = lower border of orbit-EAM
OM = outer canthus of eye - EAM
about 10 degrees out
What are the indications for taking a lateral skull?
BoS #
AP displacement of facial fracture
skull pathology (Pagets)
What view would you take for maxillofacial view - PA or AP?
why?
PA - posterioanterior
(anterior (face) is closer to film, less magnified, low energy photons attenuated before reaching most radiosensitive tissues)
what is the difference between an OM 0 and OM30?
patient positioned the same
the angle of the x-ray head to the plat changes
list some interactions for OM radiographs
mid 1/3 facial fractures (zygoma, le fort)
coronoid process fractre
but largely being replaced by CBCT
When is a PA mandible indicated?
angle, post bosy, ramus of mandible (med/lat displacement)
cysts or tumours
facial deformity
what are indications for CBCT?
implant planning impacted teeth pathology orthognathic surgery hypodontia CLP dental abnormalities
Midline maxillary radiolucency
well defined
corticated
not associated with apices of 11/21 - PDL space is clear.
what is it?
nasopalatine cyst
multiple mandibular radiolucencies in mixed dentition
all assocated with crowns of unerupted teeth. some are deeper, some are superficial.
what are they?
deeper ones are dentigerous cysts and need excision if they delay eruption
superficial ones are eruption cysts and need marsupialisation
madibular radiolucency below the IAN canal, what is it?
as below canal cannot be odontogenic in origin
must be stafnes cavvity
why is swelling in the palate concerning?
if there is odontogenic pathology of the max teeth, it causes buccal swelling.
palatal can be more sinister and from parotid
Pa radiolucency after tooth has had RCT. well defined radiopaque margin. what is it?
periapical granuloma
healing infection from before RCT
large, oval distal radiolucency in RHS mandible. well defined margin corticated salloped destruction of ID canal
ameloblastoma - destruction suggests aggressive
think odontogenic tumour
what is an ameloblastoma like radiographically?
radiolucent benign multilocular (uni variant) 30-50ys will recur if not fully removed slow growing locally destructive
what is an ameloblastoma like histologically?
infiltrative growth (not expansive)
no fibrous capsule
islands with single layer of columnar epithelium
stellate reticulum
if there is a radioluncency around the cron of a tooth, wahat could it be?
dentigerous cyst
adenomatoid odontogenic tumour (ant max, and has patchy calcification)
calcifying epithelial odontogenic tumour (further up tooth than dentigerous cyst, very displaced tooth)
how does an odonttogenic myxoma appear?
benign, multilocular soap bubble radiolucency
locally destructive as no capsule
bucco-lingual expansion
gelatinous tissue
What are some developmental abnormalities of bone?
- osteogenesis imperfecta
- achondroplasia
- osteopetrosis
- cherubism
if a patient presenst with slow growing, asymtomatic bony swelling and precocious puberty - what would you diagnose?
albrights syndrome
What are some inflammatory bone diseases?
alveolar osteitis osteomyelitis actinomycosis periositis MRONJ ORNJ
What are some giant cell lesions of the jaws and what are some differentials for them?
peripheral giant cell epulis
central giant cell granuloma
differnetial
- osteitis fibrosa cystica
- aneurysmal bone cyst
What is the pattern for pagets?
M >40
active increased bone turnover, but burns out
What are some different cementum lesions?
cementoblastoma (attached to root)
cemento osseous dysplasias (radiolucency which calcifies)
what are you likely to see with a radicular cyst?
commonly sequel to pulpitis/Pa granuloma
well defined radiolucency around apex
continuous with lamina dura
Bx of FNA shows neutrophils, cholestrol clefts,rushton bodies
what would you experience with an odontogenic keratocyst?
angle of mand, PA expansion no clinical symptoms well defined thin keratin - no rete pegs satellite cells in wall cell nests contains creamy semi solid material
can be related to gorlin goltz
