Radiology Flashcards
what is a cyst
pathological cavity with fluid, semi-fluid or gaseous contents but not created by pus accumulation
give 4 inflammatory cysts
- radicular
- residual
- lateral radicular
- paradental
give 4 developmental cysts
- dentigenerous
- keratocyst
- eruption
- lateral periodontal cyst
give 3 non-odontogenic cysts
- nasopalatine duct cyst
- solitary bone cyst
- aneurysmal bone cyst
enucleation - adv and disadv
complete removal of the cyst and epithelial lining
ADV - full removal, pathological examination, primary closure, little aftercare
DISADV - risk mandibular fracture, structure damage, not for old/ill-health, infection, risk of recurrence
marsupialisation - adv and disadv
creation of surgical window, removal of cyst contents and suturing of cyst wall to surrounding epithelium to encourage decrease in size and lateral enucleation
ADV - simple, may spare vital structures
DISADV - not definitive, recurrence, complete lining not available for histopathology, hard to keep clean, lots of aftercare, two-stage
KCOT - odontogenic keratocyst
where does it develop from
RESTS OF SERRES
- remnants of dental lamina
how does keratocyst appear histologically
- thin Strat squamous, parakeratosis, no inflammatory
- basal cell nuclei palisading, daughter cells
how does odontogenic keratocyst appear radiographically
scalloped margins, 25% multilocular
well-defined, mandible
teeth displacement
medial-distal expansion first
why is odontogenic keratocyst problematic
VERY HIGH rate of recurrence
due to thin friable lining, hard surgery, daughter cells tearing and proliferating
what condition is odontogenic keratocyst associated with
Basel Cell Naeuvs, Gorlin Goltz
where does radicular cyst develop from
RESTS OF MALASSEZ
remnants of Hertwig’s epithelium root sheath
inflammatory
how does radicular cyst appear histologically
incomplete epithelial lining, connective tissue capsule with inflammation, non-keratinised strat squam, inflammatory infiltrate
how does radicular cyst appear radiographically
corticated margins continuous with lamina dura of NONVITAL tooth
well-defined, round/oval, may displace
what does dentigerous cyst develop from
reduced enamel epithelial, remnants of enamel organ
developmental
associated with PE/impacted tooth
how does dentigerous cyst appear histologically
thin non strat squamous, cuboidal cells, compression and fibrous connective tissue between crown and follicle
how does dentigerous cyst appear radiographically
associated with crown of unerupted/impacted tooth, cystic change
corticated margins attached to CEJ, may envelope root or displace
where is a dentigerous cyst normally seen
lower 8’s, upper 3’s
name 1 epithelial derived odontogenic tumour
ameloblastoma
what is the histology of ameloblastoma
cystic changes, palisaded basal layer, stellate reticulum-like central cells
name 1 mesenchyme tumour
odontogenic myxoma
name 1 mixed epithelium and mesenchyme tumour
odontoma
give 2 developmental bone pathologies
achondroplasia, torus, osteogenesis imperfecta
give 2 inflammatory bone pathology
alveolar osteitis, condensing osteitis, osteomyelitis
give 2 neoplasm bone pathology
osteosarcoma, osteoma
give 2 metabolic bone pathology
rickets, hyperparathyroidism, osteoporosis, Paget’s
give 4 differential diagnoses for multilocular radiolucency
keratocyst
ameloblastoma
central giant cell granuloma
odontogenic myxoma
why would the anterior teeth appear distorted in an OPT
pt positioned too far forward or too far back in the machine
why would there be a blurry image produced by an OPT
pt moved while image was being taken
how can OPT positioning error be limited
- pt instructed to stay as still as possible
- adjunts; bite block between incisors, hand rails, correct height
- ensure right set up of laser lines before taking image, Frankfort plane parallel to the floor
- correct machine settings
give 3 characteristics of a ghost image
- magnified
- blurry
- transposed to other side
- higher
give 3 ways to reduce pt dose
- rectangular collimation [reduced scatter and unnecessary exposure]
- reduce exposure parameters
- lead diaphragm at end of spacer cone
Compton vs photoelectric effect
compton - xrayphoton interacts with outer shell election, ejecting it + photon deflected, contributes to scatter radiation
photoelectric - xray photon completely absorbed when knocks out inner electron, creation of photoelectron and produces characteristics X-ray
what metal is used for absorption in X-rays
lead
name metals used in the X-ray tube head
tungsten target
copper heat dissipation
what is ALARP and how is it achieved
as low as reasonable practicable
selection criteria, optimisation, protection measures
