Radiology

Question 1

what is a cyst

Answer 1

pathological cavity with fluid, semi-fluid or gaseous contents but not created by pus accumulation

Question 2

give 4 inflammatory cysts

Answer 2

• radicular
• residual
• lateral radicular
• paradental

Question 3

give 4 developmental cysts

Answer 3

• dentigenerous
• keratocyst
• eruption
• lateral periodontal cyst

Question 4

give 3 non-odontogenic cysts

Answer 4

• nasopalatine duct cyst
• solitary bone cyst
• aneurysmal bone cyst

Question 5

enucleation - adv and disadv

Answer 5

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

Question 6

marsupialisation - adv and disadv

Answer 6

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

Question 7

KCOT - odontogenic keratocyst
where does it develop from

Answer 7

RESTS OF SERRES
- remnants of dental lamina

Question 8

how does keratocyst appear histologically

Answer 8

• thin Strat squamous, parakeratosis, no inflammatory
• basal cell nuclei palisading, daughter cells

Question 9

how does odontogenic keratocyst appear radiographically

Answer 9

scalloped margins, 25% multilocular
well-defined, mandible
teeth displacement
medial-distal expansion first

Question 10

why is odontogenic keratocyst problematic

Answer 10

VERY HIGH rate of recurrence
due to thin friable lining, hard surgery, daughter cells tearing and proliferating

Question 11

what condition is odontogenic keratocyst associated with

Answer 11

Basel Cell Naeuvs, Gorlin Goltz

Question 12

where does radicular cyst develop from

Answer 12

RESTS OF MALASSEZ
remnants of Hertwig’s epithelium root sheath

inflammatory

Question 13

how does radicular cyst appear histologically

Answer 13

incomplete epithelial lining, connective tissue capsule with inflammation, non-keratinised strat squam, inflammatory infiltrate

Question 14

how does radicular cyst appear radiographically

Answer 14

corticated margins continuous with lamina dura of NONVITAL tooth
well-defined, round/oval, may displace

Question 15

what does dentigerous cyst develop from

Answer 15

reduced enamel epithelial, remnants of enamel organ

developmental
associated with PE/impacted tooth

Question 16

how does dentigerous cyst appear histologically

Answer 16

thin non strat squamous, cuboidal cells, compression and fibrous connective tissue between crown and follicle

Question 17

how does dentigerous cyst appear radiographically

Answer 17

associated with crown of unerupted/impacted tooth, cystic change
corticated margins attached to CEJ, may envelope root or displace

Question 18

where is a dentigerous cyst normally seen

Answer 18

lower 8’s, upper 3’s

Question 19

name 1 epithelial derived odontogenic tumour

Answer 19

ameloblastoma

Question 20

what is the histology of ameloblastoma

Answer 20

cystic changes, palisaded basal layer, stellate reticulum-like central cells

Question 21

name 1 mesenchyme tumour

Answer 21

odontogenic myxoma

Question 22

name 1 mixed epithelium and mesenchyme tumour

Answer 22

odontoma

Question 23

give 2 developmental bone pathologies

Answer 23

achondroplasia, torus, osteogenesis imperfecta

Question 24

give 2 inflammatory bone pathology

Answer 24

alveolar osteitis, condensing osteitis, osteomyelitis

Question 25

give 2 neoplasm bone pathology

Answer 25

osteosarcoma, osteoma

Question 26

give 2 metabolic bone pathology

Answer 26

rickets, hyperparathyroidism, osteoporosis, Paget's

Question 27

give 4 differential diagnoses for multilocular radiolucency

Answer 27

keratocyst ameloblastoma central giant cell granuloma odontogenic myxoma

Question 28

why would the anterior teeth appear distorted in an OPT

Answer 28

pt positioned too far forward or too far back in the machine

Question 29

why would there be a blurry image produced by an OPT

Answer 29

pt moved while image was being taken

Question 30

how can OPT positioning error be limited

Answer 30

- 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

Question 31

give 3 characteristics of a ghost image

Answer 31

- magnified - blurry - transposed to other side - higher

Question 32

give 3 ways to reduce pt dose

Answer 32

- rectangular collimation [reduced scatter and unnecessary exposure] - reduce exposure parameters - lead diaphragm at end of spacer cone

Question 33

Compton vs photoelectric effect

Answer 33

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

Question 34

what metal is used for absorption in X-rays

Answer 34

lead

Question 35

name metals used in the X-ray tube head

Answer 35

tungsten target copper heat dissipation

Question 36

what is ALARP and how is it achieved

Answer 36

as low as reasonable practicable selection criteria, optimisation, protection measures