main points

Question 1

types of intraoral views

Answer 1

• bitewings
• periapicals
• occlusals

Question 2

types of extra oral views

Answer 2

• panoramics
• Cone Beam CT

Question 3

what is radiolucent and radiopaque

Answer 3

radiolucent: beam is less attenuated - appear darker
radiopaque: beam is more attenuated - appear lighter

Question 4

what bitewings are for

Answer 4

• interproximal caries of posterior
• alveolar bone level

Question 5

triangular radiolucency at CEJ

Answer 5

Cervical Burnout

Question 6

explain phenonmenon of cervical burnout

Answer 6

• radiolucent at CEJ
• increased X-ray penetration in the neck of the tooth due to its anatomical shape and decreased density

Question 7

radiopauqe zone under amalgam

Answer 7

due to Sn & Zn ions releasing into demineralised dentine

Question 8

whats Mach Band Effect

Answer 8

• optical illusion by retina
• bright areas look brighter, dark looks darker
• misleading

Question 9

caries appearance in dentine and enamel

Answer 9

enamel: triangular
dentine: fuzzy, ill-defined margin

Question 10

usage of PAs

Answer 10

• periapical pathology
• bone leves of single tooth

Question 11

types of upper and lower occlusal views

Answer 11

upper

• anterior oblique maxillary
• lateral oblique maxillary

lower

• true mandibular occlusal
• anterior oblique mandibular

Question 12

what type of view

Answer 12

anterior oblique maxillary

Question 13

what type of view

Answer 13

lateral oblique maxillary

Question 14

what type of view

Answer 14

true mandibular occlusal

Question 15

description of lesion

Answer 15

• site
• estimated size/ extent
• shape
• margins/ outine (corticated)
• surrounding structure and affect
• unilocular/ multilocular
• radiodensity

Question 16

curve of spee/ wilson

Answer 16

spee: occlusal curvature
wilson: curvature across arch curvature

Question 17

What does ALARP stand for

Answer 17

as low as reasonably practicable

Question 18

guidance on using x-ray safely

Answer 18

Faculty of General Dental Practice

Question 19

OPT full name

Answer 19

orthopantomogram

Question 20

whats tomography

Answer 20

slices of image - no overlapping

Question 21

OPT receptor and x-ray beam position

Answer 21

receptor in front
x-ray beam behind

Question 22

focal trough

Answer 22

• structure on it will appear clearly
• tomographic slice of interest
• thinner at the incisor region
• anything out of “normal” dental arch will be blurry

Question 23

OPT limitation/ contraindication/ disadvantages

Answer 23

• longer expoure time (Mobility eg parkinsons )
• ectopic tooth out of focal trough
• more superimposition/ artefacts
• worse clarity
• higher radioation dose (5x more than PA)
• anterior superimposed by cervical spine

Question 24

OPT advnatages

Answer 24

• capture full dentition
• capture non-dental areas (condyles /max sinus/ rami)
• no need of intra-oral holders (gaggers/ children/ trauma)

Question 25

how to adjust OPT for better view for interdental bone loss and IP caries?

Answer 25

Orthogonal program

Question 26

OPT - structure lingual/ buccal to focal trough magnified more?

Answer 26

Lingual

- as x-ray beam is from behind ot (lingual)
- more time under x-ray

Question 27

OPT - whats the verticl angulation of beam

Answer 27

• 8 degree above horizontal
• angled upwards

-to reduce superimposition of hard palate

Question 28

estimation of effective dose of each radiographic view

Answer 28

unit: Micro Sieverts

Question 29

OPT - how to reduce radiation dose

Answer 29

field limitatio eg half / mid face OPT

Question 30

OPT- what happen if pt chin down/ up

Answer 30

down: smiling occlusal plane
up: flat occlusal plane

Question 31

OPT - what happen if mid-sagittal plane not centred

Answer 31

distortion of one / both side

Question 32

OPT what happen if pt slumped

Answer 32

excessive cervial spine shadow

Question 33

OPT- what happem if pt stand too back/forward

Answer 33

Blurry (out of focal trough)
front : incisors appear narrower
back: incisors appear wider

Question 34

Ghost shadow appearance

Answer 34

• magnified
• blurry
• higher
• opposite side

Question 35

selection criteria is based on

Answer 35

selection criteria for dental radiography by the FGDP (Faculty of General Dental Practice UK)

Question 36

OPT selection criteria FGDP

Answer 36

only when presence of specific clinicla signs and symptoms - not routine screening

Question 37

some OPT indication

Answer 37

• generalised caries
• perio bone assess (not ideal anteriors)
• bony lesion (cyst )
• 3rd molar
• ortho assessment
• mandibular #
• max sinus pathology
• TMD
• pre-implant planning

Question 38

PA vs OPT

adv of each

Answer 38

Pa

• higher resolution
• greater for anterior
• capture in split second (less movement artefact)

OPT:

• more anatomical structure shown
• lower dose than full mouth PA
• no intra oral receptors (gagging)
• less time consuming

Question 39

bitewing vs OPT

adv of each

Answer 39

bw:

• higher resolution
• Good for IP caries (less overlapping)
• lower dose (if L+R)

OPT

• show periapical region

Question 40

what lateral ceph good for?

Answer 40

• relationship of jaws
• angulation of ant teeth
• ortho assessment

Question 41

CBCT advantages

Answer 41

• 3 D images
• looking at diff angles
• multiple slices

Question 42

possible pathology of pa radiolucency

Answer 42

1. Periapical Abscess
2. Periapical Granuloma
3. Radicular (Periapical) Cyst
4. Osteomyelitis
5. Traumatic Bone Cyst
6. Pulpal Necrosis

Question 43

possible causes of widening of PDL (w/o PA radiolucency)

Answer 43

• Occlusal Trauma
• Early Stage of Infection or Inflammation
• Orthodontic Movement treatment.
• Traumatic Injury
• Systemic Diseases