Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BDS4 > CDS Radiology > Flashcards

CDS Radiology Flashcards

1
Q

Skull radiographs

A

Group of radiographs used primarily for assessing maxillofacial trauma (face and jaws)
Sometimes used to assess diseases of the skull but quite limited in giving clear images of anatomy so most are supplanted with CT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Main types of skull radiograph

A

Occipitomental
Postero-anterior mandible
Reverse Towne’s
True lateral skull (v similar to lateral cephalogram except positioning not standardised with a cephalostat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Difference between a lateral cephalogram and a true lateral skull radiograph

A

In true lateral skull the patient position is not standardised with a cephalostat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Main use of skull radiographs

A

Assessing skull and jaw for trauma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Primary use of occipitomental radiograph

A

Fractures of the midface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Primary use of postero-anterior mandible radiographs

A

Primarily for fractures of posterior mandible (excluding condyles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Primary use of reverse Towne’s radiographs

A

Primarily for fractures of the mandibular condyles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the difference between occipitomental, postero-anterior mandible and reverse townes?

A

Fairly similar structures shown with slightly different angulations, meaning some structures are shown more clearly, and others obscured by anatomy getting in the way

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do you choose a type of skull radiograph?

A

Depending on what you are trying to look for
Occipitomental - midface
Postero-anterior mandible - posterior mandible (except condyles)
Reverse Townes - condyles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Skull Xray machine

A

Typically a specialised skull unit
Can be positioned to capture from different angles without pt having to move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Skull Xray receptor

A

Digital and large enough to capture relevant areas such as the entire head including jaws

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why is it so valuable that the skull Xray machine is flexible to different patient positions?

A

Pt can be erect or supine
Pt may be unconscious from head trauma
Pt may be drunk
Pt may have had a spinal injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Pt position for occipitomental radiograph

A

Face against the receptor with nose and chin touching it, keeping a specific angle
Xray beam from behind through the back of the head, through the face and to the receptor
Machine can also be rotated to recreate this position lying down if necessary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is patient positioning important in skull radiographs?

A

Anatomy would otherwise be distorted or obscured and we will not get the information we need

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Frankfort plane

A

Inferior border of the orbit to the superior margin of the external auditory meatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Orbitomeatal line

A

Outer canthus of the eye to the centre of the external auditory meatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Use of frankfort plane

A

Panoramic radiographs and lateral cephalograms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When is orbitomeatal line used?

A

Patient positioning for most skull radiographs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is this patient positioned for?

A

Occipitomental radiograph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Name A B C

A

A - Frankfort horizontal plane
B - Orbitomeatal line
C - Ala-tragus line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the most common radiograph used in facial trauma imaging?

A

Occipitomental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Middle third of the face

A

Top of orbit to maxillary teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What must we try to avoid when taking occipitomental radiograph for middle third facial trauma?

A

Superimposition of the skull base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Why are occipitomental radiographs often taken in pairs?

A

They can be taken at different angles (0, 10, 20, 30, 40 degrees)
Typically use two angles that aren’t too similar (e.g. 10 and 40) to view the bones at 2 different angles increasing the chance of spotting a fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Le Fort

A

Common fracture pattern when theres major trauma to the midface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Types of middle third fractures

A

Le fort I, II and III
Zygomatic complex (including arch)
Naso-ethmoidal comples
Orbital blow out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Orbital blow out fractures

A

Pressure in the eye due to a punch or elbow or similar blow, causes the orbital contents to fracture the floor or one of the walls of the orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Xray beam position for a 0 degree occipitomental radiograph

A

Perpendicular to the Xray receptor
Centred through occiput

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Xray beam position for an 30 degree occipitomental radiograph

A

30 degrees above a perpendicular line to the xray receptor
Centred through lower border of the orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the main difference when changing the angulation for an occipitomental radiograph?

A

Higher angulation moves the skull base slightly lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Why is it important to assess the zygomatic arch after trauma?

A

Quite exposed
Multiple areas susceptible to fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Occipitomental radiographs to view mandible

A

Unsuitable
Mandible is not seen clearly on OM radiographs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Why are Postero-anterior mandible radiographs unsuitable for viewing facial skeleton?

A

Superimposition of the base of the skull and nasal bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Indications for poster-anterior mandible radiographs

A

Lesions (to note medio-lateral expansion) and fractures involving
- Posterior third of body of mandible
- Angles
- Rami
- Low condylar necks
Mandibular hypoplasia/hyperplasia
Maxillofacial deformities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Patient position for postero-anterior mandible radiograph

A

Face towards receptor
Head tipped forward so that orbitomeatal line is perpendicular to the receptor (parallel to floor if pt standing)
Forehead nose position
Xray beam perpendicular to receptor and centred through cervical spine at level of rami

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why is the xray beam projected from posterior in skull radiographs?

A

Reduced magnification of the face as it is closer to the receptor so there is less room for the beam to diverge
Not much at the back of the head that is sensitive to radiation so reduced effective dose to radiosensitive tissues such as lens of the eye due to attenuation by the back of the skull

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the patient positioned for 1 and 2?

A

1 - OM radiograph 0 degrees
2 - OM radiograph 30 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q
A

Occipitomental radiograph 0-10 degree angulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q
A

Occipitomental radiograph 30-40 degree angulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Least common used skull radiograph

A

Reverse Townes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What type of radiograph is this?

A

Postero-anterior mandible radiograph

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

When is a reverse townes radiograph taken?

A

When fracture of condylar heads or necks is suspected or maybe abnormality such as hypoplasia or hyperplasia of the condyles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the main difference between postero-anterior mandible and reverse townes radiographs?

A

Reverse townes the mouth is open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Pt position for reverse townes radiograph

A

Face towards receptor
Head tipped forward so that orbitomeatal line is perpendicular to receptor (& parallel to floor if pt standing)
Forehead nose position
Mouth open
Xray beam 30 degrees below perpendicular to receptor and centred through the condyles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Why is mouth open for reverse townes radiographs?

A

To move the condylar heads out of the glenoid fossae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Why is the xray beam angled upwards for reverse townes radiographs?

A

For more easy visualisation of the condyles and less superimposition of the temporal bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

A

A

Coronal suture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

B

A

Frontal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

C

A

Greater wing of sphenoid bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

D

A

Nasal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

D

A

Nasal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

D

A

Nasal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

E

A

Zygomatic bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

K

A

Mastoid process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

F

A

Maxilla

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

G

A

Mandible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

H

A

Mental foramen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

I

A

Zygomatico-temporal suture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

J

A

Squamous temporal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

M

A

Occipital bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

N

A

Lambdoid suture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

O

A

Parietal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

L

A

External auditory meatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

A

A

Mastoid air cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

B

A

Lambdoid suture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

C

A

Odontoid process/dens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

D

A

C1 atlas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

E

A

C2 atlas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

F

A

Pituitary fossa/sella turcica

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

G

A

Sphenoid sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

H

A

Orbit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

I

A

Maxillary sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

J

A

Pterygo-mandibular fissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

A

A

Fronto-nasal suture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

B

A

Superior orbital fissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

C

A

Inferior orbital fissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

D

A

Inferior concha/turbinate bone

78
Q

E

A

Median maxillary suture

79
Q

F

A

Mental foramen

80
Q

G

A

Frontal bone

81
Q

H

A

Coronal suture

82
Q

I

A

Supra-orbital foramen

83
Q

J

A

Infra-orbital foramen

84
Q

K

A

Zygomatic bone

85
Q

L

A

Ramus

86
Q

A

A

Maxillary sinus

87
Q

B

A

Ramus

88
Q

C

A

Inferior concha/turbinate bone

89
Q

D

A

Frontal sinus

90
Q

E

A

Ethmoid air cells

91
Q

A

A

Nasolacrimal duct opening

92
Q

B

A

Infra-orbital foramen

93
Q

C

A

Condylar head

94
Q

D

A

Coronoid process

95
Q

E

A

Frontal bone

96
Q

F

A

Supra-orbital foramen

97
Q

G

A

Zygomatic bone

98
Q

H

A

Mastoid process

99
Q

A

A

Crista galli

100
Q

B

A

Foramen rotundum

101
Q

C

A

Condylar head

102
Q

D

A

Angle of the mandible

103
Q

E

A

Frontal sinus

104
Q

F

A

Orbit

105
Q

G

A

Superior orbital fissure

106
Q

H

A

Lateral wall of the maxillary sinus

107
Q

I

A

Odontoid process/dens of C2

108
Q

What view is this?

A

Occipitomental

109
Q

What view is this?

A

PA mandible

110
Q

What does PA mandible view look like?

A

Patient facing towards you straight on

111
Q

What does occipitomental view look like?

A

You are looking up the patients nose

112
Q

What are PA mandible radiographs used to look at?

A

The posterior mandible

113
Q

What are occipitomental skull radiographs used to assess?

A

Trauma to the midface

114
Q

What line is used to position a patient for a panoramic?

A

Frankfort plane

115
Q

What line is used in patient positioning for skull radiographs?

A

Orbitomeatal

116
Q
A

Orbitomeatal line

117
Q

Angulations for occipitomental radiographs

A

0-40 degrees

118
Q

What type of radiograph is the patient positioned for?

A

Occipitomental

119
Q

What type of radiograph is the patient positioned for?

A

PA mandible

120
Q

What type of radiograph is the patient positioned for?

A

Reverse Townes

121
Q
A

Periapical radiolucency associated with 41
Small lesion likely to be periapical granuloma - infection starting in the area

122
Q
A

21 22 ULC
Abnormal root morphology - root resorption
Dens in dente 22
Periapical radiolucency 22 well defined borders

123
Q
A

Radiopaque area distal to 15
Well defined margins
Radiolucent margin around the radiopacity
Probably odontome

124
Q
A

Bone loss between 11 and 12 ~30%
Calculus in cervical region of 12 and 13
Maxillary sinus and nasal cavity meet at Y of ennis visible
Radiolucency mesial to 14 - vertical bone loss extending to the apex

125
Q

What is the Y of Ennis?

A

Not a true anatomical landmark but seen only on radiographs due to superimposition of the floor of the nasal cavity (straight radiopaque line) and the border of the maxillary sinus (curved radiopaque line)

126
Q

What is this anatomical landmark called, and what is it caused by?

A

Y of Ennis
Caused by the superimposition of the inferior border of the nasal cavity on the medial border of the maxillary sinus

127
Q
A

Large radiolucent lesion spanning almost the entire width and heigh of the ramus of the mandible, unilocular, no resorption of the teeth, 48 being pushed down
Well defined margins
Turned out to be a tumour

128
Q

Why is the orbitomeatal line used to position patients for occipitomental radiographs?

A

So that the skull base does not obscure your desired view

129
Q

IRMER

A

Ionising radiation medical exposure regulations

130
Q

Rank these from highest effective radiation dose to lowest
CBCT scan of all teeth
Panoramic radiograph of full dentition
Full mouth periapicals
CT scan of all teeth

A

CT scan of all teeth
CBCT scan of all teeth
Full mouth periapicals
Panoramic radiograph of full dentition

131
Q

Why is cbct so useful?

A

You get all the information of a CT but with a lower dose
Very useful to look within the tissues without superimposition of other anatomy, which happens with plain radiographs.

132
Q
A

Provisional diagnosis for the abnormal radiopacity - condensing osteitis/sclerosing osteitis
Distal root has been resorbed
Well defined radiopacity
PDL space separates the root from the radiopacity
Grossly carious tooth

133
Q

What is CBCT?

A

Cone beam computed tomography
A form of cross-sectional imaging suitable for assessing radiodense structures, allowing you to take slices of image
Very useful to look within the tissues without superimposition of other anatomy, which happens with plain radiographs

134
Q

Examples of non dental and maxillofacial radiology uses for CBCT

A

Temporal bone imaging
Paranasal sinus imaging
Orthopaedic imaging
Radiotherapy planning

135
Q

Basic principle of CBCT

A

Ionising radiation
Conical/pyramidal Xray beam and square digital detector rotate around the head - no more than one full rotation
Captures many 2 dimensional images, potentially up to 200

136
Q

Patient position for CBCT

A

Unit specific
Usually standing or sitting, rarely supine
Head position typically the same as panoramic
- Frankfort plane horizontal and midsagittal plane vertical

137
Q

Benefits of CBCT over plain radiography

A

No superimposition
Ability to view subject from any angle
No magnification/distortion
Allows for volumetric (3D) reconstruction

138
Q

Downsides of CBCT over plain radiography

A

Increased radiation dose to patient
Lower spatial resolution (not as sharp)
Susceptible to artefacts
Equipment more expensive - initial, running and maintenance
Images more complicated to manipulate and interpret
Requires additional training - to justify, operate and interpret

139
Q

Benefits of CBCT over conventional CT

A

Lower radiation dose
Potential for sharper images - higher resolution
Cheaper - initial, running and maintenance
Smaller machine

140
Q

Benefits of CT over CBCT

A

Able to differentiate soft tissues better
“cleaner” images (less fuzziness)
Larger field of view possible

141
Q

Common used for CBCT in dentistry

A
  • Clarifying relationship between impacted mandibular third molar and inferior alveolar canal prior to intervention - after plain radiograph has suggested a close relationship.
    • Measuring alveolar bone dimension to help plan implant placement.
    • Visualising complex root canal morphology to aid endodontic treatment.
    • Investigating external root resorption next to impacted teeth - if not clear on plain radiographs.
    • Assessing large cystic jaw lesions and their involvement of important anatomical structures
142
Q

Common ways to view CBCT

A

From above or below
Sagittal view
Coronal view (straight on)

143
Q

Uses for CBCT 3D volume reconstruction

A

May help clinician picture the extent/shape of disease
Can be an informative teaching aid for the patient

144
Q

Issues with CBCT 3D volume reconstruction

A

It is a modified reconstruction of the data and so can create misleading images - particularly poor at showing thin bone

145
Q

When are the imaging factors for CBCT set?

A

Before the scan starts

146
Q

What will altering CBCT imaging factors impact?

A

The information obtained and the patient dose

147
Q

Settings for imaging factors for CBCT

A

Should be considered on a case-by-case basis using ALARP principle

148
Q

Imaging factors for CBCT

A

Field of view
Voxel size
Acquisition time (e.g. 10 seconds)

149
Q

Field of view for CBCT

A

The size of the captured volume of data
Decision based on the clinical case
Increased size = increased radiation dose + increased number of tissues irradiated +increased scatter (+more to report)

150
Q

Voxel size for CBCT

A

Image resolution
Voxel = 3D pixel
Never as small as intraoral radiograph pixels
Decision based on the clinical case
- Decreased voxel size increases radiation dose
- Decreased voxel size increases scan time (risk of pt moving)
- Decreased voxel size increases the amount of data, longer to process and more space to store

151
Q

Typical range of option for voxel size for CBCT

A

0.4mm^3 - 0.085mm^3

152
Q

When would large voxel size be used in CBCT?

A

When good resolution is not required, for example when needing to find out where an implant is

153
Q

When would small voxel size be used for CBCT?

A

When good resolution is required for looking at subtle details for example when looking at root canals for endo

154
Q

Imaging factor choices for CBCT for an endo case

A

Smallest FoV possible (unless large apical pathology)
Smaller voxel size to see the fine detail of the root canals

155
Q

Imaging factor choice for CBCT for implant planning cases

A

FOV depends on number/position of implants
Larger voxel size - often just looking at thickness of bone, or how close the alveolar crest is to IAN canal, no fine details needed

156
Q

Approximate effective doses for maxillofacial imaging

A
  • CBCT - 13-82 uSv
  • CT - 474-1160 uSv
  • Panoramic 3-24 uSv
  • Intraoral - 4 uSv
157
Q

How does dento-alveolar CBCT radiation dose compare to a panoramic?

A

CBCT ~ 2-3x the dose of a panoramic radiograph

158
Q

Artefacts in CBCT definition and two main types

A

Visualised structures on the scan that were not present in the object investigate
Most types can be avoided/reduced
Movement artefacts and streak artefacts

159
Q

Movement artefact CBCT

A

Occurs if patient not completely still during the full exposure - affects the whole scan
Can lead to general blurriness or extra contours
Typically reduced using fixation aids - chin rest, head strap etc.

160
Q

Streak artefacts in CBCT

A

Most notably caused by high attenuation objects
Primarily metals - e.g. amalgam, metal crowns or implants

161
Q

Main issues with streak artefacts

A

Can prevent caries assessment adjacent to restorations
Can prevent assessment of perforations/missed canals in root canal treated teeth

162
Q

Contraindications for CBCT

A

If plain radiographs are sufficient
Pathology requiring soft tissue visualisation such as malignancy or infection spreading in soft tissue
If high risk of debilitating artefacts - lots of metal restorations/fixed prostheses
Patient factors - pt unable to stay still e.g. Parkinsons, learning difficulties, uncooperative child, unable to fit into the machine

163
Q

Can GDPs refer for CBCT?

A

No

164
Q

Justification for CBCT

A

Must always be preceded by a clinical examination
CBCT can only be considered if plain radiography unable to provide sufficient information
Selection criteria - other guidance available to assist in justification from FGDP faculty of general dental practitioners

165
Q

Role of GDP in CBCT

A

Know the common situations where CBCT can aid patient management
Know its general limitations - not as sharp, movement/streak artefacts
Know that additional training is required to use CBCT

166
Q
A

Grossly carious UL8, distal caries UL7, periodontal bone loss, unusual appearance of sinus, retained roots with periapical radiolucencies, strange round slightly radiolucent area of bone - unusual presentation.

167
Q

What is considered a “jaw lesion”

A

Cysts
Benign neoplasms
Cancers
Developmental abnormalities
Reactive lesions
Genetic conditions

168
Q

What is the general appearance of majority of jaw lesions

A

Radiolucent

169
Q

Importance of correct diagnosis from radiographs

A

Indicate need/type of further investigation
To avoid unnecessary surgery
To prompt urgent management

170
Q

Three main groups of lesions on radiographs

A

Anatomical
Artefactual
Pathological

171
Q

7 factors of lesion description from radiographs

A
  1. Site
    1. Size
    2. Shape
    3. Margins
    4. Internal structure
    5. Effect on adjacent anatomy
    6. Number
172
Q

Description of site of radiographic lesion

A

Where is it? Alveolar bone vs basal bone
Jaws: anterior maxilla, maxillary tuberosity, mandibular body, condylar process, etc
Other: cervical spine, temporal bone, skull calvarium, etc.
Is there a notable relationship to another structure?
What is its position relative to particular structures?
e.g. inferior alveolar canal - lesions below are highly unlikely to be odontogenic
e.g. maxillary sinus floor - lesions entirely above are highly unlikely to be odontogenic

173
Q

Relevance of radiographic lesions relationship to the IAN canal

A

Lesions below it are highly unlikely to be odontogenic

174
Q

Relevance of radiographic lesions relationship to the maxillary sinus floor

A

Lesions entirely above are highly unlikely to be odontogenic

175
Q

Description of size of radiographic lesions

A

very useful as some types of lesions will only grow to a certain size
Measure (or estimate) dimensions OR describe the boundaries
Eg. 50mm mesiodistally by 35mm supero-inferiorly OR Extends between teeth 34 and 38, and from the alveolar crest to the inferior cortical margin of the mandible.
“3D” imaging such as CBCT allows for more accurate determination of size.

176
Q

Shape description of radiographic lesions

A

General
- Rounded
- Scalloped
- Irregular
“Locularity” - very important, particularly for radiolucencies, as some pathologies are ALWAYS multilocular and some other pathologies are NEVER multilocular.
- Unilocular
- Pseudolocular - appearance where only one bubble with slightly pinched in parts as if it is about to divide into locules. This can be because there are teeth pushing into it or because the bone has not expanded uniformly the whole way round.
- Multilocular - collection of bubbles

177
Q

Margins of radiographic lesion description

A

Margins - helpful because they can often give a good idea of the nature of the lesion - e.g. benign or malignant.
Descriptions
- Well defined and OR poorly defined and
- If well defined - Corticated/non corticated - white line around the edge=corticated
- If poorly defined - blending into the adjacent normal anatomy or “moth eaten” appearance

178
Q

Do corticated margins of a lesion suggest benign or malignant?

A

benign

179
Q

Does moth eaten margins of radiolucency suggest benign or malignant?

A

Malignant

180
Q

Internal structure of a radiolucency description

A

a. Entirely radiolucent
b. Radiolucent with some internal radiopacity
c. Radiopaque (homogenous or heterogenous)
Homogenous - uniformly radiopaque throughout

181
Q

Description of internal radiopacities in a radiolucency

A

Amount - scant, multiple, dispersed, etc
Bony septae - thin/coarse, prominent/faint, straight/curved
Particular structure - enamel and dentine radiodensity

182
Q

What makes jaw lesions radiolucent?

A
  • Resorption of bone
  • Decreased mineralisation of bone
  • Decreased thickness of bone
  • Replacement of bone with abnormal, less mineralised tissue
183
Q

What makes jaw lesions radiopaque?

A
  • Increased thickness of bone
  • Osteosclerosis of bone
  • Presence of abnormal tissues
  • Mineralisation of normally non mineralised tissues
184
Q

Pt positioning for occlusal radiographs

A

Ala tragus and maxillary plane parallel with floor

185
Q

Angulation and position of xray beam for upper occlusal

A

Approx 60 downwards depending on the inclination of the upper incisors
Proclined - increase vertical angulation
Retroclined - decrease
Just above bridge of the nose 1cm above ala tragus line

186
Q

Nerve passing through incisive fossa

A

Nasopalatine nerve

187
Q

Width of incisive fossa

A

3-6mm

188
Q

Incisive fossa appears >6mm what would you suspect?

A

Nasopalatine duct cyst

189
Q

How is aspirational biopsy done?

A

Wide bore needle
5-10ml syringe
Aspirate the clear straw coloured fluid (inflammatory or developmental)

190
Q

What would an aspirational biopsy of cream/white semi solid material suggest?

A

Orthokeratocyst

191
Q
A

BDS4 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions