Radiology Flashcards
Topics covered: Cysts and Cyst-like Radiolucencies, Imaging of the TMJ, Imaging of Salivary Glands, Radiology of Other Pathologies, Radiographic Appearances of Malignancy in the Oral Cavity (285 cards)
1
Q
Why do most jaw lesions appear radiolucent?
A
As they have a reduced radiodensity compared to surrounding bone as a result of:
- Resorption of bone
- Decreased mineralisation of bone
- Decreased thickness of bone
2
Q
What is a cyst?
A
A pathological cavity having fluid, semi-fluid, or gaseous contents and which is NOT created by the accumulation of pus.
3
Q
Name 3 types of odontogenic developmental jaw cysts:
A
- Dentigerous cyst (and eruption cyst)
- Odontogenic Keratocyst
- Lateral periodontal cyst
4
Q
Name 2 types of odontogenic inflammatory jaw cysts:
A
- Radicular cysts
- Inflammatory collateral cysts
5
Q
What are the 3 types of radicular cyst?
A
Apical
Lateral
Residual
6
Q
What are the 2 types of inflammatory collateral cyst?
A
Paradental cyst and Buccal bifurcation cyst
7
Q
Name one type of non-odontogenic developmental jaw cyst:
A
Nasopalatine duct cyst
8
Q
Name 2 types of non-odontogenic cyst-like jaw lesions:
A
- Solitary bone cyst
- Stafnes idiopathic bone lesion
9
Q
How would you establish a differential diagnosis when looking at jaw cysts/cyst-like radiolucencies?
A
- Look at the radiograph and decide whether the radiolucency is:
- Anatomical
- Artifactual
- Pathological - If pathological nature describe the lesion:
- Site
- Size
- Shape
- Margins
- Internal structure
- Tooth involvement
- Effect on adjacent anatomy
- Number
10
Q
Name one jaw cyst that can occasionally occur bilaterally:
A
Paradental cyst
11
Q
Which syndrome might you suspect is a patient presents with multiple odontogenic keratocysts?
A
Multiple Basal Cell Naevoid Syndrome
12
Q
When might a cyst become poorly defined on a radiolucency?
A
If there is infection or malignancy
13
Q
What does a moth-eaten cyst-like radiolucency indicate?
A
Malignancy
14
Q
List 8 pathological causes for periapical radiolucency:
A
- Periapical granuloma
- Periapical abscess
- Radicular cyst
- “Perio-endo” lesion
- Cemento-osseous dysplasia (in early stages)
- Surgical defect (following peri-radicular surgery)
- Fibrous healing defect (following resolution of lesion)
- Ameloblastoma occurring next to a tooth
15
Q
How do radicular cysts form?
A
By chronic inflammation at the apex of the tooth due to pulp necrosis.
16
Q
Is a radicular cyst associated with a vital or non-vital tooth?
A
Non-vital tooth
17
Q
Is a radicular cyst most commonly seen in the maxilla or mandible?
A
Maxilla (60%)
18
Q
Following pulpal necrosis of the tooth, describe the pathological journey of the tooth:
A
Pulp necrosis > Periapical periodontitis > Periapical granuloma > Radicular cyst
19
Q
What is the clinical presentation of a radicular cyst?
A
- Often asymptomatic
- May become infected - resulting in pain
- Typically slow growing with limited expansion
20
Q
What is the radiographic presentation of a radicular cyst?
A
- Site - apex of a non-vital tooth
- Size - variable
- Shape - unilocular and rounded
- Margins - well defined and corticated
- Internal structure - entirely radiolucent
- Tooth involvement - yes associated with the root, margins continuous with lamina dura
- Effects - can displace adjacent teeth/structures, long-standing lesions can cause external root resorption
- Number - single (but potentially multiple if grossly carious dentition
21
Q
How do you differentiate a radicular cyst from a periapical granuloma?
A
- Difficult to differentiate radiographically
- Radicular cysts are typically larger
- If radiolucency diameter is >15mm - 2/3 cases will be a radicular cyst
22
Q
How do dentigerous cysts arise?
A
Arise when there is cystic change of the dental follicle.
23
Q
What are dentigerous cysts associated with?
A
The crown of an unerupted /impacted tooth - commonly mandibular third molars, maxillary canines
24
Q
Are dentigerous cysts most commonly seen in the maxilla or mandible?
A
Mandible
25
What is the radiographic presentation of a dentigerous cyst?
1. Site - around the crown of an unerupted tooth (often symmetrical encapsulation of crown but may expand unilaterally
2. Size - variable (e.g. can involve entire ramus of mandible)
3. Shape - unilocular and rounded but can be scalloped if large
4. Margins - well-defined and corticated
5. Internal structure - entirely radiolucent
6. Tooth involvement - yes, continuous with CEJ (but large cysts can begin to envelope the root as well)
7. Effects - displacement of the tooth, potential external root resorption of adjacent teeth, variable displacement of adjacent structures
8. Number - single
26
How do you differentiate a dentigerous cyst from an enlarged dental follicle?
1. Consider cyst if follicular space > or = 5mm
- Measure from surface of crown to edge of follicle
- Normal follicular space typically 2-3mm
- Assume cyst if >10mm
2. Consider cyst if radiolucency is asymmetrical
27
Are inflammatory collateral cysts associated with a vital tooth or a non-vital tooth?
Vital tooth
28
Where do buccal bifurcation cysts normally arise?
At the buccal aspect of the mandibular first molar
29
Where do paradental cysts normally arise?
Typically occurs at the distal aspect of a partially erupted mandibular third molar.
30
What is the typical radiographic presentation of an inflammatory collateral cyst?
1. Site - buccal or distal to furcation area of permanent molars (mandible > maxilla)
2. Size - <25mm
3. Shape - unilocular and rounded
4. Margins - well-defined and corticated
5. Internal structure - entirely radiolucent
6. Tooth involvement - yes, involves furcation
7. Effects - tilting of tooth, cortical displacement - buccal bifurcation cysts tend to tilt the crown of the tooth buccally
8. Number - single or bilateral
31
Which types of cysts/cyst like lesions tend to occur in younger patients? (1st and 2nd decades)
1. Inflammatory collateral cysts (paradental, buccal bifurcation)
2. Solitary bone cyst
3. Odontogenic Keratocysts
32
What direction do OKCs grow?
Anteroposteriorly
33
Are OKCs most commonly found in the mandible or the maxilla?
Mandible
34
Are OKCs most commonly found anteriorly or posteriorly?
Posteriorly
35
What is the typical radiographic presentation of OKCs?
* Site - commonly posterior mandible
* Size - variable but can get very large
* Shape - pseudolocular or multilocular, scalloped
* Margins - well defined and corticated
* Internal structure - entirely radiolucent
* Tooth involvement - no but often next to one
* Effects - marked expansion with trabecular bone in contrast to limited displacement of cortices, minimal displacement of adjacent teeth, rare external root resorption
* Number - single (but can be multiple if syndromic)
36
If multiple keratocysts are present, what condition should you consider?
Basal Cell Naevus Syndrome
**aka Gorlin-Goltz Syndrome or Bifid Ribs Syndrome
37
How does Basal Cell Naevus Syndrome normally present?
multiple OKCs, multiple basal cell carcinomas (skin), palmar and plantar pitting, calcification of intracranial dura mater etc
38
What is an ameloblastoma?
A locally destructive but slow progressing benign epithelial tumour
39
What direction do ameloblastomas grow in?
All directions - anteroposteriorly and buccal-lingually
40
Where do most ameloblastomas grow?
Posterior mandible
41
What is the typical radiographic appearance of an ameloblastoma?
* Site - commonly in the posterior mandible
* Size - any size
* Shape - unilocular or multilocular (multilocular lesions are more common and may have a coarse septae and/or "soap bubble appearance"
* Margins - well-defined and corticated
* Internal structure - radiolucent (but rare radiopaque variant)
* Tooth involvement - none
* Effects - can grow in all directions (not constrained by cortices) - thinning or cortices can cause 'knife edge' external root resorption
* Number - single
42
What is an odontogenic myxoma?
A benign mesenchymal odontogenic tumour
43
Where are odontogenic myxomas more commonly found?
Often in the mandible premolar/molar region
44
What is the typical radiographic appearance of an odontogenic myxoma?
* Site - often premolar/molar region of mandible
* Size - any size
* Shape - multilocular and scalloped
- May have coarse septae and/or soap bubble appearance
- Small lesions can be unilocular
* Margins - well-defined, thin corticated margin
* Internal structure - radiolucent
* Tooth involvement - none
* Effects - initially extends to the inter-radicular spaces but larger lesions displace teeth, initial expansion within trabecular bone before displacing cortices
* Number - single
45
What symptoms may the patient experience if they have a nasopalatine duct cyst?
A salty taste in their mouth
May have a slight palatal swelling
46
What is the typical radiographic appearance of a nasopalatine duct cyst?
* Site - always anterior maxilla in midline
* Size - usually between 6mm and 30mm in diameter
* Shape - typically unilocular, rounded and symmetrical but can be pseudolocular and lop sided, may appear heart-shaped due to superimposed anterior nasal spine
* Margins - well-defined and corticated
* Internal structure - entirely radiolucent
* Tooth involvement - no, but inevitably next to incisor roots
* Effects - displacement of incisors, palatal expansion
* Number - single
47
How would you differentiate a nasopalatine duct cyst from an incisive fossa?
The incisive fossa may or may not be visible on radiographs (midline, oval-shaped radiolucency, typically not visibly corticated on radiographs)
In the absence of clinical issues, consider the transverse diameter
- <6mm - assume incisive fossa
- 6-10mm - consider monitoring
- >10mm - suspect cyst
48
What is a solitary bone cyst?
Aon-odontogenic lesion - technically NOT classed as a cyst
Also known as simple/traumatic/haemorrhagic bone cyst
49
What can solitary bone cysts occur in association with>
Other bone pathology (e.g. fibro-osseous lesions)
50
What is the typical radiographic presentation of a solitary bone cyst?
* Site - typically posterior mandible
* Size - typically <30mm approximately
* Shape - unilocular or pseudolocular, scalloped - may extend into inter-radicular spaces with finger-like projections
* Margins - variable
* Internal structure - entirely radiolucent
* Tooth involvement - none (although may occur near teeth)
* Effects - typically none, rare displacement of teeth
* Number - single
51
What is a Stafne defect?
A depression in the bone (cortical bone preserved)
52
What does stafnes defect contain?
Salivary or fatty tissue
53
What is the typical radiographic presentation of stafne's defect?
* Site - mandible (often body but can be ramus)
* Size - usually <20mm
* Shape - unilocular and rounded
* Margins - well-defined and corticated
* Internal structure - entirely radiolucent
* Tooth involvement - none
* Effects - typically none, rare displacement of adjacent structures
* Number - single
54
How might a cyst appear differently in the presence of infection?
May lose its well-defined corticated margin
May appear malignant
55
How would a cyst appear radiographically in bone vs in the maxillary sinus?
The cyst would appear radiolucent in bone but radiopaque in the maxillary sinus
56
What anatomical structures make up the TMJ?
1. Bone:
- condylar head of the mandible
- articular eminence and the glenoid fossa of the temporal bone in the middle cranial fossa.
2. Muscles:
- specifically the muscles of mastication
3. Articular disc
4. Ligaments
5. Neurovascular structures
57
Which imaging modalities ca be used to assess the TMJ?
1. Plain film - OPT, PA Mandible, Reverse Townes, Lateral Obliques
2. Cone Beam CT
3. Computed tomography (CT)
4. Magnetic Resonance Imaging (MRI)
5. Nuclear Medicine
58
Is an OPT necessary for TMJ assessment?
Explain your answer.
FGDP states that in most cases an OPT is NOT necessary for the assessment of TMJ.
This is because most TMJ pain is myofascial in origin rather than bony or soft tissue in origin.
59
What view of the condylar head does an OPT give?
Lateral view
However position can vary depending on the pt positioning (e.g. large overjet - postural compensation)
60
What view of the condylar head does a PA mandible give?
Posteroanterior view
61
What view of the mandible does a Reverse Townes give?
AP view of the mandible
62
What view of the condylar head does a lateral oblique give?
Gives a lateral view of the condylar head
63
How might a CBCT be useful for assessing the the TMJ?
1. Allows visualisation of the TMJ in cross-section
2. Allows limitation of the FOV to just the condylar heads with the articular eminence - useful when looking for bony changes
3. Can be useful when assessing the TMJ of a pt that has had recent trauma that does not require immediate surgery
64
What is not very defined in a CBCT?
Soft tissue
65
Why are conventional CT's better for examining neoplastic masses than CBCT?
As conventional CT's allow the visualisation of both soft tissue and bone whereas CBCTs only allow visualisation of bone.
66
Do conventional CT's have better resolution than CBCTs?
It depends on the voxel size
Typically CBCTs have a smaller voxel size than CTs
However, if the CBCT has a greater voxel size then it may have better resolution.
67
Why is a higher resolution useful when taking xrays?
As it shows greater detail.
68
What is the gold standard imaging modality for visualising the TMJ and why?
MRI
- No radiation dose
- Shows soft tissue and bony pathology
- Good for assessing articular disc position
69
What 2 views must be taken when assessing the TMJ using MRI?
Coronal view and parasagittal view along long axis of condyle
70
What direction is normal disc displacement of the TMJ?
Anteriorly and medially
71
What 3 disc displacements of the TMJ are important to be aware of?
1. Anterior disc displacement with reduction - reciprocal clicks on opening when the disc is recaptured, expect the articular disc to lie in an anterior position in the closed mouth and will sit in a normal position on mouth opening
2. Anterior disc displacement without reduction - limitation of opening, pain
3. Anterior disc displacement and bony arthritic changes - lose joint space
72
What does SPECT stand for?
Single Photon Emission CT
73
What is the patient injected with when using nuclear medicine (SPECT) as your imaging modality when
assessing the TMJ?
IV Technetium 99-metastable (radioisotope)
74
What is the half-life of IV Technetium 99-metastable (radioisotope)?
6.5 hours
75
What is the SPECT imaging technique useful for?
When assessing condylar hyperplasia
76
What is an advantage and disadvantage of SPECT?
Highly sensitive but poorly specific - good at picking up increased metabolic activity but difficult to determine cause of the uptake
77
In SPECT what might increased metabolic activity indicate?
Pathology, increased growth, or inflammation
78
When would you use arthrography for assessing TMJ?
Rarely used
Alternative to MRI - if MRI not feasible due to contraindications (claustrophobia, implanted devices etc.)
Assessment of soft tissues - specifically articular disc
Can be used for diagnostic and therapeutic purposes
79
In arthrography what is injected into the joint space?
Iodinated contrast
80
During arthrography what is used to allow you to visualise the bony anatomy?
Fluoroscopic guidance
81
In arthrography, if contrast leaks from the lower joint space, what does this indiacate?
That there is disc perforation.
82
List the 3 major pairs of salivary glands:
1. Parotid
2. Submandibular
3. Submental
83
Where is the parotid gland located?
Located in the pre-auricular and retromandibular regions of the facial skeleton.
84
Which muscle does the parotid gland lie over anteriorly?
The masseter muscle
85
What muscle does the parotid duct pierce through?
The buccinator
86
Where does the submandibular salivary gland lie?
In the submandibular fossa deep on the lingual aspect of the body of the mandible into the submandibular space
87
Which 2 muscles does the submandibular duct pass between?
1. Mylohyoid muscle
2. Hyoglossus muscle
88
Where is the duct orifice of the submandibular gland located?
At the lingual frenum (shared with the sublingual gland duct)
89
Where does the sublingual salivary gland lie?
In the sublingual fossa anteriorly within the FOM.
90
Where is the duct orifice of the sublingual gland located?
At the lingual frenum (shared with the submandibular gland duct)
91
Where do you find minor salivary glands?
Within the mucosa overlying the hard palate, soft palate, retromolar pad, and in the FOM
92
In what case might minor salivary glands be present on imaging?
In cases where there is pathology
93
Why do we image salivary glands?
1. To visualise glandular obstruction - mucous plugs, salivary stones, neoplasia
2. To investigate dry mouth - exclude Sjogren's-related changes or changes related to a history of radiotherapy
3. To investigate swelling - secondary to Sjogren's, bacterial/viral, or possibly neoplastic growths such as malignancy
94
What 6 imaging modalities are available when imaging salivary glands?
1. Plain film radiographic techniques
2. Ultrasound
3. Sialography - involves injection of iodinated contrast into ductal anatomy
4. CT (computed tomography)
5. MRI (magnetic resonance imaging)
6. Nuclear Medicine Techniques
95
What are the 3 main plain film radiographic views that can be taken to view salivary glands?
1. Lower true occlusal
2. OPT
3. Lateral Oblique
96
What are lower true occlusal view useful for visualising in the context of salivary glands?
Submandibular salivary stones
97
What are OPTs useful for visualising in the context of salivary glands?
Sialoliths within the submandibular gland itself.
Also useful for visualising teeth to exclude the possibility of odontogenic pathology.
98
What is the issue with OPTs when visualising sialoliths within the FOM duct anterior to the genu (bend of the submandibular gland)?
Suggest a resolution to this issue:
Any sialolith within the FOM duct anterior to the genu will be superimposed over the body of the mandible making it difficult to visualise on an OPT.
Resolution: use in conjunction with a lower true occlusal view to allow better visualisation
99
Why are true laterals and PA mandibles not useful radiographic techniques for visualising salivary glands?
Due to superimposition of multiple anatomical structures.
100
What is the greatest advantage of using Ultrasound as an imaging modality when visualising salivary glands?
It does NOT use ionising radiation
101
How does an ultrasound imaging work?
It works by using high-frequency sound waves (at a frequency that cannot be heard audibly)
The ultrasound transducer creates sound waves when electric current is given to the crystals on the transducer surface.
The high-frequency sound waves enter the body and reflect back to the transducer when boundaries between different tissues are met.
Using the speed of sound and time to return the echo, the tissue depths are calculated and the ultrasound unit creates a 2D image respectively.
102
Why do ultrasounds require a coupling agent?
Sound waves have short wavelengths which are not transmittable through air - therefore must be used with a coupling agent (e.g. gel) to help sound waves get into tissues through the ultrasound transducer
103
What does an ultrasound transducer do?
It emits and detects sound waves/echoes
104
When describing an ultrasound image, what does Hypoechoic mean?
Dark
105
When describing an ultrasound image, what does Hyperechoic mean?
Bright
106
When describing an ultrasound image, what does Homogenous mean?
Uniform density
107
When describing an ultrasound image, what does Heterogenous mean?
Mixed density
108
Why is ultrasound useful for imaging salivary glands?
1. Typically glands are superficially positioned
- apart from deep lobe of the parotid
2. Can assess the parenchymal pattern (homogenous vs heterogenous), vascularity (allows assessment of any inflammation), ductal dilatation, and the presence of salivary stones or neoplastic masses (benign or malignant).
3. Can be used in conjunction with a sialogogue (ie. citric acid) to aid saliva flow/ production - will allow better visualisation of dilated ducts.
109
What does Sialography involve?
The injection of iodinated radiographic contrast into a salivary duct to look out for obstruction
110
How much iodinated contrast is injected into a salivary duct during Sialography?
Typically 0.8-1.5ml
111
Is LA required for Sialography to take place?
No
112
What are the indications for Sialography?
1. To look for obstruction or stricture (narrowing) of the salivary duct which could be leading meal time symptoms
2. To plan access for interventional procedures (basket retrieval of stones or balloon dilation of ductal strictures)
113
What are the contraindications for Sialography?
1. Existing infection
2. Mobile salivary stone - seen on plain film/us imaging
3. Allergy to contrast (very rare)
114
What imaging modality should be used as an alternative to Sialography if the patient is allergic to iodinated contrast?
MRI Sialography
115
What are the risk of Sialography?
1. Discomfort
2. Swelling - dissipates over 24-48 hours
3. Infection
4. Any stone could move
5. Allergy to contrast (very rare)
116
What 3 approaches can be used to carry out Sialography?
1. Panoramic (DPT)
2. Skull views (rotated PA mandible and lateral oblique)
3. Fluoroscopic approach
117
What are the advantages of using a fluoroscopic approach for Sialography?
1. You can watch the contrast entering the ductal system in real time
2. You can use with minimally invasive gland interventions (e.g. baskets)
3. You can see the exact location of the basket/balloon in relation to the duct
118
What are the disadvantages of using a fluoroscopic approach in Sialography?
Increased radiation dose to the patient
119
Name the 3 phases of sialography:
1. Pre-contrast phase
2. Contrast/filling phase
3. Emptying phase
120
What is the pre-contrast phase of Sialography used for?
Used to exclude other pathology which could account for symptoms (e.g. odontogenic pathology); and is also used as a base line
121
What happens in the contrast/filling phase of sialography?
Contrast is injected into salivary gland via cannula
122
At what point does the emptying phase of Sialography occur?
Roughly 5 mins after cannula is removed
123
What should you expect to see in a normal functioning salivary gland during the emptying phase of Sialography?
Contrast should have emptied from the gland and duct into the oral cavity via saliva
124
At least 2 images should be taken during Sialography.
At which point during the phases of Sialography, should these images be taken?
1. Contrast phase with cannula in place - to keep the contrast within the gland itself
2. Emptying phase with time delay - allows gland to work and produce saliva to excrete contrast into oral cavity - will give a crude assessment as to how the gland is functioning.
125
What are the properties of the iodinated contrast used in Sialography?
1. Iodine based
2. Aqueous rather than oil-based - easier to excrete from the body and less likely to cause tissue reactions if accidentally extravasated
3. Iso-osmolar
126
Name an example of the iodinated contrast used in sialography:
Omnipaque
127
How would you describe the normal appearance of a parotid gland in sialography?
Tree in winter appearance
128
How would you describe the normal appearance of a submandibular gland in sialography?
Bush in winter appearance
129
In sialography, what does a snow storm appearance within the gland indicate?
Acinar changes - caused by ductal dilatation or chronic gland inflammation
130
What technical problems can occur during sialography?
1. Contrast refluxing into oral cavity
- makes visualisation of glands more difficult
2. Air bubbles in tubing
- can mimic filling defects
3. Overfilling - blushing
- can cause pain/discomfort
- can obscure fine detail anatomical change
131
Which 2 examples of cross-sectional imaging can be used to image salivary glands?
CT
MRI
132
What are MRI scan useful for when imaging salivary glands?
Useful for pre-surgical assessment
Useful for the assessment of deep margins of lesions
133
When should you ideally carry out the MRI scan when imaging salivary glands?
Ideally carry out a couple of week prior to biopsy
134
Why should you try to carry out your MRI scan prior to your biopsy of salivary gland?
As inflammatory changes seen post biopsy can complicate diagnosis as can mimic tumour extension on MRI
135
What can cause obstructive gland disease?
Sialolith (salivary stone) or mucous plug
136
What % of Sialoliths are associated with submandibular glands?
80%
137
Which gland is more commonly associated with mucous plugs?
Parotid gland
138
What % of submandibular stones are radiopaque on plain film imaging?
80%
139
What does radiopacity of salivary stones on plain film imaging depend on?
How long the stone has been present
140
How should you image obstructive gland disease?
Initially plain film or ultrasound
- depending on the results of these you may or may not want to continue to move to sialography.
141
What other calcifications may be mistaken for sialoliths?
1. Tonsilloliths (tonsil stones)
2. Phleboliths
3. Artheromas
4. Hyoid bone
5. Elongated stylohyoid ligament
6. Calcified lymph nodes
142
What symptoms should you expect with obstructive disease?
1. Meal time symptoms
2. Prandial swelling and pain
3. Rush of saliva into the mouth when swelling dissipates
4. Bad taste
5.Thick saliva
6. Dry mouth
143
When can a salivary stone be removed using basket retrieval?
1. Stone must be mobile.
2. Stone should be located within the lumen or main duct distal to the hilum or at the anterior border of the gland (parotid).
3. Duct should be patent and wide to allow passage of the stone into the FOM.
144
When can a salivary stone be removed using balloon dilation?
Duct must be patent anterior to the stricture to allow passage of the equipment
145
What other investigations can be used in conjunction with imaging when investigating sjogrens related changes?
1. Blood tests (auto-antibodies)
2. Schirmer test
3. Sialometry
4. Labial gland biopsy
146
List some sjogrens related changes that can be seen on an ultrasound image?
1. Atrophy of gland
2. Heterogenous parenchymal pattern (leopard print)
3. Hypoechoic (darker)
4. Fatty infiltration
5. Affects pairs of glands
6. Any changes that could suggest MALT lymphoma
147
What other changes can mimic sjogrens related changes?
1. Chronic sialadenitis
2. Radiotherapy related changes
3. Any conditions leading to secondary sjogrens - SLE, sarcoidosis
148
What would we expect to see on Sialography for a patient with Sjögren's syndrome?
Acinar changes:
- Stage I - early changes - punctate sialectasia
- Stage II - globular
- Stage III - cavitation
- Stage IV - most advanced gland disease - destructive
149
Which imaging modality would you use to image a patient that has persistent swelling of their salivary gland?
Ultrasound to rule out obstruction and neoplasia
150
If neoplastic growth is found following ultrasound imaging of a salivary gland, what should be carried out?
A biopsy:
- Ultrasound-guided FNA for cytopathological diagnosis
- OR Core biopsy for tissue histopathological diagnosis
151
How would you determine from an ultrasound whether a neoplastic mass of the salivary glands is benign or malignant?
Benign:
- Well-defined
- Encapsulated
- Peripheral vascularity
- No lymphadenopathy within the neck
Malignant:
- Irregular margins
- Poorly defined
- Increased/torturous internal vascularity
- Lymphadenopathy within the neck
152
Why is it important to biopsy every neoplastic lesion that we find within the submandibular gland?
It is important as low grade malignancy will mimic benign lesions.
153
When would you image minor salivary glands?
Only when they are enlarged or pathological
154
What imaging modality would you use for imaging minor salivary glands if superficial?
Usually ultrasound if superficial
155
What imaging modality would you use for imaging minor salivary glands if deeper or if there is possible bony involvement?
MRI
156
When comparing major vs minor salivary glands, which type has a higher chance of malignancy if pathological?
MINOR salivary glands have a HIGHER chance of malignancy if pathological compared to major salivary glands.
The smaller the gland = the higher the chance of malignancy.
157
List 4 reasons as to why a pathological lesion might appear radiopaque on a radiograph?
1. Increased thickness of bone
2. Osteosclerosis of bone
3. Presence of abnormal tissues
4. Mineralisation of normal tissues
158
What is an odontoma?
A dental hamartoma - a benign tumour that is composed of dental tissues (enamel, dentine, cementum and pulp)
Similar to normal teeth - surrounded by dental follicle, matures to certain stage
159
How common are odontomas?
Very common - 1st or 2nd most common odontogenic tumour along with ameloblastomas
160
Which decade are odontomas most common in and why?
2nd decade
As this correlates with the development of normal dentition
161
What are the 2 different types of odontoma?
Compound and Complex
162
What is the difference between compound and complex odontomas?
Compound odontomas:
- Ordered dental structures
- May present as multiple mini teeth (ie. denticles)
- More common in anterior maxilla
Complex odontomas:
- Disorganised mass of dental tissue
- May have a "clump of cotton wool" appearance
- More common in the posterior body of the mandible
163
List 3 general radiographic features of odontomas:
1. Well-defined radiopacity or collection of radiopacities of varying radiodensity
2. Areas with radiodensity of enamel
3. Thin radiolucent margin (ie. follicle)
164
List some potential clinical issues associated with odontomas:
Same potential clinical issues as an unerupted tooth:
- Impaction of adjacent teeth
- External root resorption of adjacent teeth
- Development of dentigerous cyst
165
How would you manage an odontoma:
By excision
166
What is the risk of recurrence with odontomas following excision?
There is no risk of recurrence following excision.
167
What is Idiopathic Osteosclerosis (aka dense bone island or enostosis)?
Localised area of increased bone density of unknown cause.
Not pathological - no association with inflammatory, neoplastic or dysplastic processes.
Asymptomatic - incidental finding on radiograph.
168
How might idiopathic osteosclerosis affect orthodontics?
May make it more difficult to move teeth as are of bone is very dense.
169
What % of the population has idiopathic osteosclerosis?
6%
170
At what stage of human growth is idiopathic osteosclerosis most prevelant?
Adolescence - stops growing by adulthood
171
What is the most common site of idiopathic osteosclerosis?
Premolar-molar region of the mandible.
172
List some radiographic features of Idiopathic Osteosclerosis?
1. Well-defined radiopacity - often homogenous but can have slightly radiolucent internal areas; no radiolucent margin
2. Variable shape - round, elliptical, irregular, etc.
3. Size - usually <2cm
4. Not associated with teeth but will often appear next to them simply due to circumstance - teeth not displaced, no affect on PDL spaces of teeth.
173
What is sclerosing osteitis (aka condensing osteitis)?
A localised area of increased bone density in response to inflammation.
May have concurrent symptoms due to source of inflammation
No expansion or displacement of adjacent structures
174
In Sclerosing osteitis is there any expansion or displacement of adjacent structures?
No - as nothing is growing in the bone; the area of affected bone is just becoming more dense
175
List some radiographic features associated with Sclerosing Osteitis:
1. Well-defined or poorly-defined radiopacity
2. Directly associated with source of inflammation - apex of necrotic tooth, infected cyst, etc
176
How can you tell the difference between Idiopathic Osteosclerosis and Sclerosing Osteitis?
If radiographic features are inconclusive then look for a source of inflammation - e.g. check for signs/symptoms, sensibility test teeth.
If there a source of inflammation associated with the affected tooth then it is likely to be Sclerosing Osteitis.
If there is no source of inflammation associated with the tooth then it is likely to be Idiopathic Osteosclerosis.
177
What is Hypercementosis?
Excessive deposition of cementum around the root of a tooth.
Non-neoplastic and asymptomatic.
Tooth vital (unless necrotic due to another reason).
178
What causes hypercementosis?
Unknown cause however hypercementosis is more common in certain conditions - e.g. Paget's disease of bone, Acromegaly
179
Why does hypercementosis make extractions more difficult?
As hypercementosis can make the root of the tooth more bulbous
180
List some radiographic features associated with hypercementosis:
1. Single of multiple teeth involved - involves either entirety of root of just a section
2. Homogenous radiopacity continuous with root surface - radiodensity subtly different to dentine of root
3. PDL space of tooth extends around periphery
4. Margins often smooth but can be irregular
181
What is a cementoblastoma?
A benign odontogenic tumour of cementum
Occurs around the root of a tooth (which remains vital)
Often painful
Can displace adjacent teeth and cortical bone
182
How often do cementoblastomas occur and which decade do they most commonly occur in?
Cementoblastomas are rare.
They are most commonly seen in 2nd/3rd decades
183
Which area of the mouth is most commonly affected by cementoblastomas?
Mandibular premolar/1st molar region
184
List some radiographic features of cementoblastomas:
1. Attached to the tooth root - root outline may become indistinct
2. Thin radiolucent margin continuous with PDL space of root - however there is no radiolucent margin separating the tumour from the root surface
3. Well-defined and radiopaque - typically homogenous and round, however can also be mixed radiodensity and irregularly-shaped
185
What are tori?
Normal variation
Bony protuberances of normal bone at characteristic sites (middle of hard palate = torus palatinus, lingual to mandibular premolars = torus mandibularis)
Asymptomatic
May slowly increase in size
186
What causes tori?
Cause unknown - potentially related to genetic factors and masticatory stresses
187
What is the incidence of torus palatinus vs torus mandibularis?
Torus palatinus = ~20%; often arise before aged 30
Torus mandibularis = ~8%; often arise in middle age
188
List some clinical/radiographic features of Tori:
1. Solitary or multiple - torus mandibularis is often bilateral
2. Consists of cortical bone or a mix of cortical and trabecular bone
3. Sessile (smooth shallow lumps) or pedunculated
4. Variable size
189
What is an osteoma?
A benign tumour of bone
Can occur anywhere but has a predilection for craniofacial skeleton
Clinically presents as a hard, asymptomatic, slow-growing lump
Single or multiple
190
How common are osteomas and where are they most frequently found in the jaw?
Osteomas are RARE.
Can occur over a wide age range.
They are most commonly found in the posterior mandible.
191
List some radiographic features associated with Osteomas:
1. Can be entirely cortical bone or a mix of cortical and trabecular bone
2. Can be sessile or pedunculated
3. Have rounded, and smooth margins
192
Do osteomas have a malignant potential?
No, osteomas don't have a potential to become malignant.
193
What issues do osteomas pose?
Cosmetic and functional issues
194
If an osteoma is causing an aesthetic or functional issue, what would be the appropriate mode of treatment?
Excision.
195
What condition is related to the presence of multiple osteomas?
Gardner Syndrome.
196
What is Gardner Syndrome?
A rare variant of Familial Adenomatous Polyposis
197
What are the 3 main characteristics/features associated with Gardner Syndrome?
List 3 oral features that may also be seen in a patient with Gardner syndrome?
1. Colorectal polyposis
2. Osteomas (especially in mandible)
3. Soft tissue tumours (e.g. epidermoid cysts of the skin)
Also tend to have:
- Supernumaries
- Impacted teeth
- Multiple areas of idiopathic osteosclerosis
198
Why is it important to obtain a definitive diagnosis of Gardner syndrome?
As colorectal polyps inevitably become malignant.
199
What is the mean age of cancer diagnosis in a patient with Gardner Syndrome if their cancer is not removed at an earlier stage?
39 years
200
What is the cause of Gardner syndrome?
Can be inherited from parents (autosomal dominant gene) or can occur spontaneously.
201
If your undiagnosed patient presents with multiple osteomas, or multiple areas of idiopathic osteosclerosis, and impacted teeth, what should you do?
Refer them for genetic testing and investigation.
202
What is Cleidocranial Dysplasia?
A rare condition with various skeletal defects (including teeth and jaws)
203
List 6 skeletal defects, affecting the teeth and jaws, that are associated with cleidocranial dysplasia.
1. Generally delayed eruption
2. Multiple supernumerary teeth - impaction of other teeth
3. Multiple unerupted secondary teeth - multiple retained primary teeth
4. Hypoplastic maxilla with high-arched palate
5. Increased prevalence of cleft palate
6. Coarse trabecular pattern
204
List 4 skeletal defects, affecting the rest of the body, that are associated with cleidocranial dysplasia.
1. Small maxillary sinuses
2. Absent or partially formed clavicles
3. Bossing ("bulging") of the skull
4. Hypertelorism
205
What is the difference between osteomyelitis, osteoradionecrosis and MRONJ?
Osteomyelitis - Inflammation of bone and bone marrow due to bacterial infection.
Osteoradionecrosis - Bone death resulting from irradiation (high energy radiation)
MRONJ - Bone death associated with anti-resorptive or anti-angiogenic drugs.
206
List 7 radiographic features associated with osteomyelitis and osteonecrosis.
1. Osteolysis (breakdown of bone) - radiolucent areas, variable mixture
2. Osteosclerosis (thickening/densening of bone) - radiopaque areas, variable mixture
3. Irregularities on inner/outer aspects of cortical bone
4. Sequestration of bone - separated of bone due to necrosis
5. Periosteal bone reaction - periosteum layers down new areas of bone in affected area - primarily in osteomyelitis
6. Loss of lamina dura around teeth
7. Pathological fracture of bone
207
What is a central giant cell granuloma?
A reactive lesion with benign tumour-like behaviour:
- Slow growing lesion causing expansion of bone and displacement of teeth (minority of cases more aggressive and grow rapidly)
- Often asymptomatic but may be tender to palpation
- May invade into the overlying soft tissues
208
Within what age range do central giant cell granulomas occur?
Wide age range however majority occur before age 20
209
Which part of the jaw is most commonly affected by central giant cell granulomas?
Mandible anterior to molars
210
List the typical radiographic presentation of central giant cell granulomas using these headings:
- Site
- Size
- Shape
- Margins
- Internal structure
- Tooth involvement
- Effects
- Number
1. Site - mandible anterior to molars
2. Size - any size
3. Shape - unilocular
4. Margins - well-defined, poorly-corticated, scalloped
5. Internal structure - radiolucent
6. Tooth involvement - no
7. Effects - displacement of cortices and teeth, occasionally external root resorption
8. Number - single
211
What are fibro-osseous lesions?
A group of rare, benign, non-inheritable conditions where normal bone is replaced by connective tissue and abnormal bone
212
What are the 3 main types of fibro-osseous lesions?
1. Cemento-osseous dysplasia
2. Fibro-osseous dysplasia
3. Ossifying fibroma
213
Which type of fibro-osseous lesion ONLY affects the jaws?
Cemento-osseous dysplasia (COD)
214
Why is accurate diagnosis of fibro-osseous lesions important?
As the prognosis and treatment options vary significantly between different types of fibro-osseous lesions
Inappropriate management increases pt morbidity!
215
What is meant by a narrow zone of transition and a broad zone of transition?
A narrow zone of transition = obvious transition from abnormal to normal
A broad zone of transition = non-obvious transition from abnormal to normal
216
What are the 3 different forms of cemento-osseous dysplasia?
1. Focal COD - single or few localised lesions
2. Periapical COD - lesions associated w apices of anterior mandible
3. Florid COD - extensive lesion or many lesions
217
Describe the type of pt and location in which you would most commonly see a cemento-osseous dysplasia?
- 30-50 years
- Female
- Black ethnicity
- Mandible
218
What are the signs and symptoms associated with cemento-osseous dysplasia?
Clinically often NO signs or symptoms
- May be expansile (especially in florid type)
- Rarely painful
- Can become infected - pain, suppuration, etc.
219
What is the typical radiographic appearance of a cemento-osseous dysplasia?
Mixed radiodensity lesions located at the apices of vital teeth:
- Well-defined radiolucency containing various amounts of well-defined radiopaque material (appearance depends on stage of lesion maturation - fully mature lesions can appear entirely radiopaque)
- Lamina dura lost
- PDL often unaffected
- Tooth displacement or external root resorption is rare, however may occur with florid type COD
220
How can you differentiate a cemento-osseous dysplasia from a sclerosing osteitis using radiographs?
COD's are associated with VITAL teeth.
Whereas Sclerosing Osteitis is associated with NON-VITAL teeth.
221
How can you differentiate cemento-osseous dysplasia with hypercementosis and cementoblastoma using radiographs?
With COD the PDL is most commonly unaffected
Whereas with hypercementosis and cementoblastoma, the PDL is affected.
222
Which type of cemento-osseous dysplasia might you observe tooth displacement or external root resorption?
Florid COD
223
What is the management for cemento-osseous dysplasia?
1. Usually no management required:
- removal only recommended if exposed by extraction, mandibular atrophy, trauma, etc.
2. Risk of secondary infection following interventions
- biopsy is best avoided unless atypical presentation (e.g. rapid expansion)
- ideally avoid dental extractions of involved teeth - due to risk of secondary infection
3. Consider periodic radiographic review to check for the development of secondary solitary bone cysts
224
What are the 3 different forms of fibrous dysplasia?
1. Monostotic - single bone affected (most common)
2. Polyostotic - multiple lesions affecting multiple bones
3. Craniofacial - typically single lesion affecting multiple (fused) bones
225
Which type of fibrous dysplasia is the most common type?
Monostotic (single bone affected)
226
What is the incidence for fibrous dysplasia?
- 1:30,000
- most commonly presents at 25 years
- F = M
- favours posterior maxilla
227
How does fibrous dysplasia typically present clinically?
1. Facial swelling - bony expansion, may "burn out"
2. May displace teeth
3. Typically painless
228
How does fibrous dysplasia typically present radiographically?
1. Altered bone pattern:
- highly variable (granular, "orange peel", "swirling", "wispy", amorphous)
- radiodensity increases as lesion matures (becomes more radiopaque).
2. Bone enlarges but maintains rough anatomical shape
3. Margins indistinct and blend into adjacent bone:
- broad zone of transition.
229
What is the management for fibrous dysplasia?
1. No management required if not causing functional or aesthetic issues - re-contouring or radical resection only if necessary
2. Lesions normally stop growing but may reactivate, typically after a precipitating event - pregnancy, jaw surgery etc.
230
Where do ossifying fibromas most commonly occur?
In tooth-bearing areas - majority occur in the mandible
231
How does an ossifying fibroma present clinically?
1. Slow-growing bony swelling:
- however juvenile sub-type can grow rapidly!!
2. Often painless
232
At what age are ossifying fibromas most commonly seen?
~30 years
233
Are ossifying fibromas most common in males or in females?
More common in females
234
How do ossifying fibromas present radiographically?
1. Rounded expansile lesion
- affected teeth displaced and may be resorbed
2. Ranges from entirely radiolucent to completely radiopaque
- radiodensity depends on stage of lesion maturation
3. Margins usually well-defined
4. Surrounding bone may be sclerotic
235
How are ossifying fibromas managed?
- Removal indicated due to progressive growth
- Surgical enucleation or resection (usually enucleates in one piece)
- 12% recurrence rate
236
What is Paget's disease of bone?
Chronic condition causing disordered remodelling of bone:
- Affects multiple bones at the same time
- Results in enlargement of bones, malocclusion, nerve impingement (e.g. cranial nerve deficits - can affect vision, hearing etc.), brittle bones
- Majority asymptomatic
237
What are the radiographic features associated with Paget's disease of bone?
1. General enlargement of bones
2. Abnormal bone pattern (e.g. "cotton wool" appearance) - instead of normal trabecular pattern with cortical bone around it
3. Osteolytic or osteoclastic patches of bone
4. Radiodensity of altered areas linked to stage of disease (early/osteolytic, intermediate/mixed, late/osteoclastic)
5. Dental issues - migration, hypercementosis, loss of lamina dura
238
What is osteoporosis?
Decreased bone mass
239
What causes osteoporosis?
Age-related
OR
Secondary to nutritional deficiencies, medications, etc.
240
What are the radiographic features associated with osteoporosis?
1. Thinned cortices - e.g. inferior border of the mandible
2. Sparse trabecular bone pattern - general radiolucent appearance
3. Thinned lamina dura around the teeth
241
List some clinical signs and symptoms of malignancy in the oral cavity.
1. Leukoplakia - white patch
2. Erythroplakia - red patch
3. Erythroleukoplakia - red/white patch
4. Non-healing socket
5. Non-healing ulcer (- trauma)
6. Unusually mobile tooth - no hx of perio disease or heavy occlusal contacts
7. Hard firm swelling/exophytic mass
8. Lymphadenopathy within neck
9. Pain
10. Numbness
11. Problems moving tongue
12. Dysphagia - difficulty swallowing
13. Dysphonia - voice changes, particularly hoarseness
14. Loss of hearing - advanced disease
15. Pathological fracture
242
List 2 B symptoms that can indicate that there may be malignancy in the oral cavity?
1. Weight loss
2. Night sweats
243
If a patient with suspected oral cancer is experiencing night sweats what might this indicate?
Lymphoma
244
If a patient with oral cancer has developed problems with moving their tongue, which nerve may be affected?
The Hypoglossal nerve CNXII
245
If a patient with oral cancer has developed a loss of hearing, which nerves may be affected?
Facial nerve (CNVII) or Vestibulocochlear nerve (CNVIII)
246
List some radiographic signs of malignancy.
1. Moth-eaten bone
2. Non-healing sockets
3. Floating teeth - teeth with no alveolar bone support
4. Unusual periodontal bone loss - localised to a specific area
5. Spiculated periosteal reaction - "sunburst reaction"
6. Unusual uniform widening of the PDL space without any perio disease or heavy occlusal contacts
7. Generalised loss of lamina dura
8. Loss of bony outlines for anatomical features (e.g. walls of antrum, corticated margins of IDC
9. Thinning of the cortico-endosteal margin (lower border of the mandible
10. Spiking root resorption
247
If a lesion is rapidly increase, what does this likely indicate?
Indicates that the lesion is more likely to be aggressive/malignant.
**However important to note that some benign lesions can be aggressive.
248
List 3 different types of lesions that are benign and aggressive in nature?
1. Central Giant Cell Granuloma
2. Ameloblastoma
3. Odontogenic Myxomas
249
What would be the most ideal presentation in relation to definition and margins of a lesion?
An ideal presentation would be:
- Well-defined
- Corticated margins
As more likely to be a benign lesion
250
How would the margins of a lesion appear in the presence of malignacy?
They would appear moth-eaten, and uncorticated
251
If a lesion is well-defined but has a lack of cortication, what might this indicate?
It may indicate that the lesion is healing or there is superimposed infection.
252
What is cortication and how might this present on a radiograph?
Bone adjacent to the lesion has been remodelled.
In a radiograph this can be seen as a white band around the edge of the lesion.
253
Why are benign lesions often corticated?
As these lesions are often slow growing - this allows the bone to react and expand with the lesion maintaining the white corticated margin.
254
Why do benign lesions displace anatomical structures?
This is due to slow growth
255
What happens to anatomical structures in the presence of a malignant lesion?
Anatomical structures are destroyed by malignant lesions
256
What effect do benign lesions have on the IAN?
Benign lesions will displace the IAN
257
What effect do benign lesions have on teeth?
Can cause rounded root resorption
258
What effect do malignant lesions have on the IAN?
Malignant lesions will destroy the IAN
259
What effect do most benign lesions have on the IAN?
Benign lesions will displace the IAN
260
What effect do most benign lesions have on teeth?
Can cause rounded root resorption
261
What effect do most malignant lesions have on the IAN?
Malignant lesions will destroy IAN
262
What effect do most malignant lesions have on teeth?
Can cause spiking root resorption, generalised widening of the PDL and loss of lamina dura
263
List 5 types of malignant pathologies that behave slightly differently than most malignant lesions.
1. Osteosarcoma
2. Multiple Myeloma
3. Lymphoma
4. Langerhans Histiocytosis
5. Bony Metastasis
264
List 6 risk factors of osteosarcoma:
1. Fibrous dysplasia
2. Retinoblastoma
3. Previous exposure to radiation
4. Previous primary bone cancer
5. Pagets disease
6. Chronic osteomyelitis
265
What % of osteosarcomas occur in the head and neck?
~10%
266
Where is the most common site for osteomas in the H+N?
Mandible
267
What are the 3 most common symptoms associated with Osteosarcoma?
1. Persistent pain
2. Oedema
3. Paraesthesia
268
Name 2 rare symptoms that can be associated with Osteosarcoma.
1. Night sweats - b symptom
2. Weight loss - b symptom
269
How do Osteosarcomas appear on plain film radiographs at an early stage?
- Hard to diagnose
- Subtle changes to the path of cortical margins (e.g. IAC less defined and bone becomes slightly moth -eaten)
- Widening of PDL space
270
How do Osteosarcomas appear on plain film radiographs at a late stage?
Spiking periosteal reaction (sunray, sunburst)
271
What are multiple myelomas?
Multifocal proliferative disease of the plasma cells within the bone marrow which leads to the overproduction of immunoglobulins
- If there is a solitary lesion associated with this, it is known as a plasmacytoma
- However, if there are multiple lesions associated with this, it is known as a multiple myeloma.
272
List 5 features that can be associated with multiple myeloma:
1. Round/unilocular
2. Radiolucent
3. Punched out
4. Well-defined, not corticated
5. Potentially pathological fracture if the lesion is large.
273
Following DPT, If multiple myeloma is suspected what else should be carried out?
Other imagining - skeletal survey, or low dose CT full body scan
274
What is lymphoma?
A lymphoproliferative group of diseases
275
What type of lymphoma is typically found in the H&N?
B cell lymphoma
276
What 3 different ways can Langerhans Histiocystosis present?
1. Eosinophilic granulomas (solitary lesions, typically affects adolescents/young adults)
2. that Hand-Schuller Christian Disease (multifocal eosinophilic granulomas) - chronic and widespread disease, begins in childhood and may not be fully developed until early adulthood
3. Letterer-Siwe disease - widespread disease affecting children under 3 years old, most severe
276
How does lymphoma normally present?
Initially as a soft tissue lump
However, there can also be bony involvement with erosion and perforation of the cortical plates
276
How do bony metastasis most commonly present radiographically?
Typically metastasis will be uncorticated moth-eaten radiolucencies - however breast and prostate metastasis can be sclerotic/osteogenic
276
What is Langerhans Histiocystosis?
A rare condition caused by proliferation of Langerhans cells and eosinophilic leucocytes
277
Which areas of the body can body metastasis spread from?
1. Lungs
2. Prostate
3. Breast
4. Kidney
5. Thyroid
277
How can we determine radiographically whether a tumour is a primary or secondary tumour?
Radiographically we cannot determine wether this tumour is a primary tumour or a secondary tumour - therefore a pts medical history is key to guide the diagnosis.
277
What is the issue with low grade malignancy?
Can mimic benign benign pathology
277
What are the radiographic features associated with Langerhans Histiocytosis?
- Unilocular
- Radiolucent
Punched out
- Smooth outline
- Floating teeth with loss of lamina dura and pdl space
- No expansion
278
What other differential diagnosis could be responsible for the moth-eaten bone?
1. Osteomyelitis
2. Osteoradionecrosis
3. MRONJ
278
