Brainscape's Knowledge GenomeTM

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


See full index

BDS4 Radiology > Odontogenic Tumours > Flashcards

Odontogenic Tumours Flashcards

1
Q

What are the general features of Odontogenic tumours?

A

Benign: Malignant is 100 to 1

Rare

Mostly asymptomatic
-> found as incidental finding when imaging for impacted teeth or caries

Mostly arise within bones of teeth
-> can sometimes be within soft tissue

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

When may pain occur from odontogenic tumours?

A

Secondary to infection

If tumour has caused pathological bone fracture

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

What are the different classifications of Odontogenic tumours?

A

Epithelial

Mesenchymal

Mixed- only these can contain dentine AND enamel

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

What is the concept of induction in enamel formation?

A

First hard tissue formed is dentine from odontoblasts (mesenchymal origin)

Ameloblasts form enamel only when dentine has already been started
-> Presence of dentine is important in triggering maturation of ameloblasts and then starting to form enamel

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

What are the epithelial sources of odontogenic tumours? (same as cysts)

A

Rests of Malassez
-> Remnants of Hertwig’s epithelial root sheath

Rests/glands of Serres
-> Remnants of the dental lamina

Reduced enamel epithelium
-> Remnants of the enamel organ

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

How do rests of malassez form?

A

HERS forms from inner and outer odontogenic epithelium
-> HERS forms outline and hard tissues of the root- once this is completed the epithelium breaks down
-> Remnants of HERS can stay as clumps of inactive cells in PDL (vital but don’t divide)

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

How do rests of Serres form?

A

Dental lamina (responsible for formation of tooth germ) can break down and clumps of cells can persist

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

What is the reduced enamel epithelium?

A

Formed after crown has formed
-> OEE and IEE come close and stellate reticulum disappears and covers crown of unerupted tooth

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

What are examples of the different types of odontogenic tumours?

A

Epithelial
-> Ameloblastoma
-> Adenomatoid Odontogenic Tumour
-> Calcifying Epithelial Odontogenic Tumour

Mesenchymal- Odontogenic Myxoma

Mixed- Odontoma

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

What re the most common odontogenic tumours?

A

Ameloblastoma OR Odontoma account for 50% of all OT
-> debate which is most common as odontomas have classic appearance and may not be sent for histopathological assessment

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

What can make Odontogenic tumours difficult to diagnose on radiographs?

A

Appearance can be variable and change as they mature

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

What are the features of Ameloblastoma?

A

Benign

Slow growing

Locally destructive

Typically painless

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

What are the epidemiological features of Ameloblastoma?

A

1% of oral & maxillofacial tumours

Most common in 4th-6th decades

80% occur in posterior mandible

M >F

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

What are the types of Ameloblastoma?

A

Radiology:
Multicystic- more common
Unicystic- single unilocular radiolucency (lower recurrence risk)

Histology:
Follicular
Plexiform
Desmoplastic- appears more radiopaque

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

What are the radiographic features of Ameloblastoma?

A
  • Well defined
  • Corticated
  • Scalloped margins- undulating (not seen in unicystic)
  • In multi-cystic- large bony septae seen through lesion (soap bubble appearance)
  • Primarily radiolucent
  • Displacement of teeth and IAC
  • Thinning of cortices- seen in aggressive form
  • Knife edge external root resorption- clean cut resorptive lesion (not ragged)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does expansion of Ameloblastoma differ from an Odontogenic keratocyst?

A

Ameloblastoma expands in all directions equally
-> OK tends to expand along bone bucco-lingually

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

What are the histological features of Follicular Ameloblastoma?

A
  • Islands present within fibrous tissue background, bordered by cells resembling ameloblasts (columnar cells, dark stained nucleus)
  • Tissue in middle of follicles- loose tissue similar to stellate reticulum (may be cystic changes or squamous metaplasia within follicles)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the histological features of Plexiform Ameloblastoma?

A
  • Similar to follicular but different arrangement
  • Ameloblast like cells arranged in strands with stellate reticulum like tissue between
  • Fibrous tissue support
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How can ameloblastoma be differentiated from bony swelling caused by abscess?

A

Teeth in vicinity are not painful or TTP

20
Q

How are Ameloblastomas managed?

A

Surgical resection with margin
- 1cm of healthy bone taken away to help prevent recurrence
- Can be large
- Would require bone grafts and metal plates

21
Q

What is the likelihood that an Ameloblastoma will reoccur?

A

15%

22
Q

What happens when an Ameloblastoma undergoes malignant transformation?

A

It forms a Ameloblastic Carcinoma (<1% of cases)

23
Q

What is the issue with early detection of Ameloblastomas?

A

It is difficult as the lesions are small and easily missed

24
Q

What is the classic presentation of Adenomatoid Odontogenic tumour?

A

Unilocular radiolucency with internal calcifications around crown of
unerupted maxillary canine

25
Q

What are the epidemiological features of Adenomatoid OT?

A

3% of odontogenic tumours

Most common in 2nd decade

F >M

Majority occur in anterior maxilla

26
Q

How does Adenomatoid OT present?

A

Similar to dentigerous cyst but are attached further done root

Impedes eruption (cause of delayed eruption of canines)

May be asymmetrical

27
Q

What are the radiographic features of Adenomatoid OT?

A

Unilocular

Internal radiopacities and calcification
-> increase as tumour matures

Well defined margin

Corticated
-> may be sclerotic- thick white line

May displace adjacent structures
-> External root resorption is rare

28
Q

What are the histological features of AdenomatoidOT?

A
  • Epithelial cells can be arranged like ducts
  • May have rosette appearance
  • Presence of calcium- patchy appearance
  • Well-developed fibrous tissue capsule around cells (easier surgical removal and lower recurrence)
29
Q

What is the other name for a Calcifying Epithelial Odontogenic Tumour?

A

Pindborg Tumour

30
Q

What are the epidemiological features of Calc. Epith. OT?

A

1% of odontogenic tumours

Most common in 5th decade

M >F

Posterior mandible is most common site

31
Q

How do Calc Epithelium OTs grow?

A

Slowly but can become large

32
Q

What are the radiographic features of CalcEpith OT?

A
  • Can cross midline
  • Variable opacity in same lesion
  • Half are associated with unerupted tooth- you may see tooth within structure of tumour
  • Calcifications can be flecks or clumped

VARIABLE:
- Multilocular/unilocular
- Well defined/poorly defined
- Internal septa- none, fine, course

33
Q

What are the epidemiological features of Odontogenic Myxoma?

A

3-6% of odontogenic tumours

Most common in 3rd decade

F =M

Mandible > maxilla

34
Q

How do odontogenic myxomas grow?

A

Slow growth then notable bucco-lingual expansion
-> often grow between roots of teeth, if it gets bigger it may displace them

35
Q

What are the radiographic features of odontogenic myxoma?

A

Small lesions- unilocular
Large lesions- multilocular with scalloped margin

Radiolucent with septa
-> can be thick and curled giving soap bubble appearance
-> geometric pattern giving tennis racket

Root resorption is rare

36
Q

What are the histological features of Odontogenic myxoma?

A

Myxoid- loose gelatinous tissue

Stellate like cells- few in number

Presence of islands of inactive odontogenic epithelium in myxoid tissue (mesenchymal in origin)

No capsule (locally invasive) - difficult surgical removal and recurrence

37
Q

How are odontogenic myxomas managed?

A

Curretage- scraped out
-> smaller lesions

Resected- block of bone removed
-> larger lesions

38
Q

What is the recurrence rate of odontogenic myxoma?

A

25%- so follow up is required

-> lower rate in unilocular lesions

39
Q

What are odontomas?

A

Technically a Hamarotoma
-> Malformation of dental tissue- enamel, dentine, pulp, cementum

40
Q

How are odontomas similar to teeth?

A

Mature to a certain stage (i.e. do not grow indefinitely)

Can be associated with other odontogenic lesions (e.g. dentigerous cysts)
-> can give unusual appearance if these occur at same time

Surrounded by dental follicle

Lie above inferior alveolar canal

41
Q

What are the epidemiological features of Odontomas?

A

1/5 to 2/3’s of all odontogenic tumours

Most common in 2nd decade

F =M

Compound > Complex (2:1)

42
Q

What are the features of Compound Odontomas?

A

Contain ordered dental structures
-> Appear like mini teeth (denticles)

Common in anterior maxilla

43
Q

What are the features of complex odontomas?

A
  • Appears like one mass- no identifiable structures
  • Dense radiopacity
  • Posterior border of mandible
44
Q

What are the histological features of Odontomas?

A
  • Presence of dental hard tissues (comes from both epithelial and mesenchymal origin)
  • Dentine will often be seen
  • Soft tissue resembling tooth germ may be present
  • Cementum may be seen

*** Enamel is inorganic structure- slide preparation (chemical components and acids) dissolves calcified enamel, seen as spaces where enamel used to be (if not fully calcified there may be enamel present histologically)

45
Q

How are odontomas managed?

A

Surgical removal
-> orthodontic can be used to bring any impacted or affected teeth into position

BDS4 Radiology (8 decks)

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