Odontogenic Tumours Flashcards
What is the incidence of odontogenic tumours?
- Rare 1% oral and maxillofacial lesions
- Benign»_space; malignant 100:1
- Majority asymp
- Mostly arise in bone of jaws
When are you usually going to identify a odontogenic tumour (as they are mostly asmyp)
- Non eruption of teeth
- Late stage bony expansion
- Incidental on imaging for other things
What are the 3 groups based on tissue of origin that tumours odontogenic tumours can be classified into?
- Epithelial
- Mesenchymal
- Mixed (epithelium and mesenchyme)
Give the odontogenic sources of epithelium
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
Give an example of epithelial, Mesenchymal and Mixed odontogenic tumour
Epithelial - Ameloblastoma
Mesenchymal - odontogenic myxoma
Mixed - Odontoma
What is an Ameloblastoma? Give the the incidence
- Benign epithelial tumour
- locally destructive but slow growing
- Typ painless
Incidence
- 1 % oral and maxillofacial
- 40-60yrs
- 80% post mandible
- M > F
Give the Radiological and histological Ameloblastoma types
Radiological
- Multicystic (85-90%)
- Unicystic (younger pts, lower recurrence)
Histological
- Follicular
-Plexiform
- Desmoplastic
Give the radiological features of ameloblastoma
- Well definied corticated margins , potentially scalloped
- Multicystic has thick curved septa (soap bubble appearance)
- Radiolucent (rare variants can be radiopaque)
Adjacent structures - Displacement
- Thinning of bony cortices
- Knife edge external root resorption
Give the histological features of Follicular ameloblastoma
- Ameloblast-like cells
- Stellate reticulum like tissue
- Cystic changes
- Fibrous tissue
Give the Histological features of Plexiform ameloblastoma
What is the management of Ameloblastoma?
- Biopsy for histopathological analysis
- Surgical resection with margin
Inform pt that Recurrence relatively common 15% and <1% risk of malignant transformation (deemed Ameloblastic carcinoma
What is an Adenomatoid odontogenic tumour (AOT)? Give the incidence
- Benign epithelia tumour
- Unilocular radiolucency with internal calcifications around crown of unerupted max canine - typ presentation
Incidence
- 3% odotnogenic tumours
- 20yrs
- F > M
- Ant maxilla
What are the radiographic features of AOT?
- 75% ass with unerupted tooth (most common max canine)
- Sim to dentigerous cysts byt attached apical to cemento-enamel junction and impedes eruption
- Unilocular radiolucency
- Internal calcifications
- Well defined and corticated/ sclerotic margins
- May displace adjacent structure but external root resorption rare
Give the histological features of AOT
- Dustinctive with patchy calcification
- Duct like structure
What is a Calcifying epithelial odontogenic tumour (CEOT)? Give the incidence
- Benign epithelial tumour
Incidence
- 1% odontogenic tumours
- 50yrs
- M > F
- Post mand
What is the radiographic features of CEOT?
- Slow growing but can become large
- Ass with unerupted tooth (usually)
- radiolucency with internal radiopacities (calcifications)
- Unilocular or Multilocular
- Well defined or poorly defined
- May have no fine or coarse internal septa
What are the radiographic features of Odontogenic myxoma?
- Well defined radiolucency +/- thin corticated margins
- Larger lesions multilocular with scalloped margins (soap bubble)
- Slow growth along bone before causing notable buccal-lingual expansion
- Scallops between teeth but larger lesions may cause displacement
- External root resorption rare
Give the histological features of Odontogenic myxoma
- Loose myxoid tissue with stellate cells
- may contain islands of inactive odontogenic epithelium
- No capsule therefore locally invasive
What is an Odontoma? Why does it form? What similarities to teeth are there?
- Benign mixed ‘tumour’
- technically a hamartoma
Forms
- Malformation of enamel, dentine, cementum and pulp
Sim to teeth
- Mature to a certain stage (don’t grow indefinitely)
- Can be ass with other odontogenic lesions (dentigerous cysts)
- Surrounded by dental follicle
- Lie above IANC
Incidence
- 1/5 to 2/3rds all odontogenic tumours
- Most common 20s
- F = M
What are the two types of Odontoma? Describe them
Compound odontoma
- Ordered dental structures (may appear as multiple mini teeth)
- Ant max
Complex Odontoma
- Disorganised mass of dental tissues
- Post body of mand
Compound : Complex 2:1
