Odontogenic Tumours Flashcards
Ameloblastoma:
- Benign or malignant?
- Painful or not?
- Expansive?
- Can it resorb teeth?
Benign
Not painful
Expansive buccally
May displace and/or resorb teeth
What are the 3 types of tumors?
1) Odontogenic epithelium without odontogenic ectomesenchyme
2) Odontogenic epithelium with odontogenic ectomesenchyme
3) Odontogenic epithelium without mesenchyme
How do we differentiate odontogenic tumours?
- Age and sex of patient
- Size and anatomical position
- Size
- Shape: unilocular/multilocular
- Outline/edge of periphery
- Relative radiodensity and internal structure
- Time present
- Decision on biopsy
What site of the mouth do ameloblastomas tend to form?
Posterior Mandible
Are ameloblastomas multilocular or unilocular?
Multilocular
What is the main differential for ameloblastoma?
Odontogenic keratocyst
Why are ameloblastomas infiltrative?
How are they treated?
- They infiltrate the surrounding bone
- The epithelium extends into the trabeculae of the medullary bone beyond the edge of the cavity
How do ameloblastomas present radiographically?
- Rounded, cyst-radiolucent ares
- Smooth, well-defined, corticated margins
- Radiolucent with radio-opaque septa
What is the treatment of ameloblastomas?
- Excision with 1cm bone margins
Why can ameloblastomas be hard to diagnose?
Sometimes present as a unicystic lesion.
Occurs in young people.
These can be enculated without reoccurance.
Is a calcifying epithelial odontogenic cyst formed from epithelium or mesenchymal cells or both?
Epithelium
What does a calcifying epithelial odontogenic tumour contain?
Amyloid proteins secreted by the odontogenic epithelium
What tissue is ameloblastic fibroma formed from?
- Epithelium and ectomesenchyme
What feature can be seen on histology of an adenomatoid odontogenic tumour?
- Duct like spaces
What cells can be seen on histology of a calcifying odontogenic cyst?
- Flattened epithelial cells: nuclei remains at centre of the cell where the nuclei used to be
- Nuclei die and form a hole
What are the two types of odontomes?
COMPLEX = completely dirogaised enamel and dentine, minimal soft tissues present
COMPOUND = made up of tooth like structures that cluster to form compound tissue.
What is an odontogenic fibroma formed from?
Fibrous odontogenic epithelium.
Spindle spaced fibroblasts and bundle of collagen fibres
What is an odontogenic myxoma formed from?
Where does it usually form in the jaw?
What is the treatment for this tumour?
- Composed of myxoid connective tissue
- Little collagen and lots of proteoglycan ground substance
- Posterior mandible
- Local resection due to bone permeation
What is the main differential of a cementoblastoma?
PAINFUL bony swelling
How is a cementoblastoma seen on X ray?
- Radio-opaque circular tumour with a radiolucent outline
What are some signs that may lead us to think a tumour is malignant?
- Swelling
- Pain
- Numb lip or palate
- Radiolucency
- Root resorption and bone resorption
- Tooth mobility
- Pathological jaw fracture
- Enlarged lymph nodes
- History of malignancy
