Odontogenic tumours Flashcards
How can odontogenic tumours be discovered?
- non eruption of teeth
- incidental finding (from imaging for other reasons_
- Pain due to infection or secondary infection
- late stage bony expansion
What are the incidence of odontogenic tumours?
They are rare (1%)
Mostly are benign (100:1)
Majority are asymptomatic
Mostly arise in bone (rare cases can be within the surrounding soft tissue)
What is the classification of odontogenic tumours?
- epithelial
-mesenchymal - mixed (epithelium and mesenchyme)
What type of tumours can have dentine/enamel formation?and why?
mixed tumours due to the concept of induction
What are the odontogenic sources of epithelium?
- Rests of malassez - remnants of hertwig’s
- Rests of serres - remnants of the dental lamina
- Reduced enamel epithelium - remnants of the enamel organ
Give examples of odontogenic epithelial tumours?
Ameloblastoma
adenomatoid odotogenic tumour
Calcififying epithelial odontogenic tumour
Give examples of mesenchymal tumours
- odontogenic myxoma
Give examples of mixed tumours
Odontoma
What is ameloblastoma?
- benign epithelial tumour
- locally destructive
- slow growing
- typically painless
incidence of ameloblastoma?
1% of oral and maxillofacial tumours
- most common in 4th and 6th decades
- 8-% occur in posterior mandible
- more in males to females
What are the types of ameloblastoma?
Radiological :
multicystic
unicystic
Histological:
Follicular
plexiform
desmoplastic
How would you describe the margins of ameloblastoma?
- well-defined and corticated
- potentially scalloped
How would you describe multicystic ameloblastoma?
- may have thick/curved septa with soap bubble appearance
What are the dental effects of ameloblastoma?
- can cause displacement of adjacent structures
- can cause thinning of bony cortices
- can cause knife edge external root resorption
What is the histology of follicular ameloblastoma?
- Ameloblast like cells
- stellate reticulum like tissue
- cystic changes
- Fibrous tissue
What is the histology of plexiform ameloblastoma?
- ameloblast like cells
- stellate reticulum like tissue
- fibrous tissue
What is the management of ameloblastoma?
- surgical resection with margin
- recurrence is common
- <1% may tranform to malignancy (ameloblastic carcinoma)
What is adenomatoid odontogenic tumour?
- a benign epithelial tumour
- unilocular radiolucency with internal calcifications around crown of unerupted maxillary canine
How can adenomatoid odotogenic tumour present?
- mostly associated with unerupted tooth (commonly maxillary canine)
- Unilocular radiolucency
- mostly have internal calcification and radiopacities
- margins are well defined and coticated
- May displace adjacent structured but external root resorption is rare
What is the difference between adenomatoid odontogenic tumour and dentigerous cyst?
AOT attached to apical to cemento-enamel junction
What is the histology of AOT?
- patchy calcification
- duct like structure
What is calcifying epithelial odontogenic tumour?
- Benign epithelial tumour
- AKA pindborg tumour
- commonly affecting posterior mandible
What is the presentation of CEOT
- slow growing (can become large)
- half are associated with an unerupted tooth
- radiolucency with internal radiopacities
- can be uni ocular or multilocular
Describe the margins of CEOT ?
can be well defined or poorly defined with internal septa or without
What is odontogenic myxoma?
it is a benign mesenchymal tumour more common in mandible
What is the presentation of odontogenic myxoma?
- well defined radiolucency with thin corticated margin
- can be uniocular (small) or multiocular (large)
- tennis racket internal septa is suggestive of myxoma
What are the dental effects of odontogenic myxoma?
- buccoliingual expanssion
may cause external root resorption but this rare
What is the histology of odontogenic myxoma?
- loose myxoid tissue with stellate cells
- may contain islands of inactive odontogenic epithelium
- no capsule -> locally invasive
What is the management of odontogenic myxoma?
Curettage or resection (depending on size)
- it has a high recurrance rate (25%) - lower if unilocular
What is odontoma?
- a benign mixed tumour
- technically a hamartoma
- a malformation of dental tissue (enamel, dentine , cementum and pulp)
What are the similarities of an odontoma to teeth?
- they ature to a certain stage
- can be associated with other dental lesions such as dentigerous cysts
- surrounded by dental follicle
- lie above inferior alveolar canal
What are the types of odontoma?
- Compound
- ordered dental structures
- Appear as multiple mini teeth (denticles)
- more common in anterrior maxilla - Complex odontoma
- disorganised mass of dental tissues
- more common in posterior body of mandible
compound are more common than complex
Histologically
