Odontogentic Tumors Flashcards
Majority of odntogenic tumours are asymtomatic what are three reasons that they may be found
Non eruption of teeth
Late stage bony expansion
Incidental findings for imaging of other things
Only mixed odontogenic tumours can have dentine/enamel formation - this is due to the concept of induction what is this
Often these mixed tumours have dental hard tissues bound within these tumours due to the concept of induction . This is because
First dental hard tissue that gets formed is dentine - this comes from odontoblasts which are mesenchymal in orgin.
Ameloblasts only start forming enamel once the dentine gets laid down
Presence of dentne is important for the induction of maturation of enamel
Rests of malassez can be a source of odontogneic tumours, what are they remenants of
Hertwigs epithelial root sheath
The rests of serres can be a source of an odontogenic tumour, what are these remenants of
Remnants of the dental lamina
What is the dental lamina responsible for
The formation of the tooth germ
The reduced enamel epithelium is remenants of what
The enamel organ
What are the two most common odomtogenic tumours
Ameloblastoma and odontoma
What kind of tumor is an Ameloblastoma
Benign epithelial tumour
What are two features of an Ameloblastoma
Slow growing but locallly destructive
Typically painless
Radiologically Ameloblastoma can be multi cystic or unicystic - what one has a lower rate of recurrence
The unicystic one
What is the characteristic pattern of expansion for an Ameloblastoma
It will expand in all directions equally
Ameloblastomas cause displacement and respotion typically of adjacent structures - what is that characteristic appearance of the resorption
Knife edge appearance of external root resorption
In terms of the histology what is one of the main reasons rhat Ameloblastomas have such a high recurrence rate
Because they have no connective tissue capsule - cells can therefore grow and infiltrate the jaw bone
What is the managment of an Ameloblastoma
Surgical resection with 1cm margin of normal bone
Why do we do a 1cm margin when doing a surgical resection in Ameloblastomas
Even tho it is benign we do this due to the high reccurence rate
Unilocular radiolucney with internal calcifications around the crown of an unerupted maxillary canine is the classic presentation of what type of odontogenic tumour
Adenomatoid odontogenic tumour
What kind of tumour is an adenomatoid odontogenic tumour
A benign epithelial tumour
AOT can look similar to a Dentigerous Cyst how can we aim to tell the difference
A Dentigerous cyst is attached at the CEJ of the crown of an unerupted tooth however an AOT will be attached further down the root ( apical to the CEJ)
What tooth is an AOT most commonly assoacted with and what clincal problem does it cause
Maxillary canine
Impedes eruption
What kind of tumour is a calcifying epithelial odontogenic tumour
Begin epithelial tumour
What is the most common location for a CEOT and how may it look Radiographically
Most common in the posterior mandible
Radiolucney with internal radiopacioties - varying in size
Name a benign mesenchymal odontogenic tumour
Odontogenic myxoma
Tennis racket pattern of septa on a radiograph may indicate what kind of tumour
Odontogenic myxoma - not in all cases
How does an odontogenic myxoma tend to expand
Slow growth along bone before causing notable buccally-lingual expansion
How may an odontogenic myxoma present histologically
Loose myxoid tissue with stellate cells
No capsule so locally invasive
How is an odontogenic myxoma managed
Curettage for smaller lesion
Resection for large lesions
Why is follow up with odontogenic myxoma so important - what is the rate of recurrence
High reccurence rate of 25%
What kind of tumour is an odontoma
A begin mixed tumour
What is an odontoma
A malformation of dental tissue
Name 4 similarities of an odontoma to teeth
Mature to a certain stage ( do not grow indefinitely )
Can be associated with other odontogenic lesions ( e.g. Dentigerous cyst)
Surrounded by a dental follicle
Lies above the inferior alveolar canal
Name the two types of odontoma and which is more common
Compound
Complex
Compound is more common than complex
Describe a compound odontoma
Ordered dental structures
May appear as mutiple mini teeth ; denticles
More common in anterior maxilla
Describe a complex odontoma
Disorganised mass of dental tissues - dense radiopacity
More common in posterior body of the mandible
What are the two patterns of amelobastomas
Follicular and plexifrom
What is the typical descriptive term used to describe and Ameloblastoma on a radiograph?
Soap bubble appearnce
Why is surgery required for Ameloblastomas
Because they are relatively radio resistant
