Cysts of the Jaw Flashcards
Define a cyst.
A pathological cavity having fluid, semi-fluid or gaseous contents and which is not created by the accumulation of pus.
What is the most common cause of bony swellings in the jaws?
odontogenic cysts
What are odontogenic cysts lined with?
Epithelium.
* rests of Malassez
* rests of Serres
* reduced enamel epithelium
What are the 3 most common odontogenic cysts?
- radicular cyst (and residual cyst) 60%
- dentigerous cyst (and eruption cyst) 18%
- odontogenic keratocyst 12%
What is a radicular cyst?
- inflammatory odontogenic cyst
- assciated with a non-vital tooth
- initiated by chronic inflammation at tooth apex due to pulp necrosis
- often asymptomatic unless infected
In which jaw are radicular cysts more common?
maxilla
What are the radiographic features of a radicular cyst?
- well-defined, round/oval radiolucency
- corticated margin continuous with lamina dura of non-vital tooth
- larger lesions may displace adjacent structures
- long-standing lesions may cause external root resorption and/or contain dystrophic calcification
What are histological features of a radicular cyst?
- incomplete epithelium
- connective tissue capsule
- inflammation in capsule
What is a residual cyst?
when radicular cyst persists after loss of tooth (or after tooth is successfully RCTed)
What is lateral radicular cyst?
- radicular cyst associated with an accessory canal
- located at side of tooth instead of apex
What are inflammatory collateral cysts?
- odontogenic
- associated with vital tooth
- collective term for paradental cyst and buccal bifurcation cyst
What is a paradental cyst?
- odontogenic
- associated with vital tooth
- typically occurs at distal aspect of partially erupted mandibular third molar
What is a buccal bifurcation cyst?
- odontogenic
- associated with vital tooth
- typically occurs at buccal aspect of mandibular first molar
What is a dentigerous cyst?
- also known as follicular cyst
- developmental odontogenic cyst
- associated with the crown of an unerupted (and usually impacted) tooth
What are radiographic features of a dentigerous follicular cyst?
- corticated margins attached to CEJ of the tooth
- may displace the involved tooth
What are histological features of a dentigerous follicular cyst?
- thin non-keratinised stratified squamous epithelium
- may resemble radicular cyst if inflamed
What is the difference between a dentigerous follicular cyst and an enlarged follicle?
consider cyst if follicular space > 4mm
* measure from crown surface to edge of follicle
* assume cyst if > 10mm
What is an eruption cyst?
- variable of dentigerous follicular cyst
- contained within soft tissue rather than bone
- associated with an erupting tooth
What is an odontogenic keratocyst?
- developmental odontogenic cyst
- no specific relationship to teeth
- M > F
- mandible > maxilla
- posterior > anterior
What are radiographic features of odontogenic keratocyst?
- scalloped margins
- 25% are multilocular
- often cause displacement of adjacent teeth
- characteristic expansion: significant mesio-distal expansion without bucco-lingual expansion (significant enlargement in medullary bone space before displacing cortical bone)
What is the presentation of Basal Cell Naevus Syndrome?
- multiple odontogenic keratocysts
- multiple basal cell carcinomas
- palmar and planter pitting
- calcification of intracranial dura mater
Also known as:
* Gorlin-Goltz syndrome
* bifid rib syndrome
What is the most common non-odontogenic cyst?
nasopalatine duct cyst
What is a nasopalatine duct cyst?
- developmental non-odontogenic cyst
- arises from nasopalatine duct epithelial remnants
- occurs in anterior maxilla
- also known as incisive canal cyst
What is the presentation of nasopalatine duct cyst?
- asymptomatic
- “salty” discharge
- larger cysts may displace teeth or cause swelling in palate
What are the histological features of nasopalatine duct cyst?
non keratinised stratified squamous and modified respiratory epithelium
What are the radiographic features of nasopalatine duct cyst?
- corticated radiolucency between/over roots of central incisors
- often unilocular
- may appear “heart-shaped” due to superimposition of anterior nasal spine
What is a solitary bone cyst?
- non-odontogenic cyst without an epithelial lining
- also known as simple/traumatic/haemorrhagic bone cyst
- asymptomatic
- incidental finding
What are radiographic features of solitary bone cysts?
- majority in premolar/molar region of mandible
- can also occur in non-tooth bearing areas
- may have scalloped margins (pseudolocular appearance)
- may project up between roots of adjacent teeth
What is a Stafne cavity?
- not a cyst
- depressionn in the bone
- only in mandible
- lingual (inferior to inferior alveolar canal)
- contains salivary or fatty tissue
- asymptomatic
- well-defined, often corticated radiolucency
What further investigations can be done for cysts?
Radiology
Histological analysis (required to confirm diagnosis):
* aspiration biopsy (drainage of contents)
* incisional biopsy (partial removal)
* excisional biopsy (complete removal)
What are the treatment options for cysts?
Enucleation
All of the cystic lesion is removed.
Marsupialisation
* create a surgical window in the wall of the cyst
* remove the contents
* suture cyst wall to the surrounnding epithelium
* this encourages the cyst to decrease in size
* may be followed by enucleation later
What is the treatment of choice for most cysts?
Enucleation
What are the advantages of enucleation?
- whole lining cann be examined pathologically
- primary closure
- little aftercare needed
What are contraindications/disadvantages of enucleation?
- risk of mandibular fracture with very large cysts
- old age; ill-health
- clot-filled cavity may become infected
- wish to preserve tooth (dentigerous follicular cyst)
- incomplete removal of lining may lead to recurrence
- damage to adjacent structures
What are indications of marsupialisation?
- if enucleation would damage surrounding structures e.g. ID canal
- difficult access to the area
- may allow eruption of teeth affected by a dentigerous follicular cyst
- elderly or medically compromised patients unable to withstand extensive surgery
- very large cysts which would risk aw fracture if enucleation was performed
- can combine with enucleation as a later procedure
What are advantages of marsupialisation?
- simple to perform
- may spare vital structures
What are contraindications/disadvantages of marsupialisation?
- opening may close and cyst may reform
- complete lining not available for histology
- difficult to keep clean and lots of aftercare needed
- long time to fill in
