Cysts Flashcards
What is a cyst?
A pathological cavity containing fluid, semi-fluid or gaseous contents
Not been created by accumulation of pus
Can be epithelial or non epithelial
What are the subdivisions of epithelial cysts
Odontogenic (inflammatory/ developmental)
Non odontogenic
What are the two main types of odontogenic inflammatory cysts?
Radicular cysts
Inflammatory collateral cysts
What are the main features of a radicular cyst?
Inflammation causing proliferation of epithelium (rests of malessez - originates from hertwigs root sheath, dental follicle)
Associated with non vital tooth
Could be apical/ lateral/ residual
What is a residual cyst?
A radicular cyst remaining in the jaw after extraction of affected tooth
What is the treatment for a radicular cyst?
Simple enucleation and removal of associated tooth
What are the histological features of a radicular cyst?
Regular lining of non keratinised squamous epithelium
Vascular capsule
Inflammatory infiltrate
What is the radiographic presentation of a radicular cyst?
Round radiolucency at root apex
Unilocular, well defined
Uniform radiolucency
What is an inflammatory collateral cyst?
Occurs on the lateral aspect of a partially erupted, vital tooth
(M3Ms the inflammatory stimulus is pericoronitis)
What type of cysts occurs on the buccal aspect of erupting fist molars in children?
Mandibular buccal bifurcation cysts
What type of cyst is a dentigerous cyst?
A developmental cyst
What are the radio graphic features of a dentigerous cyst?
Round, unilocular, well defined, uniform radiolucency
Attached to crown of unerupted tooth
What is the lining of a dentigerous cyst derived from?
Reduced enamel epithelium
What are the histopathology features of a dentigerous cyst?
Thin regular layer of non keratinised stratified squamous epithelium
What a re the main features of a dentigerous cyst?
Mostly with impacted mandibular third molars
Embraces all/ part of the crown of an unerupted tooth (attached at CEJ)
What is the treatment of a dentigerous cyst?
Cyst enucleation/ marsupialisation if large
What is an eruption cyst?
A type of developmental cyst overlying an erupting tooth
Most commonly deciduous incisors/ FPMs
What is an odontogenic keratocyst?
A type of developmental cyst which arises from the cell rests of serres (remnants of dental lamina)
Has an unusual growth pattern with high risk of recurrence
Enlarges in anterior posterior direction
Where are odontogenic keratocysts most common?
In the mandible, especially third molar region
What is the radio graphic presentation of an odontogenic keratocyst?
Oval
Well defines, uniform
Uni or multi locular
What are the histopathological features of an odontogenic keratocyst?
Thin connective tissue wall
Lined by thin, folded parakeratinised stratified squamous epithelium
What is basal cell naevus syndrome?
Autosomal dominant condition which can result in multiple odontogenic keratocysts (and increased risk of basal cell carcinoma)
What is the difference between an orthokeratinised odontogenic cyst and an odontogenic keratocyst?
Orthokeratinised odontogenic cysts rarely recur, have no occurrence with basal cell naevus syndrome and have distinct flattened basal cell layer (histologically)
What is a lateral periodontal cyst?
A rare odontogenic developmental cyst which is associated with canine/ premolar region in mandible and vital tooth
Treated with simple enucleation
What are gingival cysts?
Cysts derived from rests of serres (dental lamina)
Common in infants (bohns nodules) appearing as white/ yellow nodules on edentulous mucosa. These cysts naturally degenerate.
Can occur in adults as <1cm pink swellings on attached gingiva
What are examples of non odontogenic cysts?
Nasolabial cyst
Nasopalatine cyst
What is a nasopalatine cyst?
Most common non odontogenic cyst
Originates from epithelial remnants of nano palatine duct
Slowly enlarging swelling in anterior region of midline of palate
Appears as a heart shape radiographically
What is the lining of nasopalatine cyst?
Stratified squamous and respiratory epithelium
What are examples of non epithelial cysts of the jaw?
Solitary bone cyst
Aneurysmal bone cyst
Stafnes idiopathic bone cavity
What is a solitary bone cyst?
Aetiology is unknown
A simple/ haemorrhagic/ traumatic bone cyst
Radiographic presentation - irregular outline, moderately well defined, scalloping a prominent feature
Surgical exploration allows rapidly healing and resolving
What is stafnes idiopathic bone cavity?
Developmental anomaly of the mandible
Usually at angle of mandible
Below inferior dental canal
Saucer shape depression on lingual aspect, usually from enlarged sub mandibular gland
What is enucleation?
Removal of entire cyst lining and contents
Useful for radicular/ residual, dentigerous cysts and keratocysts
Why is enucleation not a treatment option for ameloblastomas?
Ameloblastomas have high recurrence rates due to thin, fragile lining. Therefore 1cm sound tissue must also be removed - in the mandible this is too large
What are complications of enucleation?
Damage to IAN
OAC
Pathological fracture of mandible
Risk of recurrence
What is marsupilisation?
Shrinking of the cyst by allowing drainage
Useful for large cysts, karatocyst, dentigerous cyst
What are complications of marsupilisation?
Needs further surgical treatment for removal
Long treatment before completion (1 year)
Chance of re infection
Uncomfortable
What is the size of a cyst v granuloma?
Granuloma <10mm
Cyst >10mm
Why would marsupilisation be the preferred treatment option over enucleation?
If enucleation would damage surrounding structures
If difficult access for enucleation
To allow eruption of teeth
If enucleation may risk pathological jaw fracture
What can be utilised to keep marsupilisation window open?
An obturator
What can be utilised to keep marsupilisation window clean?
Chlorhexidine mouthwash
What is an example of an odontogenic tumour?
Ameloblastoma
Ameloblastic fibroma
What are examples of giant cell lesions in the jaw?
Peripheral and central giant cell granuloma
Cherubism
What are examples of radiolucent non odontogenic tumours which may be found in the jaw?
Chondroma
Osteosarcoma
Squamous cell carcinoma
Central haemangioma
