Cysts of the Jaws Flashcards
what is a cyst
pathological cavity having fluid, semi-fluid or gaseous contents and which is not created by accumulation of pus
when do cysts have pus
when they are infected
what are the characteristics signs of a cyst
egg shell crackling sound
absence of tooth
swelling
cause loss of vitality
discolouration
increasing in size
numbness
tooth mobility
what radiographs are initially taken for a cyst
periapical
occlusal
panoramic
what radiographs are supplementally taken for a cyst
CBCT
facial radiographs (PA mandible/occipitomental)
what are the features of a cyst we look at radiographically
location
shape
margins
locularity
multiplicity
effect on surrounding anatomy
inclusion of unerupted teeth
what shapes do cysts take
spherical or egg shaped
what are the margins of cysts like
well defined
corticated
what can locularity of cysts be like
often unilocular
sometimes multilocular
how can cysts affect the surrounding anatomy
displacement
root resorption with chronic cysts
what happens if a cyst becomes secondarily infected
lose definition and cortication of margins
how can cysts be classified
structure
origin
pathogenesis
what are the 2 main categories of cysts
odontogenic
non-odontogenic
where do odontogenic cysts occur
tooth bearing areas
what is the most common cause of bony swelling sin the jaws
odontogenic cysts
what are odontogenic cysts lined with
epithelium
where do the sources of the epithelium for odontogenic cysts come from
rests of malassez
rests of serres
reduced enamel epithelium
how are the rests of malassez activated to be part of a cyst
by infection or cytokines/idiopathic
where is odontogenic epithelium located
above IAN canal
what are the most common odontogenic cysts
radicular
dentigerous
odontogenic keratocyst
what is a radicular cyst
inflammatory odontogenic cyst
how do radicular cysts start
chronic inflammation at apex of tooth due to pulp necrosis
what jaw is more common to get a radicular cyst in
maxilla
how do radicular cysts present
asymptomatic but may become infected
slow growing with limited expansion
how do you differentiate between a radicular cyst or a periapical granuloma on a radiograph
if the radiolucency diameter is larger than 15mm then most likely a cyst
what is the pathway of disease to a radicular cyst
pulpal necrosis
periapical periodontitis
periapical granuloma
radicular cyst
what are the radiographic features of a radicular cyst
well-defined radiolucency
corticated margin continuous with lamina dura of non-vital tooth
may displace adjacent structures
external root resorption sometimes
what are the histological features of a radicular cyst
epithelial lining
connective tissue capsule
inflammation in capsule
how does a granuloma turn into a radicular cyst
proliferating epithelium with central necrosis
continues growing by osmotic effect with semi-permeable wall and cytokine mediated growth
what cells are found in radicular cysts
inflammatory
mucous metaplasia
cholesterol clefts
rushton bodies
what are the causes of numbness of the lower lip
cyst
tumours
infection
trauma
what is a residual cyst
when a radicular cyst persists after loss of tooth/RCT
what is a lateral radicular cyst
radicular cyst associated with an accessory canal
located at the side of the tooth instead of apex
what types of cyst does the term inflammatory collateral cyst cover
paradental cyst
buccal bifurcation cyst
what are inflammatory collateral cysts associated with
vital teeth
what is a dentigerous cyst
developmental odontogenic cyst
what is a dentigerous cyst associated with
crown of unerupted tooth
where are dentigerous cysts more commonly found
mandible
usually third molar
what does a dentigerous cyst look like radiographically
corticated margins attached to ACJ of tooth
may displace involved tooth
tend to be symmetrical initially
variable displacement of cortical bone
what is on the histology of a dentigerous cyst
thin non-keratinised stratified squamous epithelium
how do you decide if a lesion is a dentigerous cyst or an enlarged follicle
based on follicular space
5mm+ consider cyst
cyst if radiolucency is asymmetrical
what is the usual length of follicular space from crown to follicle edge
2-3mm
what is an eruption cyst
variant of dentigerous cyst contained within soft tissue rather than bone
where and in who do you normally get an eruption cyst
incisors
children
what is an odontogenic keratocyst
developmental odontogenic cyst
where do odontogenic keratocysts usually occur
mandible
posterior
what are the radiographic features of odontogenic keratocyst
scalloped margins
25% mulitlocular
often displacement of teeth
enlarge in medullary bone space (along bone)
what pre-operative diagnostic test is needed for odontogenic keratocysts
cyst aspirate biopsy
what does an odontogenic keratocyst produce in a cyst aspirate biopsy
squames
low soluble protein content
what is the histology features of an odontogenic keratocyst
epithelial lining with keratin
palisading
daughter cysts
no rete pegs
why do odontogenic keratocysts recur
if any of the lining is left after surgery
what condition may someone have if they present with multiple odontogenic keratocysts at a young age
basal cell naevus syndrome
what are the 3 types of non-odontogenic cysts
nasopalatine duct cyst solitary bone cyst
aneurysmal bone cyst
what do nasopalatine duct cysts arise from
nasopalatine duct epithelial remnants
how do nasopalatine duct cysts present
asymptomatic
salty discharge
can displace teeth or cause swelling in palate
always involves midline
what is the histology of a nasopalatine duct cysts
non-keratinised stratified squamous and modified respiratory epithelium
what is seen on radiography of a nasopalatine duct cyst
corticated radiolucency between roots of central incisors
unilocular
how do you decide between a cyst or the incisive fossa
if >10mm definitely cyst
if <6mm is incisive fossa
if between 6-10mm monitor
what is a solitary bone cyst and who does it occur in and where
non-odontogenic cyst without epithelial lining
most common in teenagers
mandible
what is a stafne cavity
depression in bone in mandible only
where do stafne cavities present making them easy to separate from a cyst
inferior to inferior alveolar canal
what methods are used for obtaining material for histology
aspiration biopsy
incisional biopsy
excisional biopsy
if there is blood with an aspiration biopsy what type of cyst is this
aneurysmal bone cyst
what type of fluid is present in inflammatory or developmental cysts
clear straw coloured
what type of fluid indicates keratocyst
white or cream semi-solid
what is the purpose of an incisional biopsy
obtain a lining for histological analysis
what are the surgical options for cysts
enucleation
marsupialisation
what are the advantages of enucleation
whole lining can be examined pathologically
primary closure
little aftercare
what are the contraindications of enucleation
risk of mandibular fracture
dentigerous cyst
old age, ill health
clot filled cavity can become infected
incomplete removal = recurrence
damage to adjacent structures
what are the indications for marsupialisation
if enucleation would damage surrounding structures
difficult to access area
may allow eruption of tooth affected by dentigerous cyst
elderly or medically compromised
very large cysts risking jaw fracture
what are the advantages of marsupialisation
simple
can spare vital structures
what are the contraindications/disadvantages for marsupialisation
opening may close and cyst reform
complete
complete lining not available for histology
difficult to keep clean and lots of aftercare needed
long time to fill in
what is used to keep the window open after marsupialisation
obturator
