cysts of the jaws Flashcards
definition
a pathological cavity containing fluid, semi-fluid or gaseous contents and which is not created by the accumulation of pus
sterile fluid - not abscess
can get pus in cysts if infected but not initial cause
how are cysts diverse?
asymptomatic/symptomatic - often asymptomatic unless infected
slow/fast growing
indolent/destructive
are most cysts benign or malignant?
benign
describe usual cyst shape and the reason why
often spherical or egg-shaped
most grow by hydrostatic pressure - accumulation of fluid causes cyst to grow in a certain direction
usual cyst margins
well-defined and corticated
locularity of cysts
often unilocular
can be multilocular (or pseudolocular)
what might multiple cysts indicate?
a syndrome
describe effects cysts can have on surrounding anatomy
displacement of cortical plates, adjacent teeth, MS, IAC
variable degree and pattern of growth - along bone through trabecular bone - get more MD expansion in mandible than BL as dense cortical bone
RR may occur with chronic cysts
what can be included in cysts?
UE teeth
secondary infection
cysts may lose definition and cortication of margins if secondarily infected
typically associated with clinical S+S
classification
structure - epithelial lined vs no epithelial lining
origin - Odontogenic vs non-odontogenic
pathogenesis - developmental vs inflammatory
Odontogenic developmental cysts
dentigerous cyst (+eruption cyst) Odontogenic keratocyst lateral periodontal cyst
Odontogenic inflammatory cysts
radicular (+residual) cyst
inflammatory collateral cysts
- paradental cyst
- buccal bifurcation cyst
non-odontogenic developmental cyst
nasopalatine duct cyst
non-odontogenic other cysts
solitary bone cyst
aneurysmal bone cyst
no epithelial lining
where do Odontogenic cysts occur?
in tooth bearing areas
what is the most common cause of bony swelling in the jaws?
Odontogenic cysts
>90% of all cysts in the oral and MF region
2nd most common group of oral and MF lesions in adults (14-15%)
what are all Odontogenic cysts lined with?
epithelium
Odontogenic sources of epithelium
Rests of Malassez
Rests of Serres
reduced emamel epithelium
epithelial rests get switched on (often by inflammation)
Rests of Malassez
remnants of Hertwig’s epithelial root sheath
Rests of Serres
remnants of the dental lamina
reduced enamel epithelium
remnants of the enamel organ
covers crown of UE tooth then breaks down as tooth erupts
most common Odontogenic cysts
radicular (+residual) - 60%
dentigerous (+ eruption) - 18%
Odontogenic keratocyst - 12%
what type of cyst is a radicular cyst?
inflammatory Odontogenic cyst
what is a radicular cyst always associated with?
a non-vital tooth
cause of a radicular cyst
non-vital tooth
initiated by chronic inflammation at apex of tooth due to pulp necrosis
incidence of radicular cyst
most common in 4th and 5th decade
M=F
60% maxilla, 40% mandible
can involve any tooth
presentation of radicular cyst
often asymptomatic - may become infected - pain
typically slow growing with limited expansion
can produce alveolar bone expansion +/- discharge
what is the only way to confirm if a lesion has progressed to a radicular cyst?
surgically excise
stages of radicular cyst formation
pulpal necrosis
periapical periodontitis
periapical granuloma
radicular cyst
radicular cyst vs periapical granulomas
difficult to differentiate radiographically
- radicular cysts typically larger
if radiolucency diameter >15mm - 2/3 of cases will be radicular cysts
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
unilocular
uniform radiolucency
histology of radicular cysts
epithelial lining (often incomplete)
- can get ulceration/hyperplasia
- usually non-keratinised SSE 2-10 layers thick
fibrous CT vascular capsule
inflammation in capsule - inflammatory infiltrate
can get cholesterol clefts
growth of a radicular cyst
radicular cyst from granuloma
- Epithelial rests of malassez in PDL become active, divide and proliferate
radicular cysts may form by:
- proliferating epithelium with central necrosis - centre of granuloma cut off from blood supply
- OR epithelium surrounds fluid area
continued growth
- osmotic effect with semi-permeable wall
- cytokine mediated growth - also ILs - activation of osteoclasts
variable inflammation
cholesterol clefts
mucous metaplasia
hyaline/rushton bodies (only in Odontogenic epithelium)
cholesterol clefts
cholesterol in fluid due to rbcs breaking down
may get calcification within cholesterol
variants of a radicular cyst
residual cyst
lateral radicular cyst
residual cyst
when radicular cyst persists after loss of tooth (or after tooth is successfully RCT)
clinical history is important to avoid misdiagnosis
lateral radicular cyst
radicular cyst associated with an accessory canal
located at side of tooth instead of apex
cyst S+S
“egg shell” crackling on palpation - cyst thins cortical bone so when you press it cracks slightly
tingling/altered sensation - presses on nerve
- nasopalatine n (anterior palate)
- IO nerve (side nose, cheek, U lip)
movement/displacement of adjacent teeth
mobility
change in occlusion
sinus involvement - muffling sound, postural changes discomfort
diplopia - v large cyst in maxilla can push up orbital floor
painless swelling of buccal cortex
can get fluctuant swelling if bone completely resorbed
hollow percussion note
what type of cyst is an inflammatory collateral cyst?
inflammatory Odontogenic cyst
what are inflammatory collateral cysts associated with?
a vital tooth
incidence of inflammatory collateral cysts
2-7% of Odontogenic cysts
what is the pouch lined with in inflammatory collateral cysts?
non-keratinised epithelium
what is included in inflammatory collateral cysts?
paradental cyst
buccal bifurcation cyst
where does a paradental cyst typically occur?
distal aspect of PE L8
where does a buccal bifurcation cyst typically occur?
the buccal aspect of L6
roots go lingually, crowns go buccally - affects occlusion
what type of cyst is a dentigerous cyst?
developmental Odontogenic cyst
what are dentigerous cysts associated with?
crown of UE (+ usually impacted) tooth
e.g. L8s, U3s
cystic change of dental follicle
what is a dentigerous cyst the result of?
cystic change of the dental follicle
incidence of dentigerous cysts
most common in 2nd-4th decades
M>F
mandible>maxilla
features of a dentigerous cyst
corticated margins attached to CEJ of tooth (where dental follicle usually attaches)
- larger cysts may begin to envelope root of tooth
- be careful not to misinterpret
may displace involved tooth
tends to be symmetrical initially
- larger cysts may begin to expand unilaterally
variable displacement of cortical bone (i.e. bony expansion)
tooth missing from arch
round/ovoid well-defined unilocular, uniform radiolucency
histology of dentigerous cysts
thin non-keratinised SSE
- may resemble radicular cyst if inflamed
dentigerous cyst vs enlarged follicle
consider cyst if follicular space >4mm
- measure from surface of crown to edge of follicle
- assume cyst if >10mm
consider cyst if radiolucency is asymmetrical
what is an eruption cyst?
variant of dentigerous cyst
contained within ST rather than bone
Rests of Serres
presentation of an eruption cyst
associated with an erupting tooth
more commonly incisors/FPMs
almost exclusive to children
bluish over an erupting tooth
may/may not need intervention - tx conservatively and tooth often erupts
surgical excision of cyst sometimes required
ST
what type of cyst is an Odontogenic keratocyst?
development Odontogenic cyst
does an OK have a relationship to teeth?
no specific one
incidence of OK
most common in 2nd and 3rd decades
M>F
mandible>maxilla (3:1) 70-80% mandible, esp 3rd molar region
posterior>anterior
what was OK previously called?
keratocystic Odontogenic tumour
describe OK margins
often scalloped
what % of OKs are multilocular?
25%
what do OKs often cause of adjacent teeth?
displacement
root resorption uncommon
characteristic expansion of OKs
can enlarge markedly in medullary bone space before displacing cortical bone
i.e. can have significant MD expansion without BL expansion
pre-op diagnostic test - cyst aspirate for OK
contains squames
low soluble protein content: 40g/l (other cysts >50)
histology of OK
corrugated wavy epithelium parakeratosis loss of keratin if inflamed no rete pegs - can detach quite easily basal palisading - nuclei same level epithelium tends to grow in clusters
recurrence of OKs
high recurrence rate (aggressive) - need close monitoring
thin friable lining - difficulty of surgery
daughter/satellite cysts
- small cysts in lining of main cyst
- don’t leave in lining of bone as will grow - recurrence
cell nests (esp retromolar)
presentation of Basal cell naevus syndrome
multiple OKs multiple basal cell carcinomas palmar and plantar pitting calcification of intracranial dura mater skeletal abnormalities - ribs and vertebrae bifid ribs characteristic facial features - frontal and temporal parietal bossing, hypertelorism, mild mandibular prognathism abnormalities of Ca and PO4 metabolism etc
aka Gorlin-Goltz syndrome, bifid rib syndrome
cysts histologically identical to non-syndromic form but often occur at younger age e.g. 15yrs
autosomal dominant trait
non-odontogenic cysts
nasopalatine duct cyst
solitary bone cyst
aneurysmal bone cyst
what is the most common non-odontogenic cyst?
nasopalatine duct cyst
what type of cyst is a nasopalatine duct cyst?
developmental non-odontogenic cyst
what does a nasopalatine duct cyst originate from?
nasopalatine duct epithelial remnants
where does a nasopalatine duct cyst occur?
anterior maxilla
incidence of nasopalatine duct cyst
most common in 4th-6th decades
M>F
presentation of nasopalatine duct cyst
often asymptomatic
pt may note “salty” discharge
larger cysts may displace teeth or cause swelling in palate
always involve midline but not always symmetrical
histology of nasopalatine duct cyst
variable epithelial lining: non-keratinised stratified squamous and modified respiratory
radiography for a nasopalatine duct cyst
PA and/or standard maxillary occlusal
- corticated radiolucency between/over roots of central incisors
- often unilocular
- may appear “heart shaped” due to superimposition of ant nasal spine
CBCT
- indicated if better visualisation of cyst needed for surgical planning
cyst vs incisive fossa
incisive fossa
- may/may not be visible on radiographs
- midline/oval shaped radiolucency
- typically not visibly corticated
in absence of clinical issues, consider transverse diameter
- <6mm assume incisive fossa
- 6-10mm consider monitoring
- > 10mm suspect cyst
solitary bone cyst
non-odontogenic cyst without an epithelial lining
aka simple/traumatic/haemorrhagic bone cyst
incidence of a solitary bone cyst
most common in 2nd decade
M>F
mandible>maxilla
can occur in association with other bone pathology e.g. fibro-osseous lesions
clinical presentation of solitary bone cyst
usually asymptomatic - incidental finding
rarely pain or swelling
radiographic presentation of solitary bone cyst
majority in premolar/molar region of mandible
- can also occur in non-tooth bearing areas
variable definition and cortication
may have scalloped margins giving a pseudolocular appearance
may project up between the roots of adjacent teeth
Stafne cavity
not a cyst but commonly mistaken as one
actually a depression in the bone - cortical bone preserved
where does a Stafne cavity occur?
only in mandible, almost exclusively lingual
what does a Stafne cavity contain?
salivary or fatty tissue
Stafne cavity presentation
most common in 5th and 6th decades often in angle or posterior body often inferior to IAC asymptomatic well-defined, often corticated radiolucency rarely displaces adjacent structures
obtaining material for histology
aspiration biopsy - drainage of contents
incisional biopsy - partial removal
excision biopsy - complete removal
aspiration biopsy equipment
wide bore needle
5-10ml syringe
aspiration biopsy - what you can get
air
blood
pus
cyst fluid
- clear straw coloured fluid in inflammatory or developmental cysts
- white or cream semi-solid may indicate keratocyst
may be unable to withdraw plunger
purpose of incisional biopsy
to obtain a sample of the lining for histological analysis
incisional biopsy method
usually under LA
select place where lesion appears superficial
raise mucoperiosteal flap
remove bone as required - using rongeurs or a round bur
incise and remove a section of lining
procedure may be combined with marsupialisation (a tx option)
limitations of radiology
can only do provisional diagnosis
histology to confirm
tx - surgical options
enucleation
marsupialisation
what is enucleation?
all of the cystic lesion is removed - lining and contents
what is marsupialisation?
creation of a surgical window in the wall of the cyst, removing the contents of the cyst and suturing the cyst wall to the surrounding epithelium
encourages cyst to decrease in size and may be followed by enucleation at a later date
what is the tx of choice for most cysts?
enucleation
advantages of enucleation
whole lining can be examined pathologically
primary closure
little aftercare needed
disadvantages of enucleation
risk of mandibular fracture with v large cysts
dentigerous cyst? wish to preserve tooth
old age, ill health
clot filled cavity may become infected
incomplete removal of lining may lead to recurrence
damage to adjacent structures
healing following enucleation
around 36m - need long-term follow up
clot gradually replaced with bone
indications for marsupialisation
if enucleation would damage surrounding structures e.g. IDC
difficult access to area
may allow eruption of teeth affected by dentigerous cyst
elderly/medically compromised pts unable to withstand extensive surgery
v large cysts which would risk jaw fracture if enucleation was performed
can combine with enucleation as a later procedure
advantages of marsupialisation
simple to perform
may spare vital structures
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
obturator
plastic tray used to keep marsupialisation window open
non-epithelial cysts
solitary bone cyst
aneurysmal bone cyst
Stafne idiopathic bone cavity
epithelial non-odontogenic cysts
nasolabial cyst
nasopalatine cyst
globulomaxillary cyst
median cyst
epithelial Odontogenic developmental cysts
dentigerous cyst - eruption cyst OK lateral periodontal cyst - Botryoid Odontogenic cyst gingival cysts - adults - infants (alveolar cyst) glandular Odontogenic cyst calcifying Odontogenic cyst orthokeratinised Odontogenic cyst
epithelial Odontogenic inflammatory cysts
radicular cyst - residual inflammatory collateral cysts - paradental - mandibular buccal bifurcation
3 ways in which cysts grow
epithelium differentiates and grows
inflammatory process
osmotic pressure
Odontogenic cysts of inflammatory origin
radicular cyst - residual inflammatory collateral cysts - paradental - mandibular buccal bifurcation
Odontogenic cysts of developmental origin
dentigerous cyst - eruption cyst OK lateral periodontal cyst - subtype: Botyroid Odontogenic cyst gingival cysts - of adults - of infants (alveolar cyst) glandular Odontogenic cyst calcifying Odontogenic cyst orthokeratinised Odontogenic cyst
what is a Botryoid Odontogenic cyst a subtype of?
lateral periodontal cyst
non-odontogenic epithelial cysts
nasolabial cyst
nasopalatine cyst
globulomaxillary cyst
median cyst
nasolabial cyst
ST cyst
invasive
can distort nose
non-epithelial cysts
solitary bone cyst
aneurysmal bone cyst
Stafne’s idiopathic bone cavity
what is the most common broad category of cysts?
Odontogenic cysts of inflammatory origin
what does a radicular cyst form from the proliferation of?
epithelium (rests of malassez)
originate from Hertwigs root sheath (dental follicle)
usual treatment of a radicular cyst
generally simple enucleation and removal of associated tooth
- can do endo and intracanal medicament while waiting for referral appt
- as a min need RCT but warn that if they keep tooth cyst may recur
radicular cyst content
varies from watery, straw-coloured fluid through to semi-solid brownish material
where do inflammatory collateral cysts usually occur?
lateral (usually buccal) aspect of PE, vital tooth - originate from pericoronal tissue so to side of crown
what % of Odontogenic cysts are inflammatory collateral?
5%
what % of inflammatory collateral cysts are paradental?
60%
what is the usual inflammatory stimulus for paradental cysts?
pericoronitis
how does a paradental cyst relate to the tooth?
well-defined radiolucency is related to the neck of tooth and coronal 1/3 of root
what does the pathology of a paradental cyst resemble?
inflammatory radicular cyst
what % of inflammatory collateral cysts are mandibular buccal bifurcation cysts?
> 35%
mandibular buccal bifurcation cysts in children
usually buccal aspect of erupting first molar
can cause delayed eruption of 6s
what is the most common developmental Odontogenic cyst?
dentigerous cyst
what % of odontogenic cysts are dentigerous?
20%
what are dentigerous cysts lined with?
epithelium derived from reduced enamel epithelium (from enamel organ)
what is the usual tx for a dentigerous cyst?
often cyst enucleation with associated tooth or marsupialisation if large
contents of a dentigerous cyst
proteinaceous yellowish fluid
cholesterol crystals common
histopathology of an eruption cyst
synonymous to a dentigerous cyst
what % of all MF cysts are OKs?
12%
what does an OK arise from?
cell rests of Serres (originates from remnants of dental lamina)
unusual growth pattern of OKs
enlarges in AP direction
can reach large size without causing gross bony expansion
reviewing a pt after an OK
keep reviewing pt for 5 years
radiographic review annually as such high risk of recurrence due to satellite cysts
do OKs usually cause symptoms?
no
radiographic presentation of an OK
oval
well-defined, uniform radiolucency
uni or multilocular
OK contents
thick grey/white cheesy material with keratinous debris
basal cell naevus syndrome management
MDT - dentists, OMFS, neurologists, dermatologists
adequate tx of cysts
removal of tumours and regular screening
suggestion of annual OPGs
dermatological examination 3-6m, avoidance of UV light
neurological review if child
orthokeratinised odontogenic cyst
uncommon developmental cyst, used to be considered a variant of OKC
similar presentation to OKC but histologically distinct with prominent orthokeratinisation and flattened basal cell layer
unilocular without epithelial proliferations or satellite cysts
no recorded case of occurrence with naevoid basal cell carcinoma syndrome
rarely recur following simple enucleation
now a distinct entity to OKC in WHO 2017 classification
lateral periodontal cyst incidence
rare - 0.4% of odontogenic cysts
how are lateral periodontal cysts related to teeth?
associated with lateral surface of tooth root
- canine and premolar region in mandible, followed by anterior maxilla
- vital tooth, usually asymptomatic and incidental findings
what age group usually have lateral periodontal cysts?
middle aged
what do pts with lateral periodontal cysts usually present with?
may present with expansion
well-demarcated radiolucent area
histopathology of a lateral periodontal cyst
thin lining SSE
similar to gingival cysts
how are lateral periodontal cysts often treated?
simple enucleation
Botryoid odontogenic cyst
multilocular variant of LPC
often larger
more likely to recur than LPC
what are gingival cysts derived from?
remnants of the dental lamina (rests of Serres) in gingival or alveolar soft tissues
gingival cysts in adults
mandibular attached gingiva as <1cm pink/bluish sessile swellings
histology of gingival cysts in adults
thin lining of SSE
gingival cysts in infants
Bohn’s nodules
common - up to 90% of neonates
small yellow/cream nodules on edentulous alveolar mucosa
similar cysts present on palate - Epstein’s pearls, but aren’t odontogenic
naturally degenerate, no tx required
incidence of glandular odontogenic cyst
rare - 0.2% of odontogenic cysts
glandular odontogenic cyst presentation
mainly anterior mandible
slow growing, painless
unilocular/multilocular radiolucency
may reach large size with erosions of cortical plate
glandular odontogenic cyst histology
uninflamed fibrous wall lined by glandular cuboidal epithelium
problems with glandular odontogenic cyst
potentially aggressive, locally invasive nature
high recurrence rate
calcifying odontogenic cyst family
member of ghost cell family of odontogenic lesions (‘ghost’ epithelial cells in histopathology)
- originally considered variant of calcifying cystic odontogenic tumour but now regarded as developmental cyst
clinical presentation of calcifying odontogenic cyst
wide age range but usually <40years old
75% are intraosseous and either jaw may be involved
majority arise anterior to FPM
usually small about 1-3cm in diameter
shape is variable but usually monocular
adjacent teeth usually displaced +/or resorbed. bony expansion
radiographic presentation of calcifying Odontogenic cyst
initially radiolucent, unilocular or multilocular
in more advanced stage contains a variable amount of calcified radiopaque material
recurrence of calcifying odontogenic cyst
rarely recur, mainly benign course
what is the most common non-odontogenic cyst?
nasopalatine duct (incisive canal) cyst 5-10%
origin of nasopalatine duct cyst
epithelial remnants of nasopalatine duct
clinical presentation nasopalatine duct cyst
M>F, 5th-6th decades
salty discharge/taste
slowly enlarging swelling anterior palate midline
heart shaped
may be asymptomatic and found during routine Rx investigation
radiographic presentation of nasopalatine duct cyst
well-defined round, ovoid or heart shaped radiolucency
sclerotic margin
histopathology of nasopalatine duct cyst
lined by stratified squamous and respiratory/cuboidal epithelium
NV bundles found in capsule - from incisive nerves
non-epithelial jaw cysts
occur most often in long bones
occasionally found in jaws (almost exclusively in mandible)
e.g. solitary bone cyst, aneurysmal bone cyst, Stafne’s idiopathic bone cavity
solitary bone cyst
simple/haemorrhagic/traumatic bone cyst
aetiology unknown
solitary bone cyst clinical presentation
children and adults, no sex predilection
premolar/molar region of mandible
asymptomatic, chance radiographic finding
bony expansion in around 25% cases
solitary bone cyst radiographic presentation
radiolucency of variable size, irregular outline, moderately well-defined
scalloping prominent feature
surgical exploration of solitary bone cyst
rough bony-walled cavity devoid of any detectable lining
rapid healing follows
although will resolve spontaneously without
Stafne’s idiopathic bone cavity
developmental anomaly of mandible
asymptomatic, chance finding
Stafne’s idiopathic bone cavity - radiographic presentation
round or oval, well-demarcated radiolucency
between premolar region and angle of jaw
usually located below IDC (occasionally bilateral)
Stafne’s idiopathic bone cavity - surgical exploration
saucer-shaped depression of concavity lingual aspect of mandible
varying depth
majority of cases, contains ectopic salivary tissue in continuity with SMG
non-cystic radiolucent lesions for differential diagnoses
odontogenic tumours
giant cell lesions
fibrocementoosseous lesions
radiolucent non-odontogenic tumours
management of cysts
referral initial consultation special investigation? - plain film radiograph/CBCT/CT? biopsy - LA or GA? diagnosis tx plan and discussion tx options - enucleation - ideal - marsupialisation/decompression - surgical resection
what does cyst enucleation depend on?
size of cyst and type
what type of cysts is enucleation useful for?
radicular/residual cysts, dentigerous cysts, keratocysts
what is enucleation not suitable for?
ameloblastoma
complications of enucleation
mainly related to size, position and type of cyst
- damage to IAN
- communication with MS (OAC)
- pathological fracture of mandible
- risk of recurrence
marsupialisation
‘fenestration’ +/- tube/grommit insertion
what can sometimes occur after a biopsy?
marsupialisation
what is marsupialisation useful for?
useful for large simple cysts, keratocyst, dentigerous cysts
- if v concerned about jaw fracture
complications of marsupialisation
needs further surgery for cyst removal long tx before completion chance of reinfection uncomfortable need to clean cyst themselves out regularly
segmental resection
removal of cyst with margin of ‘normal’ bone
what is segmental resection mainly used for?
ameloblastoma
sarcoma
what secondary procedure does segmental resection normally require?
reconstruction of defect
Carnoy’s solution
acetic acid, chloroform, ethanol
kills epithelial cells and satellite cells
usually why wouldn’t you need a biopsy?
if associated tooth needs extraction
