BDS4 Cysts of the Jaws Flashcards
what is a cyst?
-cavity fluid, semi-fluid or gaseous contents
- not created by the accumulation of pus
signs and symptoms of cysts?
Often asymptomatic unless infected
what is radiograph investigation of cyst?
- Initial
*Periapical radiograph
*Occlusal radiograph
*Panoramic radiograph - Supplemental
*Cone beam CT (CBCT)
*Facial radiographs
**PA mandible view
**Occipitomental view
what are radiographic features of cysts?
- Location
- Shape
*Often spherical or egg-shaped
*Most grow by hydrostatic pressure - Margins
*Often well defined
*Often corticated - Locularity
*Often unilocular
*Can be multilocular (or pseudolocular) - Multiplicity
*Single, bilateral, multiple
*Multiple cysts may indicate a syndrome - Effect on surrounding anatomy
*Displacement of cortical plates, adjacent
teeth, maxillary sinus, inferior alveolar canal
*Variable degree & pattern of growth
*Root resorption may occur with chronic
cysts - Inclusion of unerupted teeth
what happens to secondary infection cysts?
- Cysts may lose definition & cortication of
margins if secondarily infected - Typically associated with clinical
signs/symptoms
what are 2 classes of cysts?
- odontogenic
- non-odontogenic
what are types of odontogenic and non-odontogenic cysts
odontogenic
- developmental
*Dentigerous cyst (& eruption cyst)
*Odontogenic keratocyst
*Lateral periodontal cyst
- inflammatory
*Radicular cyst (& residual cyst)
*Inflammatory collateral cysts
**Paradental cyst
**Buccal bifurcation cyst
non-odontogenic
- developmental
*Nasopalatine duct cyst
- other
*Solitary bone cyst
*Aneurysmal bone cyst
both no epithelial lining
what are odontogenic cysts?
- occur in tooth bearing areas
- most common cause of bony swelling in jaws
- all lined with epithelium
what are the sources of odontogenic epithelium
- 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
what are most common odontogenic cysts?
- Radicular cyst (& residual cyst)
* 60% of odontogenic cysts - Dentigerous cyst (& eruption cyst)
- Odontogenic keratocyst
what is radicular cyst? and incidence
- Inflammatory odontogenic cyst
*Always associated with a non-vital tooth
*Initiated by chronic inflammation at apex of tooth due to
pulp necrosis - incidence
*most common in 4th and 5th decades
what is presentation of radicular cyst?
presentation
- often asymptomatic
*may become infected ->pain
- typically slow growing with limited expansion
what is difference between radicular cyst and periapical granulomas
- difficult to differentiate radiographically
- radicular cyst typically larger
- if radiolucency diameter>15mm -> 2/3’s of cases will be radicular cysts
what is path to radicular cyst?
pulpal necrosis -> periapical periodontitis -> periapical granuloma -> radicular cyst
what are radiographic features of 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 &/or contain dystrophic calcification
what is histology of radicular cyst?
- Epithelial lining (often incomplete)
- Connective tissue capsule
- Inflammation in capsule
- variable inflammation
- cholesterol clefts
- mucos metaplasia
- hyaline/rushton bodies
what is radicular cyst from granuloma?
- Epithelial rests of Malassez proliferates in periapical granuloma
- Radicular cysts may form by:
*Proliferating epithelium with central necrosis
*OR epithelium surrounds fluid area - Continued growth
*Osmotic effect with semi-permeable wall
*Cytokine mediated growth
what are variants of radicular cyst?
- Residual cyst
-radicular cyst persists after loss of tooth or RCT - Lateral radicular cyst
-Radicular cyst associated with an accessory canal
-Located at side of tooth instead of apex
what are inflammatory collateral cysts?
- associated with vital tooth
what is inflammatory collateral cyst collective term for?
- Paradental cyst
*Typically occurs at distal aspect of partially-erupted mandibular third molar - Buccal bifurcation cyst
*Typically occurs at buccal aspect of mandibular first molar
what is this?
dentigerous cyst
what is dentegous cyst
- Developmental odontogenic cyst
*Associated with crown of unerupted (& usually impacted) tooth
*Cystic change of dental follicle
what is incidence of dentigerous cyst?
- common 20-40
- male and mandible more
explain features of dentigerous cyst?
- Corticated margins attached to cemento-enamel
junction of tooth
*Larger cysts may begin to envelope root of tooth - May displace involved tooth
- Tend to be symmetrical initially
*Larger cysts may begin to expand unilaterally - Variable displacement of cortical bone (i.e.
bony expansion)
what is histology of dentigerous cyst?
- Thin non-keratinised stratified squamous epithelium
*May resemble radicular cyst if inflamed
what is difference between dentigerous cyst and enlarged follicle?
- Consider cyst if follicular space 5mm or more
*Measure from surface of crown to edge of follicle
*Normal follicular space typically 2-3mm
*Assume cyst if >10mm - Consider cyst if radiolucency is asymmetrical
what is this?
eruption cyst
what is eruption cyst?
- Variant of dentigerous cyst
*Contained within soft tissue rather than bone - Associated with an erupting tooth
*More commonly incisors
*Almost exclusive to children
what is this?
Odontogenic keratocyst (OKC)
what is odotongeic keratocyst? incidence?
- Developmental odontogenic cyst
*No specific relationship to teeth
incidence - 20 and 30s
- male and mandible and posterior more
what are features of odonotgenic kertocyst?
- Often have scalloped margins
- 25% are multilocular
- Often cause displacement of adjacent
teeth
*Root resorption uncommon - Characteristic expansion
*Can enlarge markedly in medullary bone
space before displacing cortical bone
what are pre-op diagnostic tests of okc?
- Cyst aspirate
*Contains squames
*Low soluble protein content
what is okc histology?
- parakeratosis
- basal palisading
- loss of keratin if inflammed
what is recurrence of okc?
thin firable lining -> difficulty of surgery
- daughter cysts
- cell nests
what is basal cell naevus syndrome?
- Presentation
*Multiple odontogenic keratocysts
*Multiple basal cell carcinomas
*Palmar & plantar pitting
*Calcification of intracranial dura mater - Cysts histologically identical to non-syndromic form but often occur at a younger age (e.g. 15 years)
what are example of non-odontogenic cysts?
Nasopalatine duct cyst
*Most common
* Solitary bone cyst
* Aneurysmal bone cyst
what is nasoplaatine duct cyst? incidence
- Developmental non-odontogenic cyst
*Arises from nasopalatine duct epithelial remnants
*Occurs in anterior maxilla
incidence - most common 40-60
- males
what this
naso palatine duct cyst
what is presentation of naso palatine duct cyst?
- Often asymptomatic
- Patient may note “salty” discharge
- Larger cysts may displace teeth or cause swelling
in palate - Always involve midline but not always symmetrical
what is histology features of nasopalatine duct cyst?
- Variable epithelial lining
*Non-keratinised stratified squamous
& modified respiratory
what is radiography of nasopalatine duct cyst?
- Periapical &/or standard maxillary occlusal
*Corticated radiolucency between/over roots of central incisors
*Often unilocular
*May appear “heart shaped” due to superimposition of anterior nasal spine - Cone beam CT
*Indicated if better visualisation of cyst needed for surgical planning
what is difference between cyst and incisive fossa
- Incisive fossa
*May or may not be visible on radiographs
*Midline, oval-shaped radiolucency
*Typically not visibly corticated - In the absence of clinical issues, consider the
transverse diameter
*<6mm: assume incisive fossa
*6-10mm: consider monitoring
*>10mm: suspect cyst
what is this line
tranverse diamete
what is solitary bone cyst? incidence
- Non-odontogenic cyst without an epithelial lining
incidence - 20s
- male, mandible more and occur in assocaition with other bone pathology
what is presentation of solitary bone cyst?
Clinical
* Usually asymptomatic → incidental finding
* Rarely pain or swelling
what is solitary bone cyst radiolographically?
- Majority in premolar/molar region of mandible
*Can also occur in non-tooth-bearing areas - Variable definition & cortication
- May have scalloped margins giving a pseudolocular appearance
- May project up between the roots of adjacent teeth
what is this?
solitary bone cyst
what is stafne cavity?
- Not a cyst but commonly mistaken as one
*Actually a depression in the bone
*Only occur in mandible, almost exclusively lingual
*Contains salivary or fatty tissue
what is presentation stafne cavity?
- Most common in 5th & 6th decades
- Often in angle or posterior body
- Often inferior to inferior alveolar canal
- Asymptomatic
- Well-defined, often corticated radiolucency
- Rarely displaces adjacent structures
what is this
stafne cavity
how to obtain material for cyst investigation?
- Aspiration biopsy – drainage of contents
- Incisional biopsy – partial removal
- Excisional biopsy – complete remova
for aspiration biopsy what do you need and can get?
- 5-10ml syringe
- Can get:
*Air
*Blood
*Pus
*Cyst fluid
*Clear straw coloured fluid in inflammatory or developmental cysts
*White or cream semi-solid may indicate keratocyst
what is purpose and methodology for incisonal biopsy?
purpose
* To obtain a sample of the lining for histological analysis
methodology (usually under LA)
* Select place where lesion appears superficial
* Raise mucoperiosteal flap
* Remove bone as required – using rongeurs or a round bur
* Incise & remove a section of lining
Procedure may be combined with marsupialisation (a treatment option)
what is treatment options of cysts?
- Enucleation
- Marsupialisation
what is enucleation?
- All of the cystic lesion is removed
- Treatment of choice for most cysts
what is advantages and disadvantages/contraindications of enucleation?
adv
* Whole lining can be examined pathologically
* Primary closure
* Little aftercare needed
diadv/contraindic
* Risk of mandibular fracture with very large cysts
* For dentigerous cyst, may 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
what is marsuplisation?
- Creation of a surgical window in the wall of the cyst, removing the contents of the cyst & suturing the cyst wall to the surrounding epithelium
- Encourages the cyst to decrease in size & may be followed by enucleation at a later date
whats is indications of Marsupialisation
- If enucleation would damage surrounding structures (e.g. ID nerve)
- Difficult access to the area
- May allow eruption of teeth affected by a dentigerous cyst
- Elderly or medically compromised patients unable to withstand extensive surgery
- Very large cysts which would risk jaw fracture if enucleation was performed
- Can combine with enucleation as a later procedure
what is advantages and disadvanatges/cintraindications of Marsupialisation?
- Advantages
*Simple to perform
*May spare vital structures - Contraindications/disadvantages
*Opening may close & cyst may reform
*Complete lining not available for histology
*Difficult to keep clean & lots of aftercare needed
*Long time to fill in
what is obturator for?
- Used to keep marsupialisation window open
1) What does a dentigerous cyst develop from?
2) How does it appear histologically?
3) How does it appear radiographically?
4) Where is it most commonly seen?
1) Dentalfollicleatreducedenamel epithelium and crown.
2) Thin, non-k epithelium, capsule with NO inflammation.
3) Attached at ACJ, may encompass whole tooth, unilocular.
4) Unerupted 8s and 3s
1) Where does a KCOT develop from
2) How does it appear histologically
3) How does it appear radiographically?
4) Why is it problematic?
5) What condition is it associated with
1) RestsofSerresfromdentallamina.
2) Thin epithelium, parakeratosis, pallasading basal layer, thin capsule, daughter cysts/satellite cysts.
3) Multilocular, scalloped.
4) Recurs due to thin capsule and daughter cysts, late
presentation as grows mesio-distally.
5) Gorlin-Goltz Sydrome.
Cysts
1) - What is a cyst?
2) - Give 2 inflammatory cysts
3) - Give 2 developmental cysts
4) - Give 2 non-odontologenic cysts
5) Give 2 common treatment options with advantages and disadvantages for both?
1) A pathological cavity with fluid, semi-fluid or gaseous contents, not created by pus accumulation
2) o Radicular cysts
o Residual cyst (cysts left after extraction)
o Paradental cyst
3) o Dentigerous cyst
o Odontogenic keratocyst odontogenic tumour (KCOT)
o Eruption cyst
4) o Simple bone cyst
o Nasopalatine cyst
o Nasolabial cyst
5) o Enucleation:
▪ All of the cystic lesion is removed
▪ Advantages – whole lining examined; little after care; allows
primary closure
▪ Disadvantages – risk of mandible fracture, incomplete removal can lead to recurrence, damage to adjacent structure risk, clot filled cavity may become infected, tooth loss can occur.
o Marsupialisation
▪ Creation of a surgical window in the wall of the cyst removing
the contents and suturing the cyst wall to surrounding epithelium
▪ It encourage the cyst to decrease in size and may be followed by
enucleation at a later date.
▪ Advantages – simple to perform and may spare vital structures
▪ Disadvantages – cyst may reform, complete lining not available
for histology sampling, difficult to keep clean and lots of
aftercare required
6) - How does a radicular cyst develop?
7) - How does it appear histologically and radiographically?
6) o These are dental or periapical cysts associated with the roots of the teeth and generally non-vital teeth
o It usually has an inflammatory aetiology and is sequel to pulpitis and periapical granuloma
o Develops from epithelial rests of Malassez from Hertwig’s root sheath.
7) o Radiographically:
▪ Well defined radiolucency around the apex of a tooth/teeth
▪ Unilocular
▪ Corticated margins of the lesion continuous with lamina dura on
either side of the root o Histologically:
▪ epithelial lining often incomplete; CT capsule with related inflammation in capsules; may form by proliferating epithelium with central necrosis or epithelium surrounded fluid area.
▪ Rests of malassez,
▪ Cholesterol clefts usually associated with epithelial
discontinuities and project into the cyst lumen found in the cyst
fluid
▪ variable inflammation; mucous metaplasia
▪ Hyaline/Rushton bodies represent some type f epithelial product
as they are eosinophilia bodies.
