1 Odontogenic Cysts Flashcards
encountered commonly in dental practice
odontogenic cysts
cause of odontogenic cysts
stimulation and proliferation of odontogenic epithelium, either inflammatory or developmental
an epithelium-lined cavity, often fluid-filled
odontogenic cyst
What happens when pressure builds up inside of the cyst?
resorption of surrounding bone or growth of the cyst
inflammatory (2) vs developmental (7) odontogenic cysts
Inflammatory: periapical (radicular) cyst, residual cyst
Developmental: dentigerous cyst, OKC, orthokeratinized odontogenic cyst, lateral periodontal cyst, gingival (alveolar) cyst of the newborn, calcifying odontogenic cyst, glandular odontogenic cyst
most common developmental odontogenic cyst, 2nd most common cyst of the jaws
dentigerous cyst
most common cyst of the jaws
periapical cyst
NAME THAT CYST: ONLY occurs with unerupted (impacted) teeth
dentigerous cyst
NAME THAT CYST: classic presentation = cyst lining attaches to tooth at the CEJ and encircles the crown
dentigerous cyst
NAME THAT CYST: accumulation of fluid causes separation of the follicle (REE) from the crown, some extend further down the tooth root or more laterally
dentigerous cyst
most common location of dentigerous cysts
mandibular 3rd molars (65%), then maxillary canines, maxillary 3rd molars, mandibular 2nd PMs
NAME THAT CYST: wide age range, but most often diagnosed between 10-30 yo
dentigerous cyst
NAME THAT CYST: depending on size, may be asymptomatic (incidental radiographic finding) or cause painless expansion of the bone in the area, can become very large in size
dentigerous cyst
NAME THAT CYST: unilocular radiolucency associated with the crown of an unerupted tooth, well-defined, corticated
dentigerous cyst
Potential things that dentigerous cysts can cause:
- displacement of the impacted tooth
- root resorption of adjacent teeth
tx for dentigerous cyst
- enucleate cyst along with tooth
- marsupialization/decompression for large lesions
- recurrence is rare
NAME THAT CYST: small risk for malignant transformation of the cyst lining if not treated
dentigerous cyst
NAME THAT CYST (histo): non-keratinized stratified squamous epithelium lining, fibrous CT wall, may see secondary inflammation
dentigerous cyst
Marsupialization vs decompression
- Function?
- Poor surgery candidates?
- Difference between them
- Negtive?
When the cyst is exposed to the oral cavity, there is a reduction in osmotic pressure –> slow decrease in size so it can be removed later when a less extensive surgery (preserve bone, teeth, and vital structures.
Large lesions and kids are poor surgery candidates.
Marsupialization- cyst lining directly sutured to oral mucosa
Decompression- drainage tube place
Both require extensive patient/family compliance.
NAME THAT CYST: soft tissue counterpart of a dentigerous cyst, soft swelling of the gingiva
eruption cyst
NAME THAT CYST: separation of follicle from the crown of an erupting tooth (primary or permanent)
eruption cyst
most common teeth affected by eruption cyst
- primary central incisors (MC)
- permanent first molars
NAME THAT CYST: translucent to blue/purple in color, surface trauma –> blood in cystic fluid
eruption cyst
Why are eruption cysts blue/purple in color?
surface trauma –> blood in cystic fluid
NAME THAT CYST: usually ruptures spontaneously, allowing tooth to erupt
eruption cyst
history of OKC
- recently was called keratocystic odontogenic tumor
- classified as a cystic neoplasm by the WHO in 2005
- now reclassified back to a developmental cysr in 2017
3rd most common cyst of the jaws
OKC
NAME THAT CYST: different biologic behavior and growth mechanism than dentigerous cyst, arises from rests of dental lamina
OKC
NAME THAT CYST: wide age range
OKC
NAME THAT CYST: can occur anywhere, but posterior mandible and ramus are most common
OKC
most common locations of OKC
posterior mandible and ramus
X-ray:
- well defined radiolucency
- unilocular or multilocular
OKC
25-40% of these cysts are associated with an impacted tooth
OKC
OKCs tend to grow in what direction within the medullary bone?
anterior-posterior
NAME THAT CYST: can become very large without any expansion, but can still be expansile!
OKC
Which tends to cause more significant bone expansion? periapical and dentigerous cyst or OKC (of similar size)
periapical and dentigerous cyst
term used for a cyst that occurs in place of a tooth (tooth never developed)
“primordial cyst”
NOT an actual diagnosis, most of these are OKCs when biopsied
“primordial cyst”
Histo:
- thin, uniform epithelial lining (6-8 cell layers thick)
- production of corrugated/wavy parakeratin
- palisaded basal cell layer
- no rete ridges
OKC
tx of OKC (small vs large)
If small: enucleation and curettage
If large: marsupialization/decompression followed by enucleation or resection
complete removal of this is difficult due to thin, friable lining
OKC
adjunctive techniques for tx of OKCs
- peripheral ostectomy
- chemical cautery (Carnoy’s solution) –> somewhat controversial
recurrence rate of OKCs
30%
most recur within first 5 years, so long-term radiographic follow-up necessary
OKC
How long should OKC lesions be followed for?
at least 7-10 years post surgery to detect recurrences
multiple OKCs =
nevoid basal cell carcinoma
another name for nevoid basal cell carcinoma syndrome
Gorlin syndrome
genetics of nevoid basal cell carcinoma syndrome
- autosomal dominant
- mutation of patched (PTCH1), a tumor suppressor gene
- variable expression among family members
- begins developing during puberty
- sun-exposed AND non-sun-exposed areas
multiple basal cell carcinomas of the skin
most common location of basal cell carcinomas of the skin
mid-face
Why is nevoid basal cell carcinoma syndrome called “nevoid?”
because many behave less aggressively (more like a nevus) than traditional basal cell carcinomas
clinical associations with nevoid basal cell carcinoma syndrome (5)
- palmar/plantar pitting
- bifid ribs
- calcified falx cerebri (fold of dura that divides the brain into R and L sides)
- epidermoid cysts of the skin
- enlarged head cuircumference (frontal bossing, hypertelorism)
increased space between the eyes, associated with nevoid basal cell carcinoma syndrome
hypertelorism
NOT a variant of OKC, 2/3 of cases surround the crown of an impacted tooth (usually third molars)
orthokeratinized odontogenic cyst
x-ray: radiolucency, usually unilocular
orthokeratinized odontogenic cyst
most common location of orthokeratinized odontogenic cyst
posterior jaws, mandible > maxilla
In orthokeratinized odontogenic cyst, the cyst lining produces orthokeratin. What does this mean?
no palisading of the basal layer
recurrence is rare (2%) after enucleation/curettage
orthokeratinized odontogenic cyst
a developmental odontogenic cyst that occurs along the lateral root surface of an erupted tooth
lateral periodontal cyst
source of odontogenic epithelium of lateral periodontal cyst
not certain –> dental lamina, REE, rests of Malassez
- asymptomatic, usually an incidental radiographic finding
- adults, rarely before age 30
lateral periodontal cyst
associated teeth are VITAL, helps distinguish from lateral radicular cyst
lateral periodontal cyst
most common teeth associated with lateral periodontal cyst (75-80%)
mandibular premolar/canine area
X-ray:
- well circumscribed radiolucency along the lateral aspect of a tooth root
- unilocular (most)
lateral periodontal cyst
multilocular appearance can se seen with a variant of lateral periodontal cyst called _______
botryoid odontogenic cyst
tx of lateral periodontal cyst
biopsy, enucleation/curretage
Histo:
- thin, nonkeratinized squamous epithelial lining
- focal, nodular thickenings of the lining
lateral periodontal cyst
soft tissue counterpart of lateral periodontal cyst, blue/translucent, fluid-filled
gingival cyst of the adult
- tiny, superficial, keratin-filled cysts
- 2-3 mm in diameter
- usually multiple
- alveolar ridge
- yellow/white, round
gingival cyst of the newborn
gingival cysts of the newborn arise from?
remnants of the dental lamina
50% of newborns but seldom noticed, rupture and disappear spontaneously, rarely seen after 3 months of age
gingival cyst of the newborn
another name for calcifying odontogenic cyst (COC)
Gorlin cyst
most common location of COC (65%)
anterior jaws
maxilla = mandible
COC
can occur in association with odontogenic tumors, especially odontoma
COC
1/3 of COCs are associated with an impacted tooth, but which tooth is most common?
maxillary canine
X-ray:
- well-defined radiolucency
- usually unilocular
- up to 1/2 have irregular calcifications within
- may cause divergence of teeth, root resorption
- 1/3 are associated with an impacted tooth (maxillar
COC
about 10% are peripheral (extraosseous, develop on the gingiva)
COC
tx of COC
enucleation and curettage
histology is characterized by “ghost cells” within the cystic epithelium
COC
altered epithelial cells that have retained their outline but lost their nucleus, may become calcified
ghost cells (associated with COC)
odontogenic origin, but cyst lining has glandular features
glandular odontogenic cyst
- adults
- mandible (75%)
- predilection of anterior jaws
- unilocular or multilocular
- 30% recurrence rate after enulceation/curettage (follow like OKC, some recommend more aggressive tx, resection, for multilocular lesions)
glandular odontogenic cyst
Histo:
- mucous cells, columnar ciliated cells
- microcysts within the epithelial lining
glandular odontogenic cyst
