Odontogenic Cysts - part I Flashcards
inflammatory cysts
- periapical (radicular) cyst
- residual periapical (radicular) cyst
- buccal bifurcation cyst
developmental cyst
- dentigerous cyst
- eruption cyst
- primordial cyst
- odontogenic keratocyst (OKC)
- gingival (alveolar) cyst of the newborn
- gingival cyst of the adult
- lateral periodontal cyst
- calcifying odontogenic cyst (COD)
what is the most common cyst of the jaws?
periapical cyst
what is periapical cyst also known as?
- radicular cyst
2. apical periodontal cyst
what causes periapical cyst?
inflammatory stimulation of epithelial rests of Malassez
epithelial rests of Malassez
- PDL
2. clusters of residual cells of Hertwig’s epithelial root sheath
T/F: periapical cyst is asymptomatic
true
what is a a periapical cyst associated with?
non-vital tooth - pulp test!
what happens if periapical cyst is secondarily infected or if large?
may get swelling, pain
radiographic features of periapical cyst
- round to ovoid radiolucency at apex
- loss of lamina dura
- may develop on lateral aspect of root
why might a periapical cyst develop on the lateral aspect of the root?
due to presence of lateral canal in the area “lateral radicular cyst”
histopathologic features of periapical cyst
- inflamed granulation tissue or fibrous CT lined by non-keratinized stratified squamous epithelium
if no cyst lining is seen histopathologically in a periapical cyst, what is it called?
periapical granuloma
tx of periapical cyst
- endo
- apicoectomy
- extraction w curettage
what should be done to confirm healing from periapical cyst?
radiographic follow-up
prognosis of periapical cyst
excellent
what may happen if the periapical cyst is not completely removed?
may persist as a residual cyst
what does residual cyst often represent?
periapical cyst which had not been removed with the extraction or resolved with endo
what is seen in the site of a residual cyst due to previous extraction or endo treated tooth?
well-defined radiolucency
tx of residual cyst
enucleation
prognosis of residual cyst
excellent
who is normally affected by buccal bifurcation cyst?
children
which tooth is typically involved with a buccal bifurcation cyst?
mandibular molars
clinical features of buccal bifurcation cyst
- localized swelling buccal aspect of alveolar process
- ± pain
- possible foul taste
T/F: buccal bifurcation cyst may be hard to detect radiographically
true
radiographic features of buccal bifurcation cyst
- may have well-defined radiolucency in the furcation, superimposed over the roots
- apices typically tipped to lingual cortex
- may see proliferative periostitis
proliferative periostitis
single or multiple subperiosteal layers of bone formation
histopathologic features of buccal bifurcation cyst
inflamed granulation tissue or fibrous CT lined by non-keratinzed stratified squamous epithelium (like periapical cyst)
tx of buccal bifurcation cyst
- enucleation
2. may heal spontaneously
T/F: tooth involved in buccal bifurcation cyst needs to be extracted
false, tooth does not require extraction
prognosis of buccal bifurcation cyst
good
how long does it take for bone to fill in and have normal perio probe depths after tx’ing buccal bifurcation cyst?
~1 year
what may need to be done after tx’ing buccal bifurcation cyst?
recontouring of furcation or periodontal surgery
T/F: involved tooth with buccal bifurcation cyst may be lost due to bone destruction
true
what is the most common DEVELOPMENTAL odontogenic cyst?
dentigerous cyst
what is the 2nd most common cyst overall?
dentigerous cyst
what is the most common cyst overall?
periapical cyst
how does a dentigerous cyst develop?
due to accumulation of fluid between the crown and the reduced enamel epithelium, which eventually forms the epithelial lining of cyst
T/F: dentigerous cyst is usually asymptomatic
true
clinical features of dentigerous cyst
- may have swelling
2. can cause root resorption adjacent tooth
radiographic features of dentigerous cyst is associated with what?
with the crown of an unerupted tooth
radiolucency GREATER than 5 mm is probably what?
a cyst
radiolucency SMALLER than 5 mm is probably what?
hyperplastic dental follice
T/F: a cyst and hyperplastic dental follice are histologically indistinguishable
true
radiographic features of dentigerous cyst
- unilocular
- attaches to cervical area of tooth
- well-defined, often corticated border
what will the dentigerous cyst appear radiographically if it is infected?
borders may appear ill-defined
T/F: any unerupted tooth may have a dentigerous cyst?
true
what is the most common unerupted tooth that may have a dentigerous cyst?
mandibular 3rd molar
list the order of the most to least common unerupted tooth that may have a dentigerous cyst
mandibular 3rd molar > max canine > max 3rd molar
histopathologic features of dentigerous cyst
- uninflamed fibrous CT wall lined by thin, non-keratinized stratified squamous epithelium
- may see scattered mucous cells in lining
tx of dentigerous cyst
removal of tooth and cyst
prognosis of dentigerous cyst
excellent
microscopic exam of dentigerous cyst is needed to rule out what?
other cyst or tumor
the mucous cells in the lining of dentigerous cyst histopathologically may explain what?
central (intraossesous) mucoepidermoid carcinoma
who is affected by eruption cyst?
children
eruption cyst
dentigerous cyst that forms in the soft tissue overlying the crown of an erupting tooth
clinical features of eruption cyst
bluish swelling, “eruption hematoma”
T/F: primordial cyst is common
false, rare
where is primordial cyst thought to be histogenetically derived from?
degenerating tooth bud epithelium
primordial cyst develops in place of what?
a tooth, before any mineralized material is deposited
which tooth can be affected by primordial cyst?
any tooth, including supernumerary teeth
what is mandatory for diagnosis of primordial cyst?
no hx of extraction or surgery in area
radiographic features of primordial cyst
unilocular radiolucencu in area of missing tooth
the majority of primordial cysts have the microscopic features of what?
odontogenic keratocyst (OKC)
histopathologic features of primordial cyst
- corrugated surface
- cyst lined by parakeratotic stratified squamous epithelium
- hyperchromatic and palisaded basal cells
tx of primordial cyst
enucleation
prognosis of primordial cyst
good
what can OKC be associated with?
nevoid basal cell carcinoma syndrome (NBCCS)
what might OKC mimic?
- primordial cyst
- dentigerous cyst
- residual cyst
- lateral periodontal cyst
T/F: OKC is uncommon
false, common
T/F: OKC is benign but more aggressive compared to other odontogenic cysts
true
T/F: OKC is symptomatic
false, asymptomatic
where does OKC favor after 70 y.o.?
anterior maxilla
T/F: there are no OKC cases under 10 y.o. unless pt has syndrome
true
T/F: OKC has a maxilla 2:1
false, mandible 2:1
what is noted at time of surgery for OKC?
“cheesy” material
areas in the jaw most affected by OKC
- posterior mand (49%)
- posterior max (20%)
- anterior max (13%)
- anterior mand (9%)
- mand PM region (7%)
- max PM region (2%)
radiographic features of OKC
majority (80%) unilocular radiolucencies with well-demarcated margins and a thin sclerotic borde
T/F: OKC can hollow-out mandible without expansion
true
T/F: OKC can be expansile and symptomatic
true
a small percent of OKC cases exhibit what radiographically?
multilocular appearance
OKC resembles dentigerous cyst radiographically except what?
the lucency for OKC is apical to the CEJ
3 histopathologic criteria for OKC
- uniformly thin epithelial lining of stratified squamous epithelium 8-10 cells thick
- corrugated parakeratin surface
- palisaded basal cell layer
T/F: OKC histopathologically has CT wall that is not inflammed
true
tx for OKC depends on what?
size of lesion
tx for smaller OKC
enucleate in one piece
tx for larger OKC
marsupialization followed by enucleation
prognosis of OKC
guarded
