odontogenic cysts 1 & 2 Flashcards
what is the most common cyst of the jaw?
Periapical cysts
Periapical cysts develop due to inflammatory stimulation of _________________
the epithelial rests of Malassez
T/F: Periapical cysts are associated with NON-vital teeth
true
General characteristics of periapical cysts
1) Round-ovoid radiolucency at apex
2) Inflammation through lateral canals may lead to lateral radicular cyst
what are the microscopic features of periapical cysts?
inflamed granulation tissue or fibrous connective tissue
lined by non-keratinized stratified squamous epithelium
what is the treatment/prognosis for periapical cysts?
1) Tx: endodontic therapy +/- apicoectomy, or extraction with curettage
2) Prognosis: Excellent, but routine follow-up is warranted
what is a residual periapical cyst?
a persisting periapical lesion AFTER tooth is removed
__________ are the most common developmental odontogenic cysts
Dentigerous Cysts
what causes Dentigerous cysts to form?
Fluid accumulates between the crown of the tooth and the reduced enamel epithelium, leading to gradual enlargement of the cyst
Dentigerous Cysts are associated with the ________ of an unerupted tooth
crown
When lucent space around the crown is > _____mm, it is considered a dentigerous cyst
greater or equal to 3-4mm
T/F: Radiographic findings for Dentigerous cysts are mimicked by many odontogenic cysts and tumors
True
where are most dentigerous cysts found? what population groups are at the highest risk for developing them?
Most common site: mand. 3rd molar region, followed by max. canines, max. 3rd molars
Most present in the 2nd and 3rd decades
what are the symptoms of Dentigerous cysts?
A) May produce swelling or resorption of adjacent tooth roots
B) Symptoms are usually due to SECONDARY INFECTION
what are the histological characteristics of Dentigerous cysts?
uninflamed fibrous connective tissue lined by a thin non-keratinized stratified squamous epithelium
Some cysts will have a few scattered mucous cells in the lining
what is the treatment for dentigerous cysts?
Removal of the tooth and enucleation of the cyst, decompression of large cysts
Excellent prognosis
A _____________ is a dentigerous cyst that forms in the soft tissue overlying the crown of an erupting tooth
Eruption Cyst
why are eruption cycts referred to as “eruption hematomas”?
Bluish swelling common (bleeding), thus the term “eruption hematoma”
________ cysts are rare lesion, thought to be derived from degenerating tooth bud epithelium
Primordial Cyst
when do primordial cysts develop?
Develops in place of a tooth, before any mineralized material is deposited
T/F: the Clinical/radiographic diagnosis of primordial cysts are based on no history of extraction or surgery in the area
True
Characteristics of primordial cysts:
May arise from any tooth in the dentition
Usually detected as a unilocular radiolucency in the area of a missing tooth, usually a 3rd molar
The majority of primordial cysts have the microscopic features of what other condition?
odontogenic keratocyst (OKC)
What is the treatment/prognosis for primordial cysts?
Tx: Enucleation
Prognosis: Good
when would radiographic follow-up be needed for primordial cysts?
when there is a histologic diagnosis of OKC (odontogenic keratocyst) upon enucleation
T/F: Odontogenic Keratocysts are relatively common, slow growing cysts
FALSE
they are Relatively common, but locally aggressive cyst
keratocystic odontogenic tumor
Odontogenic Keratocysts are associated with what other condition?
nevoid basal cell carcinoma syndrome
what groups are at risk for Odontogenic Keratocysts? what areas of the mouth are most susceptible?
Peak incidence - 3rd decade
Mandible:maxilla - 2:1 ratio
clinical characteristics of Odontogenic Keratocysts:
what locations are favored, what are the symptoms
1) Mandibular lesions usually develop in the posterior quadrants or the ramus
2) Anterior maxilla favored after 60 yrs of age
3) Usually asymptomatic, may produce swelling/discomfort with enlargement
Odontogenic Keratocysts may mimic what other lesions?
dentigerous cyst, residual cyst or lateral periodontal cyst
what % of Odontogenic Keratocysts present as unilocular? what % are multilocular?
what causes these 2 forms?
A) Majority (up to 80%) present as unilocular radiolucencies with well-demarcated margins and a thin sclerotic border
B) Only 20% exhibit the classic multilocular, expansile radiolucent appearance, which is probably related to the size of the lesion
what are the “three histopathological features” of Odontogenic keratocysts?
- uniformly thin epithelial lining - stratified squamous – 6-8 cells thick
- corrugated surface layer of parakeratin
- palisaded, dark basal cell layer
T/F: The connective tissue wall of odontogenic keratocysts is usually uninflamed
True
- When inflammation is present, the histology of the lining epithelium is markedly altered
what is the treatment protocol for Odontogenic Keratocysts?
A) Treatment is controversial and depends on size of lesion
B) With smaller lesion, careful enucleation as a single piece is ideal
C) With larger lesion, decompression followed by enucleation
what is the prognosis/recurrence for Odontogenic Keratocysts?
Prognosis: Guarded. Recurrence rates range from 3-62%
2 recent reports with 5-year minimum follow-up indicated a 40-50% recurrence rate
what condition is caused by a mutation of the PTCH gene?
Nevoid Basal Cell Carcinoma Syndrome
inheritence characteristics of Nevoid basal cell carcinoma syndrome:
Autosomal dominant
extremely variable expressivity
40% are new mutations
what are the craniofacial features of Nevoid Basal Cell Carcinoma Syndrome?
(hint: theres 4)
1) Enlarged occipitofrontal cranial circumference (60 cm or more in adults)
2) Heavy brow ridges
3) Broad nasal root
4) Mild ocular hypertelorism
what are the skin/epithelial features of Nevoid Basal Cell Carcinoma Syndrome?
A) 1-2 mm shallow pits of the palms and/or soles (65%)
B) Milia and multiple epidermoid cysts (50%)
Radiographic findings for Nevoid Basal Cell Carcinoma Syndrome:
1) Lamellar calcification of the falx cerebri (85%)
2) Bifid, fused or hypoplastic ribs (60%)
Odontogenic keratocysts of the jaws occurs in ____% of people with Nevoid Basal Cell Carcinoma Syndrome.
when does this occur?
85%
may develop during 1st decade, but after age 7 years
T/F: A patient is more likely to have Nevoid Basal Cell Carcinoma Syndrome if they have MULTIPLE odontogenic Keratocysts
True
what is the treatment for Nevoid Basal Cell Carcinoma Syndrome?
- genetic counseling
- remove OKCs as needed
- remove BCCs as needed
- patient should use sunscreen and reduce sun exposure to decrease risk of basal cell Ca
what is the Prognosis for Nevoid Basal Cell Carcinoma Syndrome?
Prognosis: Guarded
- Usually the basal cell carcinomas are relatively small and indolent, but this can be variable
- Periodic radiographic follow-up for OKCs
what is another name for odontogenic keratocysts?
keratocystic odontogenic tumors
what are the features of the Basal cell carcinomas that occur during Nevoid Basal Cell Carcinoma Syndrome?
- multiple carcinomas
- occur in unexposed, as well as exposed, skin
- develop at an earlier age (puberty-35 years)
- often show melanin pigmentation
- are usually quiescent, with a few being aggressive
