Radiolucent Lesions 1 Flashcards
T/F Cycts are well defined?
True
are cysts radioluscent?
Yes - and well defined
definition of a cyst
fluid filled cavity lined by epithelium and surrounded by a connective tissue wall
where do cyts occur most and why
in the jaw because they can develop from remnants of odontogenic epithelium
clinical features of cysts
swelling, lack of pain (unless secondarily infected or related to non-vital tooth) and can be associated with unerupted teeth, especially third molars
general shape of cyst
rounded or oval – follow shape of surrounding structure so can loo scalloped
think of a balloon
location of cysts
generally located within the boe – anywhere in maxilla or mandible (rare in coronoid process)
odontogenic cyst where?
TOOTH0BEARING regions in the mandible usually ABOVE the inferior alveolar canal
where is non-odontogenic cyst usually? catrgory?
can grow into sinus (non-odontogenic) or arise from soft tissue
- may be below the inferior alveolar canal
what does the periphery of a cyst look like?
well-defined CORTICATED (fairly uniform) thin RADIO-OPAQUE line
*but a secondary infected, or chronically present cyst can change to a thicker, more sclerotic boundary, or make the cortex less apparent
internal features of a cyst
RADIOLUSCENT – long standing cyst may develop more dystrophic calcification
cyst general effect on other structures
slow-growing but can displace other structure – teeth, inferior alveolar canal, expands
can thin coritcal plates and resorb roots of teeth
two examples of odontogenic epithelial tumors
- ameloblastoma
2. Calcifying epithelial odontogenic tuor
4 examples of odontogenic tumors
- odontoma
- ameoloblastic fibroma
- ameloblastic fibro-odontoma
- adenomatoid odontogenic tumor
odontoma is an example of? growth rate?
example of a hamartoma – it stops growing at the same tie as dental tissues
three main breakdowns of Odontogenic Tumors? these are all what?
- Odontogenic epithelial
- mixed odontogenic tumors
- mesenchymal tumors (odontogenic ectomesenchyme)
* THESE ARE ALL BENIGN
three examples of mesenchymal tumors (odontogenic ectomesenchyme)
- odontogenic myxoma
breakdown of non-odontogenic benign tumors
- benign tumors of neural origin
2. mesodermal tumors
benign tumors of neural origin examples
- neurolemoma
2. neurofibroma
general properties of benign tumors
- slow growing
- spread by DIRECT extension, NOT metastisis
- histologically resemble the tissue of origin
- thought to have unlimited growth potential
location of cartilaginous benign tumor
regions where cartilage resides
- condyle, and syphysis
most likely location of benign tumor
posterior mandible
peripheray and shape of benign tumor
smooth, well defined, sometimes but not always corticated round or oval
*more mature art of tumor is in the center – calcification surrounded by soft tissue cpsule
root resoprtion in bengin vs metastic tumor
benign - smooth borders continous with WD lesion
malignant - from the outside , resulting in thinning ‘SPIKED’ roots
root resoprtion more common in malignant or benign?
BENIGN – ameloblstoma, ossifying fibroma, central giant cell granuloma
effect on surrounding structure in benging tumors
exerts pressure on structures – DISPLACEMENT OF TEETH OR CORTICES – faster growin tumors may outpace the ability of the periosteum to lay down more bone –perforation of the cortex or root resorption
what happens to the periosteum as a lesion grows?
as the lesion grows slowly (in benign) it resorbs the endosteal bone surface and the PERIOSTEUM lays down new bone along the outer cortex, thinning but maintaining the integrity of the cortex
4 examples of well-defined, unilocular radiolucencies in a Pericoronal Location
- Dentigerous Cyst
- Odontogenic Keratocyst
- Ameloblatoma
- Ameloblastic Fibroma
synonym for dentigerous cyst
follicular cyst
definition of dentigerous cyst
a cyst that forms around the crown of an unerupted tooth; fluid accumulates between the epithelium and crown of the tooth; an eruption cyst is the soft tissue counterpart of a dentigerous cyst
clinical features of dentigerous cyst
swelling and facial symetry; missing tooth; no pain or discomfort
5% are supernumerary teeth, mostly mesiodens
where does a dentigerous cyst attach
attaches at CEJ
Effect of entigerous cyst on surrounding structures
propensity to resorb adjacent teeth; displaces associated teeth apically
*resorbing adjacent teeth and can displace teeth into the ramus areas and extend into the sinuses - displacing and expanding the walls of maxilla
cysts in the sinus may rain and collapse as with radicular cysts
location of a dentigerous cyst
ABOVE AND AROUND THE CROWN OF AN UNERUPTED TOOTH but can be eccentric ; commonly third molar or canine ATTACHES AT CEJ can grow into maxillary sinus and can extend into the ramus
differential diagnosis for dentigerous cyst
histopathologic appearance is not specific, raiographic and surgical observation of attachment of cyst is important
managment of dentigerous cyst
surgical removal, may include the tooth as well
large cyst may be marsupialized
odontogenic keratocyst disease mechanism and describe
epithelial lining of OKC has INNATE growth potential–(feature of a tumor) but the radiographic and gross appearance of the lesions are cystic in nature, the epithelial lining is keratinized (hence the name) the inside often contains a viscous or cheesy material derived from the epithelial lining
odontogenic keratocyst synonym
OKC
KOT- keratocystic odontogenic tumor and primordial cyst
clinical features of a odontogenic keratocyst
occur in wide age range but typically 2nd and 3rd decades; slight male predominance, can form around unerupted teeth, aspiration may reveal thick yellow cheesy material
high propensity for recurrence
location of odontogenic keratocyst
90% occur posterior to the canines)
posterior body of mandible, posterior maxilla and ramus)
periphery and shape of odontogenic keratocyst
similar to other cysts or may have scalloped outline
internal structure of odontogenic keratocyst
radiolucent - in some cases curve internal SEPTA, multilocular
effect on surrounding structures in terms of odontogenic keratocyst
grows mesiodistally with relatively little B-L expansion
(excet in upper ramus and coronoid process)
can displace and resorb teeth like pushing the mandibular canal inferior as an example - but to a less extent than dentigerous cysts
clinical feature of exapnsion of odontogenic keratocyst in the mandible
little B-L expansion so significant expansion in the upper ramus but little expansion in the body
- despite the large size the lingual and buccal cortical plates of the mandible only slightly expanded
- lack of expansion in b-l direction and cyst scalloping between the roots of the teeth
odontogenic keratocyst may expand where
into the ramus – so potential to perforate into the medial cortex and contact with the medial pterygoid muscle
odontogenic keratocyst differential diagnosis
most likely a odontogenic keratocyst if attaches APICAL TO CEJ or no expansion of the cortical plates or if follicles are IN TACT
management of odontogenic keratocyst
variable surgical treatment, resection, curettage, marsupialization to reduce the size of the large lesions, close attention to remove cyst walls due to recurrence rate
through radiological assessment and follow-up
ameloblastoma - general
BENIGN but LOCALLY AGGRESSIVE
ameloblastomamost common when?
between 20 and 50
average is 50
location of ameloblastoma
molar-ramus of mandible or posterior maxilla
potential of growth for ameloblastoma? implications
may grow very large – posterior maxilla can be problomatic due to orbit an skull location
describe appearance of ameloblastoma
mixed with CURVED, COARSE SEPTATION (CAN BE STRAIGHT)
“HONEY COMBED”
“SOAP BUBBLE”
do ameloblastoma resorb roots?
Yes - they have a strong potential to do this
management of ameloblastoma
surgical resection
- tends to invade bone beyond radiologic appearance ; and high recurrence if not adequately removed
can be treated with radiation if in-operable
ameloblastoma is what type
odontogenic epithelial tumor
ameloblastic fibroma is what type?
mixed odontogenic tumor
ameloblastic fibroma proliferation of?
proliferation of odontogenic epithelium as well as dental papilla
are ameloblastic fibroma a stage of an odontoma
NO — has more growth potential and is a legitimate benign neoplasm
age of ameloblastic fibroma
age 5-20
*think tooth formation but average is 15
ameloblastic fibroma associated with?
crown of unerupted tooth
brief description of ameloblastic fibroma
may be multilocular with indistinct or curved septa
- assocaited with crown of unerupted tooth
what should we think of when we see a younger patient with radiolucent associated with crowns of unerupted teeth
ameloblastic fibroma
differential diagnosis of ameloblastic fibroma?
may not be bale to differentiate between this and dentigerous cyst or hyperplastic follicle
ameloblastoma vs ameloblastic fibroma
ameloblastoma – older age and septa more defined and coarse
what type is a ameloblastic fibro-odontoma?
benign mixed odontogenic tumor
ameloblastic fibro-odontoma differnce to ameloblastic fibroma?
it is just like an ameloblastic fibroma but with SCATTERED COLLECTIONS OF ENAMEL AND DENTIN, varying from small discrete to round pebbles, doughnut or tooth like
age range for ameloblastic fibro-odontoma?
same as ameloblastic fibroma (5-20)
ameloblastic fibro-odontoma associated with?
crown of unerupted tooth
which has scattered small pieces?
odontoma
examples of well defines, unilocular radiolucencies in a periapical location
- periapical inflammatory lesion/ cyst
- osseous dysplasia
- lateral periodontal cyst
radicular cyst is what type
unilocular radiolucencies in a periapical location
- benign
radicular cyst synonyms and disease mechanism
peri-apical cyst, apical periodontal cyst , dental cyst
- epithelial rest cells of malassez are stimulated by a necrotic pulp and inflammatory roducts and undergo cystic degeneration
- thought to grow by osmotic pressure
clinical features of radicular cyst
most comon type in the jaw
ARISES FROM NON-VITAL ASYMPTOMATIC - unless secondary infection occurs
location of a radicular cyst
APEX OF NON-VITAL TOOTH
- cna appear on the mesial or distal surface of a tooth root
60% in maxilla - especially in incisors or canines
periphery and shape of radicular cyst
well-defined corticated border
secondary infection may lead to loss of cortex or more sclerotic border
round, curved
internal and effect on surrounding structure is typical for a cyst
differential diagnosis between radicular cyst and apical granuloma?
may be impossible - but bigger than 2 cm all indicate a cyst
management of radicular cyst
eliminate source of infection , RCT, apical surgery or extraction
bone grows in what dimension around a cyst? implication?
from the outside in
- so from the periphery
- leading to a wheel spoke pattern
Periapical osseous dysplasia general description and occurs in who?
resorption of normal bone, replaced by fibrous tissue and amorphous bone
occurs in MIDDLE AGE - 39 years
- females > males
- blacks> asains>whites
VITAL TEETH
NO PAIN
where are periapical osseous dysplasia located?
peri-apical region and mandibular anterior more
mand ant > mand post > max teeth
what does periapical osseous dysplasia look like?
usually multiple and bilateral RL border of varying width, often surrounded by sclerotic boe and typically round
note the sclerotic bone at the periphery of the lesions in some cases
stages of periapical osseous dysplasia
RL-> mixe-> RO
can grow and cause expansion, thinning and erosion of cortical borders
periapical osseous dysplasia compared to a cementoblastoma
cementoblastoma are completely round
lateral periodontal cyst disease mechanism
arise from epithelial rests in the periodontium lateral to tooth roots
unicystic or small and grapelick cluster
- botryoid odontotgenic cyst
- intra bony counterpart of gingival cyst in adult
clinical features of lateral periodontal cyst
most are small, less than 2 cm in diameter
- if larger the age range increases
location of lateral periodontal cyst
over half occur in the mandible
in mandible usually from incisor to second pre-molar
in maxilla usually from insicor to cuspid
periphery and shape of lateral periodontal cyst
very circular - well defined cortical borders
rare large cysts will be more irregular in shape
internal structure of lateral periodontal cyst
radiolucent, botryoid variety may have multilocular apearance
effect on surrounding structure with lateral periodontal cyst
may efface the lamina dura of the adjacent root and may displace teeth, may have growth pattern similar to KOT
management of lateral periodontal cyst
biopsy or simple enucleation - do not tend to recur
