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Unilocular Periapical RL

Periapical Granuloma
Periapical Cyst
Periapical Cemento-osseous dysplasia (early lesion)

Periapical Granuloma

RL- unilocular
corticated or non-corticated (can be either)

Histology of Periapical granuloma

*inflamed granulation tissue surrounded by fibrous connective tissue wall

Cells involved in periapical granuloma

plasma cells

Periapical Cyst

Has epithelial lining
Most COMMON odontogenic cyst more than 50%
Either inflammatory or developmental
Loss of Lamina Dura at apex
*Non-vital tooth
DX: pulp testing, biopsy
TX: extraction or endo therapy

Differential DX for periapical cyst

periapical cyst and peripical granuloma always go together

Periapical Cemento-Osseous Dysplasia

Benign Bone Tumor
Site: Periapical of Mand. Anteriors
Most common in Middle aged black females

Radiographic findings of periapical cemento-osseous dysplasia

RL Early
Mixed RO Late

Dx: clinical and xray findings
Tx: none necessary

Unilocular Pericoronal Radiolucencies

Dental Follicle
Dentigerous Cyst
Eruption Cyst
Odontogenic keratocyst-OKC
Ameloblastic Fibroma
Adenomatoid Odontogenic Tumor- AOT

Dentigerous Cyst

Most Common DEVELOPMENTAL odontogenic cyst
Comes from reduced enamel epithelium
Always assoc. w/ the crown of an impacted tooth
Site: Mand. 3rd Molars
on xray, appears to meet tooth at CEJ commonly

Tx: Ext tooth and remove cystic tissue

Symptoms of Dentigerous Cyst

Tooth Displacement
Root Resorption

Eruption Cyst

Soft tissue component of dentigerous cyst
Looks like blood blister

Tx: allow tooth to erupt, cyst will resolve

Odontogenic Keratocyst (OKC)

Follows along border of mandible
Doesn't cause expansion
Site: posterior mandible
Can't tell the difference btwn this and dentigerous cyst

Assoc with Nevoid Basal Cell Ca Syndrome

Clinical Findings of Odontogenic Keratocyst (OKC)

Grow anterior-posterior direction
Minimal Bony Expansion
RL-well defined
uni or multilocular
"SOAP BUBBLE" appearance
May be corticated (smooth borders)
Impacted tooth 25-40% of lesions

Tx of OKC

Enucleation and curettage
(remove cyst)

Recurrence rate for OKC

30% at 5 year follow up
Follow up on lesions for at least 7 years post surgery to detect recurrences

Nevoid Basal Cell Cancer Syndrome

Autosomal dominant
40% are new mutations
caused by mutation in tumor suppressor cells
OKC are assoc with this syndrome
*basal cell carcinomas on skin
* odontogenic keratocysts in mouth
Not assoc with a tooth

Clinical Findings of Nevoid Basal Cell Ca Syndrome

Mult basal cell carcinomas on skin
85% ot pts have more than 1 odontogenic keratocusts
Intracranial calcifications
100% of pts have basal cell carcinomas

Things Assoc. with Impacted Teeth

Eruption Cyst
Dentigerous Cyst
Periapical Cyst
Ameloblastic Fibroma
Adenomatoid odontogenic tumor

Ameloblastic Fibroma

Site: Post. Mandible
Assoc with impacted tooth
Expansion and swelling present
Only seen in pts under 20 yrs
Most of the time Unilocular
Corticated rim
Appears multilocular but really unilocular

Differential DX:

Dentigerous Cyst
Ameloblastic Fibroma

Adenomatoid Odontogenic Tumor (AOT)

Arises from enamel organ or dental lamina (or both)
60% occur in kids age 10-19
Females more than Males
Maxilla more than Mandible
No recurrence
Tx: enucleation (ext and remove tumor)

Adenomatoid Odontogenic Tumor on Xray

Well-circumscribed RL
RL with RO flecks
Impacted tooth 75%

Unilocular Interradicular RL (btwn the roots)

Lateral radicular cyst
Nasopalatine Periodontal Cyst
Lateral Periodontal Cyst
Residual Cyst
Odontogenic keratocyst
Central Giant Cell Granuloma

Lateral Radicular Cyst

Located on side of root, not apex
Well defined RL-unilocular
Corticated or non-corticated
Dx: pulp testing, biopsy
Tx: EXT, or ENDO
*Non-Vital Tooth
Re-eval in 6 months and 1 yr.
Recurrence: Rare

Nasopalatine Duct Cyst

Unilocular RL
Will only occur btwn #8 and #9
Has a pear shape
Dx: biopsy
Tx: surgical removal

Symptoms: swelling of ant palate
possible drainage and pain

Lateral Periodontal Cyst

Arises along lateral root surface
Occurs in adults 40-50 yrs
Always assoc with a VITAL TOOTH
90% of time located Mand. canine/ premolar
Just in soft tissue, not in bone
Tx: curettage

Must do a vitality test

Xray appearance of Lateral Periodontal Cyst

Unilocular RL or Multilocular RL
May cause Rooth Divergence
Competely asymptomatic

Residual Cyst

Located in area where tooth once was
unilocular RL
corticated or non-corticated
Dx: biopsy plus extraction history
Tx: surgical removal
Recurrence unlikely

Simple Bone cyst

*Teeth are VITAL
20% of pts have painless swelling
Tends to Scallop btwn teeth
Empty or fluid filled cavity
No epithelial lining
Not a true cyst
Walls lined by thin band of fibrous connective tissue
may be vascular
TX: biopsy with curettage

Xray findings of Simple Bone Cyst

Well-defined RL lesion
Scallops btwn roots and teeth
Vital teeth with little to no root resorption

Multilocular RLs

Central Giant Cell Granuloma
Odontogenic Keratocyst
Myxoma (odontogenic myxoma)
Traumatic Bone Cyst

Odontogenic Myxoma

Young adults 25-30 yrs
Mandible more than maxilla
* Post. Mandible most common
May have some Expansion
If small lesion: asymptomatic
If large lesion: painless swelling
May displace teeth
May cause root resorption

Xray of Odontogenic Myxoma

Multilocular RL
"Soap Bubble" Appearance
Irregular scalloped margins
thin wispy trabeculae arranged at right angles

Odontogenic Myxoma Tx and prognosis

Tx: curettage
Resection of large lesions
Follow-up periodically

Prognosis: 25% recur

*these are aggressive and can come back


Most common on Mand. (can extend into ramus)
Can cause painless expansion
Usually grows in anterior-posterior direction
can also grow bucally-lingually
20% assoc with impacted tooth

Ameloblastoma on Xrays

small lesion: unilocular RL
large lesion: multilocular, "soap bubbles"
May have a honeycomb RL

Tx of Ameloblastoma

Depends on size of the lesion
*small: aggressive curettage or resection
*Large: resection or segmental resection


Central Giant Cell Granuloma

Ave Age: 30
Site: ant. or Post Mandible
Painless Expansile Lesion
Grows inside the bone

Xray findings of Central Giant Cell Granuloma

Well- defined RL
uni- or multilocular
*Most commonly multilocular
with or without corticated rim

Dx: Biopsy
Tx: curettage
corticosterois injections

Differential Dx for ameloblastoma

Lateral/Perio Cyst
Lateral Radicular Cyst

must biopsy


Autosomal Dominant
Age at Dx: 2-5 yrs, mild case 10-12 yrs
*Bilateral expansion of post mandible and ramus
also affects maxilla
Multilocular RL
Corticated lesions
Can continue to grow and cause expansion until sexual maturity; lesions then goes away

Tx: Observe


Vascular malformation
Posterior Mandible
-if in area of inf alv canal, it is inside the bone
uni- or multilocular
"worm hole" appearance
Tx; depends on lesion

Traumatic Bone Cyst

Age:10-20 yrs
Site: premolar/molar region
20% pts have painless swelling

XRAY of Traumatic Bone Cyst

Well-defined RL lesions
Scallops btwn roots of teeth
Vital teeth with NO root resorption

Poorly Defined RL

**Think Cancers**
Periapical granuloma or cyst
Malignant Tumors
*Primary cancers:
Squamous cell carinoma
Osteosarcoma (most common)
*Metastatic Cancers:

Focal Osteoporotic Bone Marrow Defect

One Spot...Radiolucent...larger collection of bone marrow
Site: Posterior Mandible
75% of cases are female
Usually follows extraction
Bone marrow fills in space instead of bone
Poorly defined RL
No sharply defined borders

Tx: biopsy
Biopsy shows:
*Normal hematopoietic marrow
*Normal Bone Trabeculae

no further treatment

xray findings of Osteoporotic Marrow Defect

Poorly defined borders
Fine central trabeculations
Overall RL appearance
Follow pt to observe
Eval with cone beam CT scan
Usually incidental finding

Metastatic Cancer

Most Common Malignancy Within Bone
More than 80% or cases occur in Mandible

Metastatic Cancer of jaw sites of Origin:


Symptoms of Metastatic Cancer in Jaw

Loosening of teeth
A Mass
Tissue proliferating out of an extraction site (very bad sign)

Mixed RO/RL Lesions

Cemento-osseous Dysplasia
Ameloblastic Fibro-odontoma
Calcifying Epithelial Odontogenic Tumor
Calcifying Odontogenic Cyst
Paget's Disease of Bone
Fibrous Dysplasia

Ameloblastic Fibro-Odontoma

Arises from odontogenic epithelium and CT
Only seen in kids under 15 yrs

20% recurrence

xray findings Ameloblastic Fibro-Odontoma

Uni- or multilocular
Impacted tooth
RO Flecks

Calcifying Epithelial Odontogenic Tumor

Age: 40 yrs
Mandible more common than maxilla
Asymptomatic or swelling

Tx: conservative excision
14% recurrence

***This occurs only in adults
otherwise indistinguishable from ameloblastic odontoma

Xray Findings of Calcifying Epithelial Odontogenic Tumor

Diffuse or well-circumscribed
RL or RL w/ radiopacities
*snowflake calcifications
50% Impacted tooth

Calcifying Odontogenic Cyst

Site: Mandible more common than maxilla
Looks like:
Calcifying epithelial odontogenic tumor &
ameloblastic fibro-odontoma

Xray findings of Calcifying Odontogenic Cyst

Unilocular RL with scattered radiopacities
30% assoc with impacted tooth

Can't tell difference btwn OKC(odontogenic keratocyst) and:

Dentigerous Cyst

Can't tell difference btwn Periapical granuloma and:

Periapical Cyst

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