• DENTIGEROUS CYST & ERUPTION CYST
• OKC & GORLIN‐GOLTZ SYNDROME
• LATERAL PERIODONTAL CYST
• GINGIVAL CYST OF THE ADULT
• CALCIFYING ODONTOGENIC CYST
• CARCINOMA ARISING IN ODONTOGENIC CYSTS

• Also called follicular cyst
• Separation of follicle around the crown of an
unerupted/impacted tooth
• Most common developmental odont cyst

• Encloses the crown of tooth attached at CEJ
• Crowns fully formed
• Cyst develops by accumulation of fluid
between reduced enamel ep and crown

• Most common ‐ lower thirds
• Upper canines ‐ second most common
• Most frequent between 10‐30 yrs
• Can grow to large sizes
• May cause painless expansion bone

• Typically ‐ unilocular lucency
• Never multilocular, or show calcifications
• May displace tooth for a considerable distance
• Root resorption of adjacent teeth possible
• Lucency should be at least 3‐4 mm in diameter,
otherwise enlarged follicle

• Careful enucleation with removal of the

unerupted tooth

• Prognosis ‐ very good

• Primarily
– Unilocular ameloblastoma
– OKC
• Many other lesions may be associated with an
impacted or unerupted teeth
• Hence, biopsy is mandatory

• Also called eruption hematoma
• Soft tissue analogue of the dentigerous cyst
• Blood in the cystic fluid ‐ imparts a purplish or
brown color
• Usually ruptures spontaneously
• Usually no treatment required

• Developmental odontogenic cyst
• Deserves special consideration because of its
specific histopathologic features and clinical
behavior
• Arises from cell rests of the dental lamina

• Usually between 10‐40 yr of age
• Mandible ‐ 60‐80%
• Tendency to involve post body & ramus
• Tend to grow in AP direction within the
medullary cavity without causing obvious
bone expansion
• Multiple OKCs ‐ suspect nevoid basal cell Ca
(Gorlin‐Goltz) syndrome

• Usually well‐defined radiolucency
• Smooth and often corticated margins
• Large lesions, esp in the post body and ramus
appear multilocular
• 25‐40% ‐ unerupted tooth involved

• Thin, friable wall
• Lining composed of uniform layer of
stratified sq ep 6‐8 cells in thickness
• Lining shows thin layer of wavy or
corrugated parakeratin
• Basal layer shows palisaded layer of
cuboidal or columnar darkly staining ep
cells

• High recurrence after treatment
– Due to friable lining
– Or remaining “cystlets”
• Recurrence rate of approx 30%
• Significant number of recurrences may not be
manifested until 10 or more yrs
• Long‐term follow‐up is necessary

Differential Diagnosis
(multilocular)
• Ameloblastoma
• Odontogenic myxoma
• Central giant cell granuloma
• Cherubism

• Hyperparathyroidism

Differential Diagnosis
(unilocular)
• Gorlin cyst or calcifying odontogenic cyst
• Dentigerous cyst (with impacted tooth)
• Lateral periodontal cyst (location)

• Also called Nevoid Basal Cell Carcinoma Syndrome
• Autosomal dominant trait
• Chief features include
– Multiple basal cell carcinomas of the skin
– OKCs
– Rib anomalies
– Vertebral anomalies
– Intracranial calcification

• OKCs ‐ most constant feature, at least 75% of
patients have these cysts
• Cysts are frequently multiple

• Rare developmental cyst < 2% of jaw cysts
• Diagnosis reserved for cysts in the lateral
periodontal region in which inflammatory cyst
or OKC has been excluded

• Asymptomatic, detected on routine X‐ray
• Most occur in the lower canine‐premolar area
• Frequent in 5th ‐7th decade
• No gender predilection

• Well‐circumscribed oval lucency located
laterally to the roots
• Occasionally, multilocular appearance ‐
botryoid odontogenic cysts

Differential Diagnosis
• OKC
• Ameloblastoma

• Common finding ‐ small, superficial, keratinfilled
cysts on alveolar mucosa of infants
• Arise from remnants of the dental lamina
• Disappear spontaneously by rupture into the
oral cavity
• Seldom noticed or sampled for biopsy
• Epstein's pearls, Bohn's nodules found in the
midline of palate or laterally on H & S palate

• Uncommon lesion
• Soft tissue counterpart of LPC
• Derived from rests of the dental lamina
• Striking predilection for lower canine‐premolar area
(60 to 75%)
• Often bluish or bluish‐gray
• May cause a superficial "cupping‐out" of the alveolar
bone

• Non‐neoplastic cyst
• May be associated with other recognized
odontogenic tumors, most commonly
odontomas

• Predominantly intraosseous lesion
• Rarely, peripheral or extraosseous
• Mean age of occurrence is 33
• No gender predilection
• 65% in the incisor‐canine areas

• Unilocular, well‐defined lucency
• Opaque structures within lesion, either
irregular calcifications or tooth‐like, in about
50%

• Characteristically ‐ variable numbers of ghost
cells within the epithelial component
• Ghost cells ‐ altered ep cells with loss of nuclei
but preservation of basic cell outline

• Simple enucleation
• Prognosis is good
• Few recurrences after treatment

Differential Diagnosis
• OKC
• Dentigerous cyst (with impacted tooth)
• Ameloblastoma
• Calcfying Epithelial Odontogenic Tumor (CEOT

• Not cystic
• Designated as dentinogenic ghost cell
tumors, epithelial odontogenic ghost cell
tumors, or ghost cell tumors
• May be infiltrative or even malignant
• Regarded as neoplasms
• Very different prognosis

• Most arise in odontogenic cysts
• Rare – less than 100 cases in literature
• Carcinomatous transformation of the lining
of a cyst may be more common

• Seen in older patients (mean 59 years)
• Pain and swelling ‐ most important
complaints
• Many have no symptoms
• Diagnosis made upon biopsy
• Xray: irregular and ragged margins of a
radiolucency

• Local block excision to radical resection
• With or without radiation/chemo

Epithelial origin

Mixed origin

Mesenchymal origin

– CENTRAL ODONTOGENIC FIBROMA
– PERIPHERAL ODONTOGENIC FIBROMA
– ODONTOGENIC MYXOMA

– AMELOBLASTIC FIBROMA
– AMELOBLASTIC FIBRO‐ODONTOMA
– AOT
– ODONTOMA

– AMELOBLASTOMA
– MALIGNANT AMELOBLASTOMA AND AMELOBLASTIC CA
– CEOT

• Most common clinically significant
odontogenic tumor
• Frequency = combined frequency of all
other odont tumors, except odontoma

• Odontogenic epithelial origin
– Cell rest of enamel organ
– Developing enamel organ
– Ep lining of an odont cyst
– Basal cells of oral mucosa

• Slow‐growing, locally invasive
• 3 types
– Conventional solid or multicystic (86%)
– Unicystic (13%)
– Peripheral (extraosseous) (1%)

• Solid or Multicystic
• Swelling or expansion of jaw
• Most occur in the mandible, in the molarascending
ramus area
• Multilocular lesion ‐ "Soap bubble"
appearance
• Resorption of roots

• Ranges from simple enucleation and
curettage to en bloc resection
• Often extends beyond its apparent
radiologic or clinical margin
• Marginal resection most widely used

• High recurrence rates (50‐90%) depending
on type of surgery
• Recurrence often takes many years

• Younger pts usually during 2nd decade
• Frequency 13%
>90% in posterior mandible, Circumscribed
lucency around the crown of an unerupted
lower 3rd
• Usually treated as cysts by enucleation
• Recurrence 10‐20%

• Uncommon extraosseous variant, 1%
• Most lesions clinically resemble some form of
fibroma
• Innocuous clinical behavior
• Recurrent rate of 15‐20%

• Malignant ameloblastoma: histologic
features of ameloblastoma, both in primary
and metastatic deposits
– Metastases most often in lungs ‐“Aspiration” or
“implant” metastases
– Cervical lymph nodes 2nd most common
location for metastasis

ameloblastoma that has malignant features
– Follow markedly aggressive course
– Metastases do not necessarily occur

• Xray
– M. ameloblastomas similar to normal ameloblastoma
– Ameloblastic Ca: more aggressive
• Histology
– M. ameloblastoma similar to normal ameloblastoma
– Ameloblastic Ca show malignant cytologic features
• Prognosis for both lesions is poor

• Also called, Pindborg Tumor
• Close resemblance to stratum intermedium of the
enamel organ
• Betwn 30‐50 yrs of age
• 75% in mand, mostly posterior
• Unilocular or multilocular lucency
• May contain calcified structures

• Frequently assoc with impacted tooth
• Nuclei show pleomorphism
• May be mistaken for metastatic disease
• Recurrence rate 15%

Clinical features
• Rare,benign od tumor ‐1975 (40 cases)
• Mean age 38y, multifocal reported
• Equal jaw distribution
• Equal sex predilection
• Painless/mild pain ‐ gingival swelling
• Tooth mobility
• Triangular RL (Perio bone loss)

Tx & prognosis
• Wide surgical excision
• Curative
• No recurrence
• Maxillary lesions more aggressive
• 1 report of malignant transformation
• Solitary lesions more aggressive

• True mixed tumor
• Young patients in the first two decades
• Most in post mand in perm 1st/2nd molar
area
• Either unilocular or multilocular
• 50% assoc with unerupted tooth
• Recurrence after conservative excision

• Like AF but with enamel and dentin
• May represent a stage of odontoma
• May cause deformity & bone destruction
• Usually in children around 10 years
• Equal in both jaws
• May prevent tooth eruption

• Well‐circumscribed unilocular (rarely
multilocular) may have calcifications
• May be associated with unerupted tooth
• Treatment – curettage with excellent
prognosis

• Ameloblastic sarcoma
• Malignant – Ameloblastic fibroma
• 50 cases
• M: F, 1.5:1
• Younger, mean 27.5 yrs

• 80% , Mandible
• Pain, swelling , rapid clinical growth
• Ill ‐ defined radiolucency
• Radical surgical escision
• Death is due touncontrolled local disease
• 1 metastasis in 49 evaluated cases

• Limited to younger patients 10‐19 yrs
• Striking tendency for anterior maxilla
• F:M = 2:1
• Circumscribed, radiolucency around crown of
an unerupted canine
• Easily enucleates from bone due to capsule

• Most common odontogenic tumor
• Prevalence exceeds all other tumors combined
• Considered to be developmental anomalies
(hamartomas) rather than true neoplasms
• Divided into compound and complex types

• Seen during the first two decades, mean age
14
• Relatively small and seldom exceed the size of
a tooth
• Frequently assoc with an unerupted tooth and
prevents eruption of the tooth
• Treated by simple local excision

• Composed of multiple, small tooth‐like
structures
• More common in the anterior maxilla
• Presents as a collection of tooth‐like
structures of varying size

• Mass of enamel and dentin, with no
resemblance to teeth
• More often in the molar regions of either jaw
• Presents as a calcified mass with the
radiodensity of tooth structure

• Occurs in adults
• Marked female predilection
• Both maxilla and mandible in posterior region
• Larger lesions may cause expansion or
loosening of teeth

• X‐ray: Well‐defined, unilocular, lucency
– Larger lesions may be multilocular
• Treatment : enucleation and curettage
• Limited growth potential

• Soft‐tissue counterpart
• Firm, slow‐growing sessile gingival mass
• Indistinguishable from other “bump on the
gum” entities
• Seen on facial mandibular gingiva, usually 1.5
to 3.5 cm & may displace teeth
• Surgical excision with excellent prognosis

• Arise from odontogenic mesenchyme
• Young adults, average 25‐30 yrs
• Found in almost any area
• Unilocular or multilocular
• Large myxomas of mand show a "soap
bubble" appearance indistinguishable from
ameloblastomas

• Small lesions by curettage
• Larger lesions by more extensive resection
• Not encapsulated and tend to infiltrate the
surrounding bone
• May recur