odontomes & odontogenic tumors (lab 6)

7/31/2019 Odontomes & Odontogenic Tumors (Lab 6)

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Dent 356-11 Laboratory Session 5

Odontomes & Odontogenic Tumors

Dr. Rima SafadiModified from Dr. Huda Hammad


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Complex Odontome: Radiographic Features


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Compound Odontome: Radiographic Features
http://www.aichi-gakuin.ac.jp/~radio/Teaching%20file/JB028.jpg/03e.jpghttp://www.aichi-gakuin.ac.jp/~radio/Teaching%20file/JB028.jpg/02e.jpg


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Compound Odontome: Radiographic Features


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Compound odontome

Prof. JH, U of Iowa/USA

pulp


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Complex & Compound Odontomes:Histopathological Features

Complex odontome:

Mass of irregularly arranged,well-formed enamel, dentin,pulp & cementum surroundedby a fibrous capsule.

Compound odontome:

a number of separatedenticles embedded in fibroustissue.


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Complex & Compound Odontomes:Histopathological Features

Both developing complexand compound odontomescontain varying amounts ofodontogenic epithelium

and structures resemblingenamel organs.

They show all stages ofodontogenesis and may be

difficult to differentiatefrom ameloblastic fibromaand ameloblastic fibro-odontoma.


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Ameloblastoma: Radiographic Features

Most commonly appears as a multilocularradiolucency.

Root resorption of involved teeth.


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Ameloblastoma: Radiographic Features

May be associatedwith an uneruptedtooth, particularly animpacted 3rd molar.

The appearance thenmay mimic adentigerous cyst.

Less frequently, itmay present as aunilocularradiolucency.
http://www.usc.edu/hsc/dental/opfs/OT/008bb.html


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Ameloblastoma



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AmeloblastomaProf. JH, U of Iowa/USA

Squammetapl

ameloblasts

te reticulum like cells


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stroma

Odontoge


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Could be arising from cyst wall


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Ameloblastoma: Histopathological Features

Variable patterns dependingon arrangement of neoplasticepithelium.

Follicular pattern:- Discrete, rounded islands or

follicles, each resembling theenamel organ.- Stellate reticulum like cells at

center, surrounded bycuboidal or columnar cellsresembling ameloblasts.

- Nuclei of peripheral cells are

polarized away from thebasement membrane.

- Islands are separated byvarying amounts offibrocollagenous stroma.


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Follicular pattern: severalchanges can occur within thestellate area, including:

1. cystic breakdown.

2. squamous metaplasia

3. granular cell change.
http://www.usc.edu/hsc/dental/opfs/OT/015bb.htmlhttp://www.usc.edu/hsc/dental/opfs/OT/012bb.htmlhttp://www.usc.edu/hsc/dental/opfs/OT/013big.html


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Plexiform pattern:epitheliumarranged as a

tangled network ofstrands andirregular masses,each showing the

same cell layersseen in thefollicular pattern.


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Ameloblastoma: Behavior

Typical ameloblastomais locally invasive andtumor islands infiltratecancellous marrow

spaces without initiallycausing bonedestruction.

This requires wide

surgical excision withnormal margins toavoid recurrence.
http://www.usc.edu/hsc/dental/opfs/OT/014bb.htmlhttp://www.usc.edu/hsc/dental/opfs/OT/017bb.html


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Unicystic Ameloblastoma

Typically presents in a younger age group than other variants 2nd-3rd decade).

Radiographically, it appears as a well-defined, unilocular radiolucency, usuallyassociated with an unerupted tooth, i.e. similar to dentigerous cyst.

The diagnosis is made only after histopathological examination.

Treatment is conservative, since epithelium in most cases is limited to cyst lumen.

If epithelium infiltrates the cyst wall, it should be treated like typical ameloblastoma.


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Ameloblastoma, UnicysticProf. JH, U of Iowa/USA


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Ameloblastomaunicystic



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Peripheral (Extraosseous) Ameloblastoma

Rare variant whicharises in gingival oralveolar soft tissueswithout involving

bone.

May arise from basalcell layer of oral

epithelium, or fromextraosseous dentallamina remnants.
http://www.srt-psc.com/jsamelo3.jpghttp://conganat.uninet.edu/IVCVHAP/COMUNICACION-E/004/C004F03.jpg


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Ameloblastic fibroma

Young fibrous tissue, part of the tumor


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Ameloblastic fibroma


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Ameloblastic fibro odontoma


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Squamous Odontogenic Tumor

Rare tumor presentingwith tooth mobility.

Radiographicallypresents as a well-circumscribed,semilunar ortriangularradiolucencyassociated with roots

of teeth.

Histologically consistsof islands of benign,well-differentiated

squamous epithelium.


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Ameloblastic Fibroma

Important todifferentiate from

ameloblastoma sinceit is not invasive anddoes not requireaggressive therapy.

Radiographically, well-defined unilocularradiolucency.


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Ameloblastic Fibroma

Proliferating strands ofodontogenicepithelium lying inhighly cellular

fibroblastic tissueresembling dentalpapilla.

Epithelium resembles

that of ameloblastomabut stellate cells aremuch less abundant.
http://www.usc.edu/hsc/dental/opfs/OT/057bb.htmlhttp://www.usc.edu/hsc/dental/opfs/OT/056bb.html


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Adenomatoid Odontogenic Tumor

Well-definedradiolucency, may

have radiopacities.often associatedwith uneruptedtooth, simulating

dentigerous cyst.


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Adenomatoid Odontogenic Tumor

Well-encapsulated, solid orcystic.

Sheets, strands, masses ofepithelium which in some

places forms duct-likestructures lined bycolumnar epithelium.

Small foci of calcification

and occasional dentin andenamel matrix may beseen.


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AOT, odontogenic epithelial tumor


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AOT


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AOT


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Odontogenic Fibroma

Odont. Epith remenants


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COCProf. JH, U of Iowa/USA


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COCDr. John Hellstein, UIOWA

COC


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COCProf. JH, U of Iowa/USA


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Ghost cellsCOCProf. JH, U of Iowa/USA

CEOT


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CEOTProf. JH, U of Iowa/USA


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CEOTProf. JH, U of Iowa/USA calcifications

Odont. Epith. Cellsprominent intercel


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CEOT



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CEOT


calcification

Amyloid like material

Odontogeni

Od t i M Cli i l &


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Odontogenic Myxoma: Clinical &Radiographic Features

Multilocualrradiolucency,

soap-bubble, or

tennis-racketappearance, oftenwith well-definedmargins.

Root resorption.


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Odontogenic Myxoma: Histopathological Features

Nonencapsulated immatureodontogenic connectivetissue (not very fibrous)rich in ground substance.

Inactive rests ofodontogenic epithelial cellssurrounded by maturefibroblasts with delicatecytoplasmic processes.

May contain variableamounts of collagen, hencethe term myxofibroma.


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Odontogenic Myxoma


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Cementoblastoma

A rare, benign, well-circumscribed neoplasm ofcementum-like tissuegrowing in continuity withthe apical cemental layerof a molar or premolar thatproduces expansion ofcortical plates and pain.

Identical to osteoblastomaexcept for association with

tooth roots.

Cementoblastoma


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CementoblastomaProf. JH, U of Iowa/USA


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CementoblastomaProf. JH, U of Iowa/USA

Tumors of Debatable Origin:


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Tumors of Debatable Origin:Congenital Epulis


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Congenital epulis

Granular cells


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MNETI

odontomes & odontogenic tumors (lab 6)

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