Cementoblastoma- Mixed odontogenic tumor

Cementoblastoma is defined as a neoplasm characterized by formation of sheets of cementum like tissue containing a large number of reversal lines and lack of mineralization at the periphery of the mass or in the more active growth area. Locally aggressive resulting in bony expansion, root resorption, displacement of adjacent teeth, and jaw deformity.

1. Mesenchymalorigin tumors
a-Odontogenicfibroma
b-Odontogenicmyxoma
c-Benign cementoblastoma

2. OdontogenicFibroma
Itisabenignneoplasmderivedfrom
connectivetissueofodontogenicorigin,it
couldariseintraosseouslywithout
odontogenicepithelium(desmoplastic
fibroma)whichisrare,orextraosseously
(peripheralodontogenicfibroma)whichis
relativelycommon.

3. Desmoplasticfibroma:-
Mostlyaffectthemandibleofyoungadult.
Painlessswellingleadtoextensivebone
expansionofaffectedarea.
Radiograph:-similartoameloblastoma.
Histopathology:-acellularhyalinizedconnective
tissueinscarlikepattern.
Treatment:-enucleationwithhighrecurrence
rate.

4. Peripheralodontogenicfibroma:-
Derivedfromoverlyinggingivalepitheliumor
restofdentallamina
Clinically:-focalgrowthofgingivalike
peripheralfibromamaybeindistinguishablefrom
afibrousepulis.
Histopathology:-amixtureofdenseconnective
tissue,(collagenizedfibroustissue)thatseparate
localizedzonesofmyxomatous,&loose
connectivetissue.Smallislandsofodontogenic
epithelium.

7. OdontogenicMyxoma
Itisaspecialtumorforthejawslocally
aggressivearisefrom dental
mesenchymaltissue.Itisinfiltrative
(notcapsulated)benigntumor.
Mostcommonlyinvolvethemandible,
appearasapainlessswellingor
asymptomatic

8. Clinically
Itoccursinyoungagegroup,mostcommonly
involvethemandible,appearasapainless
swellingorasymptomatic.Themaxillarylesion
willariseintothesinuswhilethemandibular
lesionfoundinmolar,premolararea&often
extendintoramus.
Radiograph : resemble ameloblastoma.

10. Histopathology
-Grosslyitisagelatinoustissue,
microscopicallyconsistofascantyspindle
shapeirregularcellswithfinelong
anastomosingprocesses,andamucoidmaterial
&fewcollagenfibers&epithelialrest.The
marginsofthelesionareilldefined&thebone
trabeculaeshowresorption.Somecasescontain
anodontogenicepithelium.

13. BENIGN CEMENTOBLASTOMA
growingincontinuitywithapicalcemental
layerofmolar&premolar,thatproduce
expansionofcorticalplate&pain(whichis
diagnosticfeatureofthistumor)which
becomemoreintenseiftheareaispalpated,
buttheteetharevital.

18. Mixed epithelial & mesenchymal
origin
a-Calcifying odontogenic cyst
b-Ameloblastic fibroma
c-Adenomatoid odontogenic
tumor
d-Odontoma

19. CALCIFYING ODONTOGENIC
CYST
Itoccursatanyageinbothjaws,mostcommonly
inanteriorregion(anteriortothe1stmolar).
Usuallyextraosseouslesionappearasfocal
localizedswellingingingivawhereas
intraosseouslesionproducegeneralized
expansionofbuccal&lingualcorticalplates.

24. Adenomatoid Odontogenic
Tumor
occursbetween(10-19years)atearly
adolescencemorefrequentinfemaleatanterior
maxilla.Itisderivedfromenamelorgan
epitheliumitisbelievedtobeodontogenic
ectomesenchymalinorigin.Itisfrequently
asymptomaticdiscoveredbyradiograph,large
lesionmayproducepainlessswelling.(common
inmaxilla).

29. Itsurroundedbythickcapsule,thecuttingsurface
eithercysticorsolid.Awelldefinedcapsule
encloseeithermassorstrandofepitheliumamong
whichmicrocystic&ductlikestructure,these
microcysticstructuresmaycontainhomogenous
eosinophilicmaterial.Fragmentsofamorphous
cementoidordentinoidcalcificationmaybeseen
betweentheepithelium.

34. Odontoma
Odontomes aredentalhamartomas
containingthecalcifieddentaltissue.
Odontomaisahamartomatouslesionfound
overuneruptedteethcontainingenamel,
dentine,pulpandcementumineither
normaltoothshape(compound)or
abnormaltoothshape(complex).

35. It represents nearly 70% of whole odontogenic
tumors.
Complex odontomais more commonly
occurred in posterior mandible than maxilla,
as asymptomatic swelling.
Compound odontomais more commonly
occurs in anterior maxilla than in mandible and
as a symptomatic swelling either over the
crowns of uneruptedteeth or between the roots
of erupted one.

36. Complex Odontoma

43. Compound Odontoma

49. B-Malignant tumors
Malignant ameloblastoma
Itissimilartohistologicalfeaturesof
ameloblastoma,maygivepulmonarymetastasis
&retainmicroscopicappearanceofprimary
tumorresulteitherfromaspirationor
implantation.
Treatment: local excision.

50. Ameloblastic carcinoma
Histologicallyresemblesameloblastomabut
lossthedifferentiation&behaveinmalignant
way,itspreadsbylymphnode&distanttoother
regionslateron.
Microscopicallyresemble squamous cell
carcinoma & is treated as intraosseous carcinoma
(malignant tumor in jaw). The prognosis is poor
when lymph node is involved.