RADIOGRAPHIC APPEARANCES OF BENING

ODONTOGENIC TUMORS OF THE JAWS

Tumors derived from odontogenic tissues constitute an unusually

diverse group of lesions. These tumors are formed due to aberration from

normal pattern of complex process of development of dental structures

which is called as “Odontogenesis”.

Benign tumors are new growths that are resembling the tissue of its

origin. These tumors typically demonstrated an insidious onset, slow

growth, a frequently well defined mass of regular and smooth outline, a

fibrous capsule and displacement of adjacent normal tissues. They are

usually painless and does not metastasis. Most bening lesions do not

endanger life unless they develop in an area that interferes some vital

function of the organ.

- Since painless, these tumors, many are discovered during routine

radiographic examinations.

- Or found an radiographs obtained no investigate swelling or mass

observed by patient, suggested by history and physical examination.

- Any few benign tumors infiltrate or invade the adjacent normal bone

beyond radiographic tumor margin. Example, ameloblastoma –

which is a locally aggressive lesion, and tend to occur, because of

incomplete removal surgically.

Radiographic Appearances: Appearance of tumor on radiograph

gives:

- Evidence of type of tumor.

- Sometimes provide specific diagnosis.

- Benign either aggressive or non-aggressive.

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Along with the radiographs, final diagnosis is mainly made by

correlating with other data from clinical, h/p and laboratory tests.

- Radiographs provide inflammation of tumor. Mainly location 30

anatomic relationships, radiodensity, size, shape, architecture of

tumor tissue, configurations of lesional borders, effect of lesion on

adjacent structures.

- Designation – benign / aggressive benign / malignant.

- Specific anatomic prediliction – location, example, odontogenic

lesions occurs in the alveolar process where tooth formation takes

place.

- Radiolucency of benign tumors – lends evidence to behaviour of

tumor.

- Benign tumors may be : - Radiolucent

- Mixed radiolucent and radiopaque

- Radiopaque

- Lesions with internal calcification in terms of calcified fleeks, septa,

patterned compartments are usually benign lesions. (Usually due to

organized biochemical process).

- In radioluscent lesions – other tentors such as shape border

configuration.

- Regularity in shape – round or oval well defined borders and benign

lesions.

- Benign lesions : - Often encapsulate.

- Gradual enlargement.

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- Hence tumor border are smooth and

radiographically well defined.

- Effect on adjacent tissues – benign tumor excess pressure resulting

in displacement of teeth or bony cortices.

- Root resorption – benign tumors – resorption of teeth in a smooth

fashion and any along the adjacent edge of tumor.

- Malignant tumors – surround entire root if resorption occur –

specified appearance of roots some times no resorption.

WHO – Histologically typing of odontogenic tumors. First published in

1971. In which major categories under which classified are:

1. Neoplasms and other tumors related to odontogenic apparatus

- Benign

- Malignant

2. Neoplasms and other tumors related to bone

- Osteogenic neoplasms.

- Non-neoplastic bone lesions.

3. Epithelial cysts

- Developmental

- Inflammatory

4. Unclassified lesions.

Benign tumors related to odontogenic apparatus on:

1. Ameloblastoma.

2. CEOT.

3. Ameloblastic fibroma.

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4. AOT.

5. Calcifying odontogenic cyst.

6. Dentinoma.

7. Ameloblastic fibro odontoma.

8. Odontoameloblastoma.

9. Complex odontome.

10. Compound odontome.

11. Fibroma (Odontogenic fibroma).

12. Myroma (Myofibroma).

13. Cementomas - Benign cementoblastoma (true cementum)

- Cementifying fibroma.

- Periapical cemental dysplasia.

- Gigantiform cementoma.

14. Melanotic neuro-ectodermal tumor of infancy.

WHO – Histological typing of odontogenic tumors, 2nd edition 1992

Classified mainly as:

1. Neoplasms and other tumors related to odontogenic apparatus

o Benign

o Malignant.

2. Neoplasms and other lesions related to bone.

o Osteogenic neoplasms.

o Non-neoplasmic bone lesions.

o Other tumors.

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3. Epithelial cysts.

o Developmental.

o Inflammatory.

Classification:

Neoplasms and other tumors related to odontogenic apparatus:

1) Benign

A) Odontogenic epithelium without odontogenic

ectmesenchyme.

- Ameloblastoma 338

- Odontogenic tumor 276

- CEOT 308

- Clear cell odontogenic tumors 403 T

B) Odontogenic epithelial without odontogenic

ectomesenchyme with or without dental hard tissue formation.

- Amaloblastic fibroma 298

- Amelofibrodentinoma (davinoma) 323 and amelofibrio-

odotoma 315

- Odontoameloblastoma 322

- AOT 312

- Calcifying odontogenic cyst 306

- Complex odontoma 318

- Compound odontoma 318

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C) Odontogenic ectomesenchyme with or without

odontogenic epithelium

- Odontogenic fibroma 371

- Mynoma (odontogenic myofibroma) myxaria 347

- Benign cementoblastoma 547 (Cementoblastoma true

cementures).

2) Benign Odontogenic Tumors

A) Ectodermal tumors

1. Enameloma.

2. Ameloblastoma.

3. CEOT 426

4. AOT 289

5. Squamous odontogenic tumor

B) Mesodermal tumors

1. Peripheral odontogenic fibroma.

2. Central odontogenic fibroma.

3. Odontogenic myxoma.

4. Periapical cemental dysplasia.

5. Central cementifying fibroma.

6. Benign cementoblastoma.

7. Giagantiform cementoma.

8. Dentinoma (Ameloblastic fibro dentinoma)

C) Mixed tumors

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1. Ameloblastic fibroma

2. Ameloblastic fibrodentinoma.

3. Odontoma.

4. Ameloblastic odontoma. 329. 446.

D) Terafoma

Radiographic Appearance

Ameloblastoma – (Adamatinoma, Adamontoblastoma. Multiocular cyst)

Features : Recognized by 1827

Histologically benign ameloblastoma 3 types.

o Classic.

o Malignant.

o Mural

o Malignant ameloblastoma – ameloblastic Ca

- It is a benign, locally aggressive infiltrative odontogenic lesions and

true neoplasm of enamel organ.

- Develop in any age – average age 32-33 years.

- Slight perpendicular in men – 1:1 – 1 ratio.

- Slow growth.

- Site post mandibular.

- Signs and symptoms - Pain and discomfort – 26%.

- Ulceration or fistula – 29%

Others - Tooth mobility, paraesthesia

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- Purulent anchorage, trismus

- Treatment – surgical intervention.

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Radiological appearance:

- Classically describial multiocular, expansite radioluscevery.

- Site – mandibular molar / ramus area.

- Archtypical multiocular lesion.

- Location – mandibular 85%

Molar region – 97%

Extension into ramus – 62%.

Included symphyseal region – 29%.

Only one case – acute mandibular

- Ameloblastoma begin as unilocular lesions and evolve into

multiocular lesions.

- Mean age for unilocular lesions 26 years.

- Mean age for unilocular lesions 26 years.

- Mean age for multilocular lesions – 38 years.

- 75% of ameloblastomas in younger people (< than 20 years) are

unilocular.

- Locutes – less than 1cm, numerous resembling honey comb.

- Larger locules – fewer, soap bubble.

- Uneo 1986 – 97 cases – 47% unilocular

37% multilocular

16% soap bubble.

- Buccal and lingual expansion of cortex invariably present

(distinguishes from dentigerous cyst – mainly buccal expansion).

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- Thinned out cortex – Egg shell like appearance or crackling on

palpation, and sometimes perforations seen.

- Relationship to teeth – Uneo 1986 – impacted tooth invariably 38%

of these 82% third molar.

- Root resorption – 39% cases.

- Resorption knife edge pattern because all adjacent roots are cut off

along single linear plane corresponding to the margin of lesion.

- When no resorption – they extend into lesion rather than straddle it.

Classic description of ameloblastomas (1963)

- Applicable to mandibular lesions.

- Divided into 4 possible radiologic manifestations.

- Radiographic appearances varies according to the stage of

development.

- Early stage lesion well defined, indicative of slow growth,

frequently delineated by a hyperostatic border.

- Larger stage Compartments and septasis.

- Occassionally ameloblastoma forms from epithelial lining of

dentigerous cyst – Mural Ameloblastoma.

- Occlusal radiograph – demonstrates expansion and thinning of

cortical plates.

- Perforation of bone is a late features.

Radiologic features of maxillary ameloblastomas:

- Mainly 3rd molar area, and premolar area – 75-90%.

- Followed by maxillary sinus and floor of nose – 12-24%.

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- Dangerous as they invade into facial structures.

- Increased potential for recurrance.

- 6% are maxillary ameloblastoma.

- M:F – 1.5:1

- Average age – 46 years

- Antral involvement – Destruction of antral wall. Antral cleanliness.

Thickening and lining membrane.

- Usually same features of mandibular lesions.

- Few unilocular lesions.

- Worth (1963) – reported scalloped band of bone resorption could be

seen at margin in most cases in careful examination even though

lesion appeared unilocular.

- Knife edge resorption if maxillary teeth are resorbed.

- Use of CT – in maxillary cases – extension in infratemp, fossa soft

tissue extent of ameloblastoma.

D/D

Squamous Odontogenic Tumor : (Benign epithelial odontogenic tumor)

- First reported in 1975 by Pullon and associates.

- Lesions seem to arise within alveolar bone, between the roots of

teeth, may result from the proliferation of epithelial rests of

malassez.

- Age 65% cases between 19-31 years.

- Average age – (Lider) – 36 years.

- Prediliction for African American.

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- M:F – same.

- Most common sign – tooth mobility – 50%.

- Tooth pain / Tendomess – 25%.

- Treatment – local excision, along with extraction of inv. Ducts.

- No recurrance.

- H/P : Lesion characterized by islands of structure squamous

epithelium in fibrous connective tissue trauma. Acute mistaken for

acanthamatous ameloblastoma or well differentiated epidermide

Ca.

Radiographic features:

60% cases maxilla.

50% cases mandibular pre-molar / molar region.

25-30% cases multiple sites of involvement.

- No single feature in characteristic of reports.

- Strickingly constant features – triangular or semicircular

radiolucency within alveolar bone between roots of several teeth.

- In most reports in mandibular lesions – 3 additional features.

1) One of both of adjacent roots often displaced.

2) Destruction of crestal bone.

3) Most cases – scleronic rim may be this and biopsy out

more frequently – thick and condensed / more diffuse.

- Rarely 1cm beyond apices and involved teeth.

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- In maxillary lesions – More destructive nature; tendency to perforate

through caries and extend to involve the palate, sinus (maxillary),

nasal flar and nasal spine.

- Sometimes multiple sites of involvement.

C.E.O.T. (Pindborg Junor)

- First discussed by pituitary – 1955 1% of odontogenic tumors.

- Origin from odontogenic epithelium from stratum intermedium of

enamel organ or oral epithelium.

- Histologically, sheets of poluhedral cells in which round or avoid

areas filled with homogenous esienophic substance believed to be

amyloid which becomes mineralized forming a pattern of concentric

rings of calcification described by pindborg as Liesegang’s

concentrate banded rings.

Reports lesions associated with CEOT are (dangerous cyst + CEOT),

(AOT + CEOT combined epithelial odontogenic tumor damn and

collapses 1983).

- Mean age 40 years, Range 9-92 years.

- M:F even

- 73% white patients.

- Patients have a painless mass that increases slowly.

- Few cases – pain, rarely – nasal stuffiness, epistoxis, headache.

- Less aggressive hence marginal / wide resection clinically behaves

like ameloblastoma, hence treated like one.

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Radiographically:

- Most characteristic – radiolucency associated with an impacted or

unerupted mandibular 1st or 2nd molar that may be displayed causing

bulge in infection cortex.

- Within radiolucency calcified material clustered at occlusal surface

of inverted tooth.

- Location mandibular : maxillary – 2:1

Premolar – molar area.

Pm : M – 1:3

- Common radiographic presentation – that as dentigerous cyst.

- Well or poorly defined.

- Thick or thin sclerotic margin present along with expansion of

cortex.

- Honeycomb pattern sometimes in part of the lesion.

- Extension towards body rather than ramus.

- Radioopaque fleeks calcified material consists of tiny separate

pinpoints areas of calcification.

- Radiopaque material tend to collapse, with roughened or smooth

outlines and sometimes linear streaks crisscross.

- These streaks appear “Driven Snow” appearances – suggestive of

CEOT.

- Driven snow appearance – indication of vector of growth of tumour

with progenitor end of streak at occlusal surface of displaced tooth.

- Occlusal dustency – Gorlin cyst and CEOT.

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- Sometimes – mineralized material obscuring the impacted teeth.

- Mineralized material at margin of lesion.

- 52% cases associated undoubtedly with unerupted or embedded

tooth or teeth.

10% cases – tooth once had been present at CEOT site.

34% cases – no tooth associated.

- Resemblance with dentigerous cyst but different features

i) Suspected when mandibular 1st or 2nd molar is

impacted or embedded.

ii) Protruberence inferior cortex.

iii) Occlusal clustering to obscure embedded

tooth.

- Gorlin cyst (COC) similar to pindborg different features

o Gorlin cyst rarely associated with unerupted molar mostly

other teeth.

o Hydraulic affect at expanded cortex in G.T.

o GC – rarely locules patient often shows loculation.

o GC – calcification resembling odontoma in patient driven

snow.

- Recurrence present – hence radiographic follow up for 10 years

D/D

Clear cell odontogenic tumor:

- This too is a locally invasive neoplasm, through very few exacytosis

have been reported.

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- Some evidence that they may be more aggressive than

ameloblastoma.

- Same may be frankly malignant – clear cell odontogenic carcinoma.

- Seen more frequently in elderly women.

- Some say that it is low grade malignant neoplasm.

- Radiopgraphically – features similar to benign locally aggressive

lesion as it is low grade neoplasms, very little is known about these

lesions.

AMELOBLASTIC FIBROMA – (Fibrous Adanantinoma, soft mixed

odontogenic tumor, soft mixed odontoma, fibro odomatoblastoma).

- First described by Krause 1891.

- Mixed odontogenic tumor arising from both epithelial and

mesenchymal elements of tooth germ.

- Less common than ameloblastoma, but not rare.

- M:F – 1.1 : 1

- Age – 5-20 years, mean – 15 years.

40% cases children < 10 years

- Presentation – 50% cases swelling in initial sign.

Other findings – Discharge, pain, tenderness, failure of teeth to erupt.

- Treatment – Simple enucleation produced excellent results.

Radiographically:

- 17% cases incidental radiologic findings.

- 73% cases post mandible.

- 15% cases post maxilla.

- 63% in molar region.

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Features:

- Although small lesion – often causes expansion of cortex.

- Usually distinct and well corticated (plain radiographs).

- CT – bone window – thin layer of subperiosteal new bone often

found in burnout areas on pain radiographs characteristic features on

CT, may explain low recurrece rate of tumor.

- 65% cases – multilocular lesion resembles ameloblastoma not much

destruction of expanded cortex.

- Lesion may also resemble lateral periodontal cyst.

- AF – Associated with impacted or unerupted teeths.

- Teeth usually displaced.

- Teeth usually within lesion or at the edge of lesion.

- No evidence of lesion attached to tooth, as in dentigerous cyst.

- No root resorbtion.

Summary of radiologic features:

- In patients with younger than 20 years, cases found in post

mandibular impacted tooth usually present, but not always.

- Tumor large and expansite, resembling dentigerous cyst because an

unerupted tooth is involved.

- Relationship of lesion to tooth not cystic radiologically.

AMELOBLASTIC FIBRODENTINOMA – (immature dentinoma,

fibroameloblastic dentinoma, calcifying fibroodontomablastoma).

- Extremely rare tumor.

- Reported first by field and Allerman – 1942.

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- Shafer – epithelial component proliferates in a neoplastic fashion

along with connective tissue portion of the lesion with dysplastic

dentin being formed.

- C/F Average age 16 years (45-63 years)

- Male : female – 5:3

- Younger age group.

- Associated with unerupted primary incisor or permanent molar.

- Lesions are painless though facial swelling present.

- Treatment – Enucleation recurrence not expected.

- R/F – 1st decade –location maxillary and mandibular anterior region.

- 2nd decade – mandibular molar most common.

- Many cases associated with unerupted tooth.

- Lesion predominantly radioluscent however radioopaque flecks

consisting of calcified dentinoid may be seen within the lesion.

- Lesion demarcated by thin rim of sclerotic lops.

- Multilocular lesion possible.

- Follicular sac of unerupted tooth may be enlarged.

DENTINOMA

- Extremely rare tumor of odontogenic mesenchymal origin.

- Reported initially by Straith in 1934.

- 2 variants – dentinoma and ameloblastic fibrodentinoma

- dentinoma composed of odontogenic epithelial, irregular or

dysplastic dentinoma and immature CT resembling dental papillae.

In addition fibrous CT capsule present.

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- M:F – 5:3.

- Mean age 20 years

- Intraoral swelling of alveolar ridge observed invariably along with

non-eruption of corresponding tooth.

- Treatment by enucleation along with curettage capsule.

- R/F – features similar to odontome.

- Dentinomas follow pattern increasing (of age with posterior

location).

- A homogenous or mottled radioopaque mass with density similar to

dentin.

- Mass – circular, or ovoid and rarely several masses grouped

together.

- Margins of mass – smooth, lobulated, spiked or combination of

these.

- Lesion surrounded by a thin radioluscent line corresponding capsule

and beyond thin in a thin rim of condensed bone. If inferior present

– no thin rim.

- Strong tendency for dentinoma to occur directly over coronal

portion of impacted tooth, usually mandibular molar.

- Dentinoma points same way as impacted tooth, (Strange??)

AMELOBLASTIC FIBROODONTOMA (Odontoameloblastic fibroma)

- Hooker 1967, identified and coined the name for the entity.

- Controversy regarding its being a true neoplasm and some

recommended it to be as hamartoma.

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- Age – younger age group < 20 years.

73% - 15 years age

- M:F – 1.2:1 favoring males.

- Lesion expands slowly without any symptoms.

- Lesion associated with impacted or unerupted teeth.

- Resembling complaints non eruption of one or more permanent

teeth, facial swelling and facial asymmetry.

- Treatment – simple enucleation or curettage.

- R/F – few special features:

1. Occurs in posterior jaws.

2. Odontoma in observed but has more radioluscent component

than odontoma.

3. Associated with impacted tooth.

- Most cases posterior jaws; equal in both jaws.

- 72% of posterior region.

- Pericoronal radiolucency – small to large, expanding into ramus

maintains smooth, well defined cortical outline.

- Central radioopaque area may resemble composite or complex

odontome.

- Consists of non-specific radioopaque flecks distributed throughout

the lesion.

- Sometimes – individual radioopaque structures, very distinct and

non-coalescent with round outlines 1-2mm to 1cm in diameter.

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- Washer like appearance- when odontoma component is recognized

easily, cross section appearance consisting of thick radioopaque rim

(enamel, dentin), with radioluscent center (pulp).

- Associated with impacted or unerupted tooth,

- Increased tooth displacement (even of small size) important

diagnostic features.

ODONTOAMELOBLASTOMA (Ameloblastoma odontoma, odontome

odontoma, soft and calcified odontome, adamontite epithelioma).

- It is clinically aggressive, rare benign odontogenic neoplasm.

- First definitive reports – Kemper and Roof 1944.

- It is of mixed tissue origin, composed of tissues of ameloblastoma

odontoma (compound or complex).

- Age – 5-35 years, Patients < 20 years.

43% first decade.

57% 2nd decade.

- M:F = equal.

- Presentation – painless swelling for several months.

- Swelling usually buccal cortex.

- On palpation – no pain, curettage or enucleation.

Radiographically – challenging aspect of radiologic interpretation

identification of ameloblastoma component.

Location – preferentially according to odontoma component

Compound type – anterior lesions

Complex type – posterior lesion

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- Lesions either small or large.

Small lesions Between teeth, confined to alveolar bone.

Between crest of ridge and apices of teeth

Sclerotic margin usually absent.

Expansion towards buccal aspect.

Odontoma component

Can be in various stages of development

Early lesion – predominantly radioluscent with few RO

flecks.

Mature lesions more radioopaque odontome component

resembling teeth or non sp. Mass complex typed.

Large lesions – Extend beyond apical region

Enlarge more AP direction.

Rarely inv. Of inf. Cortex of mandibular.

May occupy entire quadrant or extend into

ramus.

In maxilla – In maxilla, encroachment skin.

Expansion of cortex present, tends to be in

buccolingual direction.

Expansion of infection cortex rare.

Large lesion – Usually well defined and sometimes may be sclerotic,

although focal areas of perforation present.

- Relation to teeth - Appear associated to one or more impacted or

unerupted teeth when is severely displaced.

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- Adjacent teeths may be displaced

- No resorption of roots.

AOT: (Adenoameloblastoma, Ameloblastic adenomatoid tumor

odontogenic adenomatoid tumor, pseudoadenoma adamantinum).

- Stafne credited for recognizing AOT in 1948.

- Dreibaldt 1907 first described this entity.

- 3% of odontogenic tumors (Regezi).

- Believed to be from primitive enamel epithelial.

- Histologically – tumor surrounded by thick capsule and duct like

structures often containing ameloid in a CT stroma.

- AOT may be seen in one of 2 stages of development:

i) Early radioluscent stage with histologic evidence

of calcification.

ii) Mature stage – characterized by calcification

within the lesion.

- Very typical in presentation.

- Most common in 2nd decade.

- Mean age 18 years.

- M:F – 1: 2

- Growth is slow and progressive.

- Lesion often asymptomatic and discovered only on radiographic

examination.

- Frequent complaint – swelling, very rarely pain.

- May be associated with unerupted tooth (usually canine).

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- On palpation – spongy, cyst like – few thin or hard

- Treatment – simple enucleation – no recurrence.

- R/F – typically seen as pericoronal radiolucency in maxillary canine

region.

- Mandibular canine and premolars also involved.

- Often radioopaque flecks within the lesion.

- 65% of cases maxilla.

- 35% mandibular.

- 50% in maxillary are anterior region.

- 14% in premolar.

- In mandibular 69% anterior region.

27% premolar region.

- Size – 1.5-3cms (large lesion more than tens).

- Well corticated, non scalloped outer margin and sometimes may be

thick.

- This feature may be absent in pass of the lesion.

- In maxilla Slight buccal expansion of cortex

Significant expansion in maidbular.

- In maxilla - Lesions grow preferentially medially towards antrum

and nasal fossa.

- Some times – encroach on antrum, obliteration of antrum, if large

expand orbital floor.

- Radioopaque flecks – evidence of calcification within the lesion

suggests diagnosis

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52% cases – preserve and calcification.

65% cases – detatable radioopaque foci which are faint to

quite dense and radioopaque.

- RO foci may be observed in one area or calcific material may

predominate.

- Calcification arranged in tiny patients, resembling snow – flakes

animal pints, hand or foot print, dough shape, semicircle, group of

dogs.

- Although clumping present – predominant arrangement even

distribution flecks without much variation of size, shape or distance

from each other.

- Unique feature – well defined radioluscent band, free RO flecks

that partly or completely surrounds the periphery of lesion.

- Band refer to capsular space- approx 0.3-0.8cms wide.

- RO flecks – presence may signal lesions maturity and significantly

reduced potentral to grow.

- Relation of teeth – associated with unerupted permanent teeth –

74%.

- Most common – canine (68%).

- Not involving with deciduous unerupted tooth.

- No root resorption.

- D/D – dentigerous cyst – usually does not extend apically beyond

CEJ.

CALCIFYING ODONTOGENIC CYST (Keratinizing / or calcifying

epithelial odontogenic cyst, Gorlin cyst).

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- For discussion – prefer term calcifying odontogenic lesion because

some cases are cysts some are tumors, others contain elements both.

- Cyst accounted 2% most are tumors or mixed type.

- Divided this lesion into 4 subtypes histologically.

Type IA – simple unicystic type – typical Gorlin cyst with or

without dentinoid.

Type IB – odontoma producing type –features of IA but

dental hard tissue consist of compound or complex odontoma

producing type.

Type IC – ameloblastomatoma proliferating type and dental

tissue of dentinoid.

Type II – termed dentinogeric Ghost cell tumor.

C/F – Any age group (often 2nd decade).

- Equal sex distribution.

- Painless, slow growing swelling.

- Enucleation – no recurrence.

R/F – Multiple views preferred

- Location – any where in jaws, equally in maxillary and mandibular.

- COC – developed on right side.

- Most common appearance – cystic radiolucency.

- All lesions showed radioluscency in some aspect of lesion.

- 87% cases – Unilocular

Few cases multilocular

- Expansion of perforation observed in 83% of cases.

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- Shear mentioned lesion may have regular outline with well

demarcated margins or the outline may be irregular with poorly

defined margins.

- There may be admixtures, foodedly thickened, tainned and absent

sclerotic margins.

- RO flecks – calcification in characteric.

- Percentage of calcification – 21% to 39% in various streaks.

- Calcification – resembled tooth like structure in other cases RO foci,

faint, dispersed or rather unidentifiable.

- Additional features which may aid diagnosis.

- RO foci around occlusal or in oral surface of impacted teeth.

- RO material clustered at edge of lesion.

- RO foci resemble complex or compound odontome.

- Impacted is not permanent molar.

- Expanded bone appears perforated.

- Relation to tooth No instance of COC with unerupted molars.

No resorption of root.

Displacement of erupted and unerupted tooth

present.

ODONTOMA : (Odomtome, compound composite odontome, complex

composite odontome, compound odontome, complex odontome).

- Term first coined by Broca 1866.

- Pindborg 1971 – 2 types of odontome:

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i) Compound – malformation in which all dental tissues

are represented and arranged in orderly pattern such

that lesion resembles several or many tooth like

structures.

ii) Complex – malformation in which all dental tissues

are well formed but arranged in disorderly pattern

such that lesion does not resemble tooth structure.

Regezi – 37% compound odontomes.

30% complex odontomes

- Odontomas most common abnormalities of jaws.

- Benign tumor of mixed origin, but now believed to be hamanoma.

C/F : Age 16 years.

54% - 2nd decade.

15% - older than 30 years

- Average age for Compound odontome – 17 years.

Complex odontome – 22 years

- 68% - white patients.

- 31% Blacks.

- 2% other races.

- Male preponderover

- Dentists diagnose mainly by non-exception of permanent tooth or

persistence of primary tooth.

- Other finding mild swelling, displacement of erupted teeth, pain or

pressure.

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- Treatment - Surgical excision.

No recurrence

Impacted tooth may not erupt.

R/F – Not difficult to diagnose

Occur any where in jaw

Common location anterior maxilla.

2/3rd occur in anterior jaws.

60-70% compound anteriority.

Maxillary : mandibular 2:1

60% complex odontome posterior region more in mandibular

Right side prediction in jaws.

Early stages – Odontoma radioluscent radioopaque flecks develop as the

teeth begin to calcify.

- All odontome surrounded by thin radioluscent zone consisting CT

capsule corresponding in all respects to follicle of normal tooth.

- Beyond this area- lesion is surrounded by thin sclerotic line –

corresponding normal tooth crypt.

- Important feature – tendency to cause only mild expansion to

accommodate in bone.

- Only 8% cases – swelling present.

Compound odontome – several tooth like structure.

- Does not exceed diameter of tooth. Occasionally may enlarge.

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- Teeth structures resemble rudimentary teeth, their morpholic

characteristics varying with location in jaws. Example, anterior area

– may resemble tiny incisors.

- On cross section washer like approaches.

- Rudimentary teeth same radiologic density.

Complex odontome – single RO mass with density somewhat more than

bone.

- Usually not exceed diameter of teeth longest complex odontome –

museum at Guy’s hospital in London – 11 ------

- Mass round or ovoid with smooth margins.

- Margins sometimes lobulated or spike like.

- Internal elements – may show mottled appearance – varying

densities.

- Synburst appearance – oderly arrangements.

- Sometimes – odontomes symmetrically bilateral.

Relationship to teeth

- 48% cases associated with unerupted teeth.

- In maxilla seen equally in anterior and posterior impacted teeth less

in premolar.

- In mandibular seen in molar area, followed by anterior region.

- Found between roots of erupted teeth or may cause impaction of

normal teeth.

- Relationship of odontomas to impacted teeth. Complex odontomes:

Complex odontomes – 50% cases above

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31% next to impacted teeth.

19% around the tooth of impacted tooth

Compound odontomes – 60% next to tooth

30% above

10% around

- Sometimes complex odontomes completely surround the associated

unerupted tooth, obliterately it entirely (bright light can be used to

assess).

Cystic odontoma:

- Odontomes may be associated with develop of dentigerous cyst.

- 28% incidence of cystic odontomas – Kangars series.

- Worth – 1963 states – radioluscent area surrounding the mass is

increased when cystic transformation has occurred.

- Cyst may be slightly or much larger than odontome.

- Complex odontome may be in center of cystic cavity or to one side,

sometimes vise versa.

- Odontoma may lie freely in cystic cavity.

- Compound odontomes may also become cystic separation of tooth

like structures suggestive of cystic degeneration.

- Sometimes – infection cystic odontome can cause loss of sclerotic

bone surrounding cystic wall.

- C/F, pain, swelling, suppuration.

ODONTOGENIC FIBROMA

- Lesion has poorly defined parameters.

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- 3 histologically distinct variants.

1. Simple type – resembles dental follicle and has few islands

odontogenic epithelium.

2. WHO type – contains mineralized material (osteoid, cementum

like or dysplastic durm).

3. Granular cell variants of OF also known as granular cell

ameloblastic fibroma.

- Age – mean 34 years, range 11-80 years, average age – 31 years.

- No sex predilection.

- Treatment – Curettages no recurrences.

R/F – Features not described, because lesion is rare.

- Only feature is its propensity to occur in mandibular.

- Molar region more common.

- Lesions extend into ramus (usually posterior extension).

- Moderately destructive lesion.

- Half of cases – multilocular.

- Others – unilocular, irregularity osteolytic or radioluscent.

- Large lesion –expansion of convex no perforation.

- Margins well defined.

- No sclerotic margin.

- Septa no as radioopaque as ameloblastoma.

- Teeth may be displaced.

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Granular cell – all lesions radioluscent, well denervated, circumscribed,

well defined, mostly unilocular.

- Slight displacement of mandibular canal. They do not grow no large

size.

ODONTOGENIC MYXOMA : (Odontogenic fibro myxomia,

odontogenic myxoma fibroma).

Virchow 1863 – first described histologic features.

- First reported – 1947 – Thoma and Goldman

- 3-6% of all odontogenic levers.

- 2-4 times less frequent than ameloblastoma.

- Locally aggressive benign neoplasm.

- Arise from odontogenic mesenchymal elements of dental papilla.

C/F – Rare in young children, less than 10 years and old more than 50

years.

- Mean age – 25-35 years.

- Mandibular lesions 5 years earlier than maxillary lesions.

- 5 years early in male compared to female.

- M:F – 3:2.

- Most lesions grow slowly, without pain. Teeth usually not affected

clinically.

- In mandibular buccal and lingual swelling.

- Maxillary – swelling if sinus not involved. It inv. Less swelling,

exopthalmus, nasal obstruction.

Treatment – Small lesions – curettage.

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Large lesion – resection.

Recurrence 26-32%

R/F : Emphasis on OPG

- Mandibular favoured over maxilla.

- Develops in tooth bearing areas.

- Molars followed by premolar area.

- Mandibular lesions cross midline.

- Maxilla usually inv sinus – 44%.

Radiographic appearance consist of one of the 2 patterns depending

on evolution of tumor.

1st stage – begins with osteoporotic appearance with more prominent

medullary spaces, separated by thin septa of bone.

- Septa thinner and more elongated as tumor infiltrates locally,

forming larger osteolytic areas.

- During this stage – classic appearance.

- Multilocular radiolucency with well developed locules.

- Lobeculae interest at right angles to each other.

- Bony septa forming locules are usually straight, thin, elongated,

lacy.

- Eversole 1980 – said ‘Lichenplanus of jaw.

- Many authors suggested soap bone bubble or honey comb

appearances, but lesions tend to form angular locules resembling

TENNIS RACQUEST.

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- Other shapes – small or large diagnosis, diamonds squares

rectangles, X, Y and V figures.

- Margin poorly defined even in first stage.

2nd stage – Breakout or destructive phase.

- Characterized by loss of internal locules, significant expansion,

perforation of cortex.

- Invasion into surrounding soft tissues.

- In maxillary extension into antrum.

- Early feature in this stage – appearance of septa beyond peripheral

margin of lesion.

- Extending right angles to the margin, thus importing a ‘hair’ brush

or sun burst appearance.

- Odontogenic myxoma may destroy the angle of mandibular but

ameloblastoma almost never does this.

- Relation to teeth breakout phase.

o Root resorption

o Tooth displacement.

o Inv of adjacent teeth rare.

o Knife edge cut of resorption of roots high up with 1/3 of root

remaining.

Extragnathic odontogenic myxoma – very rare, involves somatic tissues.

Isolated cases in parotid, lower lip, cheek and soft palate.

BENIGN CEMENTOBLASTOMA: (True cementoma, cemento-

blastoma).

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- First reported by Norberz in 1930.

- Definite clinical and histologic criteria of lesion.

i) Bulbous growth of cementum on root of tooth.

ii) Tendency to expand bony plates of jaws.

iii) Active histologic appearance.

- This is one of 4 cemental lesions categorized by WHO the other 3

placed under non-neoplastic bone lesions.

- This lesion unique in 2 ways.

i) True neoplasm of cementum and the only

cemental lesion, excluding hypercementosis.

ii) Less uncommon.

- Probably derived from root cementum or CT of PDL.

- Discussion cementum/ cementum like / osseous but believe that

since affected to roots the lesion were benign cementoblastoma.

- Male predilection.

- Age 10-72 years.

- Average age 26 years.

- ½ of tumour – younger than 20 years.

- Common sign swelling 73%, pain 53%, usually low grade and

intermittent.

- Clinically affected teeth are vital.

Treatment - Surgical extraction

R/F – Features of benign cementoblastoma

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i) Intimate involvement with whole tooth root, usually 1st molar.

ii) Early, contentious, radioluscent stage followed by RO stage with

an obscured root outline within the lesion.

- Location – 85% mandibular, 60% mandibular 1st molar.

3 radiologically distinct stages:

1. Uncalcified matrix stage

- Circular radioluscent area at apex of vital tooth.

- Apical 3rd of root seen within the area.

- Half of root length may be resorbed by RL mass.

- RL area surrounded by thick band and reactive sclerotic bone may

be 1-3 mm thickness and rather diffuse.

- 1.5cm diameter during this stage.

- Lasts for several weeks.

2. Cementoblastic stage

- Appearance of radioluscent material in center of lesion.

- Lesion mineralizes and cementum like material may coalase with

central mass with more mineralization at periphery.

- Increased to 3cms, becomes more avoid, with egg like appearance.

- Lesion surrounded by distinct and prominent RL band of

approximately 2mm wide.

- An outer rim of sclerotic bone is a variable finding.

3. Mature stage

- Unlimited growth protection

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- Lesion approaches the inf cortex of mandibular and becomes ovoid

and enlarges along length of the body with minimal expansion of inf

cortex.

- In large lesion outer RL rim and sclerotic margin are variable

features.

- Reported sizes – 0.5 – 8cms.

- Expansion 0.5 cm/yr.

- Mass has mottled appearance with multiple radioluscent areas

within radioluscent mass.

- Roots of inv teeth parnally observed towards apex.

- Displacement of adjacent tooth roots without resorption.

- Buccal and lingual expansion of cortex.

- Characteristic finding – sometimes observed in occlusal view –

‘Radiating spicules of cementoid material emanating from central

area and radiating to periphery giving sunray appearance.

- No inv of lesion of crestal portion of alveolar bone.

- No expansion of inf cortex mandibular.

- Slight bowing late denture in huge lexus.

- Downward displacement of inf alveolar canal may be seen.

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