definition, classification and evaluation of benign tumours ofthe jaw

©M. S. Ramaiah University of Applied Sciences

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Definition, classification and evaluation of benign jaw tumours

-DR. ZEESHAN ARIF


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Contents

• Introduction

• Definition

• Classifications

• Evaluation

• Clinical examination

• Distribution

• Location

• Surface consistency

• Radiographical considerations

• Management


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Introduction

• Tumours or neoplasms are new growths of abnormal tissue in the body.

• They are broadly divided into two groups – benign and malignant

• A benign tumour grows slowly and is usually encapsulated and it enlarges by peripheral expansion,

pushes away the adjoining structures and exhibits no metastasis, however it may be locally

aggressive.

• A malignant tumour, rapidly infiltrates the surrounding tissues, including vital structures and

endangers the life of its host. It also shows metastasis in the distant parts of the body usually through

lymph and blood streams.


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• The tissues involved in odontogenesis are

• Enamel organ

• Dental papilla

• Dental follicle

• Enamel organ is an epithelial structure derived from oral

ectoderm

• Dental papilla and dental follicle : they are considered

ectomesenchymal in nature because they are derived from

neural crest cells.


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• The benign jaw tumours are divided into two broad categories—

i. Odontogenic tumours

ii. Non-odontogenic tumours.

• The human odontogenic structures are formed by the inductive interactions between epithelium

and mesenchyme.

• The formation of these structures begin during 5th and 6th week of intrauterine life and

continues till about 16th year after birth.

• During this long period, there is always a possibility of odontogenic lesions developing from

these tissues; resulting in the development of malformations, hamartomas and neoplasms.


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• A malformation—is not neoplastic, but it can cause a functional or esthetic problem,

because of its size or anatomical site.

• A hamartoma—is a benign lesion composed of a new growth of mature cells on existing

blood vessels. (A lesion resulting from faulty development of the embryo).

• A benign odontogenic cyst or self limiting tumour may show an aggressive or malignant

transformation.

• Management of such a lesion is always surgical.


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Definition

• Embryologic events that initiate and control formation of human odontogenic structures

through a finely regulated series of inductive interaction between epithelium and

ectomesenchyme and failure of this inductive mechanism results in the formation of

hamartomas malformations and neoplasms, collective known as odontogenic tumors.


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Classification

• In 1946, Thoma and Goldman, described a classification of odontogenic tumours, based on the tissue

cell of origin.

• It described the induction effects of one tissue (epithelium) on another (mesenchyme) in the

pathogenesis of odontogenic tumours.

• They put these tumours into 3 broad groups:

• i. The lesions primarily derived from epithelium

• ii. Those originated predominantly from mesenchyme

• iii. A mixed group – both epithelial and mesenchymal tissue


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Classification of odontogenic tumours (Gorlin, Chaudhry, Pindborg – 1961)

• 1. Epithelial odontogenic tumours

• A. Minimal inductive change in connective

tissue (Ectodermal origin)

• 1. Ameloblastoma

• 2. Adenomatoid odontogenic tumour

• 3. Calcifying epithelial odotogenic

tumour – CEOT

• B. Marked inductive change in connective

tissue (Mixed origin)

• 1. Ameloblastic fibroma

• 2. Ameloblastic odontoma

• 3. Odontoma

• 4. Complex odontoma

• 5. Compound odontoma


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• 2. Mesodermal odontogenic tumours

• 1. Odontogenic myxoma

• 2. Odontogenic fibroma

• 3. Cementoma

a. Periapical cemental dysplasia (PCD)

b. Benign cementoblastoma

c. Cementifying fibroma

d. Familial multiple (gigantiform) cementoma (Florid osseous dysplasia – FOD)


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• Kramer, Pindborg, Shear in 1992, revised the classification of odontogenic tumours (WHO).

• This classification is based on embryologic principles, that is, the embryonal inductive

influence that the cells of one tissue exert upon the cells of another tissue.

• In the odontogenic tumours, the tissues are either derived from the ectoderm, namely the

enamel organ or the mesenchyme proper (mesoderm).

• The ectomesenchyme is derived from cells of the neural crest during an early phase in

embryogenesis.


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Classification of benign odontogenic tumours (Kramer, Pindborg, Shear – 1992)

• Odontogenic epithelium without odontogenic

ectomesenchyme

• 1. Ameloblastoma

• 2. Calcifying epithelial odontogenic tumour –

CEOT. Pindborg tumour

• 3. Clear cell odontogenic tumour

• 4. Squamous odontogenic tumour

• B. Odontogenic epithelium with odontogenic

ectomesenchyme, with or without dental hard tissue

formation

• 1. Ameloblastic fibroma

• 2. Ameloblastic fibrodentinoma (dentinoma)

• 3. Odontoameloblastoma

• 4 Adenomatoid odontogenic tumour (AOT)

• 5. Complex odontome

• 6. Compound odontome


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• C. Odontogenic ectomesenchyme with or without inclusion of odontogenic epithelium

• 1. Odontogenic fibroma

• 2. Myxoma (odontogenic myxoma, myxofibroma)

• 3. Benign cementoblastoma (true cementoma)


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Non-odontogenic tumours and fibro-osseous lesions of the jaw bones

• Non-odontogenic tumours

• 1. Central fibroma

• 2. Myxofibroma

• 3. Ossifying fibroma

• 4. Osteoma

• 5. Osteoid osteoma

• 6. Benign osteoblastoma

• 7. Chondroma

• 8. Giant cell granuloma

• 9. Central haemangioma

• 10. Benign tumours of nerve tissue


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• Fibro-osseous lesions

• 1. Fibrous dysplasia of bone

• 2. Cherubism (Inherited fibro-osseous bone disease)

• 3. Ossifying fibroma

• 4. Central giant cell granuloma


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WHO classification of non-odontogenic tumours of the jaws (Kramer, Pindborg, Shear (1992))

• I. Osteogenic neoplasms

• Cemento-ossifying fibroma

• II. Non-neoplastic bone lesions

• 1. Fibrous dysplasia of the jaws

• 2. Cemento-osseous dysplasiasa.

• a.Periapical cemento-osseous dysplasia

• b. Focal cemento-osseous dysplasia

• c. Florid cemento-osseous dysplasia

(gigantiform)

• III. Other cemento-osseous dysplasias

• a. Cherubism

• b. Central giant cell granuloma


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Tumors of odontogenic epithelium without odontogenic ectomesenchyme

Tumors of odontogenic epitheliumwith odontogenic ectomesenchyme

Tumors of odontogenicectomesenchyme with or without included odontogenic epithelium

Ameloblastoma Ameloblastic fibroma Odontogenic fibroma

Calcifying epithelial odontogenic tumor Ameloblastic fibro-odontomaMyxoma

Squamous odontogenic tumor Odontoameloblastoma Cementoblastoma

Clear cell odontogenic tumor Adenomatoid odontogenic tumor

Complex odontoma

Compound odontoma

Daniel M. Lasken – Oral and maxillofacial surgery, Vol. 2.


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ECOTDERMAL ORIGIN MESODERMAL ORIGIN MIXED ORIGIN (ECTO+MESO)

Ameloblastoma

Odontogenic myxoma Ameloblastic fibroma

Adenomatoid odontogenic tumor Central odontogenic fibroma Ameloblastic fibro-odontoma

Cementomas-

-periapical cemental dysplaisa

Odontomas -

Calcifying epithelial odontogenic tumor (pindborg tumor)

-familial multiple gigantiform cementoma

- Complex

Squmaous odontogenic tumor -cementofying fibroma -compound

Clear cell odontogenic tumor -Cementoblastoma

Calcifying odontogenic cyst

Burket – histopathological classification


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WHO histological classification 2005

• Benign tumors

• Odontogenic epithelium with mature,

fibrous stroma without ectomesenchyme

– Ameloblastoma

• Solid/multicystic

• Extraosseous/peripheral

• Desmoplastic

• Unicystic

– Squamous odontogenic tumor

– Calcifying epithelial odontogenic tumor

– Adenomatoid odontogenic tumor

– Keratocystic odontogenic tumor


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• Odontogenic epithelium with odontogenic ectomesenchyme with/without hard tissue

– Ameloblastic fibroma

– Ameloblastic fibrodentinoma

– Ameloblastic fibro-odontoma

– Odontoma

• Complex

• Compound

– Odontoameloblastoma

– Calcifying cystic odontogenic tumor

– Dentinogenic ghost cell tumor


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• Mesenchyme and/or odontogenic

ectomesenchyme with/without odontogenic

epithelium

Odontogenic fibroma

Odontogenic myxoma/myxofibroma

Cementoblastoma

• Bone-related lesions

Ossifying fibroma

Fibrous dysplasia

Osseous dysplasia

Central giant cell granuloma

Cherubism

Aneurysmal bone cyst

Simple bone cyst


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• Malignant tumors

a)Odontogenic carcinomas

1 Metastasizing ameloblastoma

2 Ameloblastic carcinoma

• Primary

• Secondary (dedifferentiated) intraosseous

• Secondary (dedifferentiated) peripheral

3 Primary intraosseous squamous cell carcinoma

• Solid type

• From KOT

• From odontogenic cysts

4 Clear cell odontogenic carcinoma

5 Ghost cell odontogenic carcinoma

b)Odontogenic sarcomas

Ameloblastic fibrosarcomas

Ameloblastic fibrodentino-and fibro-odontosarcoma


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Evaluaion


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EXAMINATION AND DIAGNOSTIC METHODS

• Lesions of the oral cavity and perioral areas must be identified and accurately diagnosed so

that appropriate therapy can eliminate the lesions.

• When abnormal tissue growth is discovered, several important and orderly steps should be

undertaken to identify and characterize it.

• When the dentist discovers or confirms the presence of a lesion, the information must be

discussed with the patient in a sensitive manner that conveys the importance of urgent

attention to the problem without alarming the patient.


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History of the Specific Lesion

• Prolonged duration → may be congenital

• Long duration without pain → benign neoplasm

• Short duration, rapid growth→ malignant growth

• Mode of onset and progress

• History of trauma may be obtained in many bone lesions like osteogenic sarcoma. Spontaneous

swelling and rapid growing lesion may be malignant, while very slowly growing lesion may be benign

growth.


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• Exact site and shape

• Progress of the lesion - Whether the swelling has been growing slowly or it has remained stationary

for a long time (benign growth). Has it been growing again after a stationary period of months/years

(malignant transformation in a benign lesion) or has it been continuously increasing in size

(malignant growth)?

• Change in character of a lesion Whether there are ulcerations over the lesions? Fluctuation,

softening, etc. are noticed by the patient recently? Whether painless swelling has become painful –

secondary infection may have set in the lesion.


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• Associated symptoms Pain, abnormal sensations, anaesthesia, paraesthesia over a region, dysphasia,

nasal obstruction – breathing difficulty, tenderness, lymphadenopathy.

• Trismus

• Loss of body weight Malignant growth

• Recurrance

• Habits


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Clinical Examination of the Lesion

• i. Number – whether single or multiple

• ii. Size

• iii. Site– palatal swellings may have salivary gland origin

• iv. Shape and size of the lesion – whether ovoid, spherical, localized, diffuse, etc.

• v. Colour of the lesion – whether red or purple (haemangioma), blue (ranula)

• vi. Surface – whether smooth, lobulated (Benign) or irregular, ulcerated, fungating growth

(malignancy)

• vii. Whether it is pedunculated or sessile?

• viii. Skin over the swelling – red, hot skin will suggest secondary infection


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General considerations

• These tumors usually are painless and most of them do not metastasize unless they are malignant

and are not life threatening unless they interfere with a vital organ by direct extension.

• They represent a new un co-ordinated growth Few spread by direct extension and few by metastases

when they turn malignant.

• Odontogenic tumours are detected usually by enlargement of jaws or are found during radiographic

examination

• They tend to resemble the tissue of origin histologically

• They are insidious on onset and grow slowly


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• OT are generally slow by formation of additional internal tissue because of this the radiographic

borders of benign tumors appear relatively smooth, well defined , sometimes corticated

• OT have more of female predilection with 1:3 of male : female ratio

• Age distribution is according to the type of odontogenic tumour roughly includes 1st to 7th decade of

life


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Distribution

•In children

Variant ameloblastoma

Cherubism

Squamous odontogenic tumor (<15)

Fibrous dysplasia

Odontoma


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< 30 years

•AOT (Peak 16yrs)

Ameloblastic fibroma (peak 16yrs)

Cementoblastoma (25yrs)

Aneurysmal bone cyst (<20yrs)

Cementifying fibroma (<20yrs)

CGCG- 60%< 20yrs

Fibrous Dysplasia < 20yrs

Odontogenic myxoma

Pindborg tumor <20 yrs

Ossifing fibroma

Osteoblastoma

Odontoma


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> 30 years

•Ameloblastoma

Pindborg’s tumor

Odontogenic fibroma

Odontogenic myxoma


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> 40 years

•Ameloblastoma

Ossifying fibroma

CEOT

Odontogenic carcinoma

Odontogenic sarcoma


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Location

• Site of the tumor is of striking importance when it comes diagnosis of OT

• Most of the odontogenic tumors are found in maxilla than that in the mandible


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In the mandible

• Ameloblastic fibroma

• Cementoblastoma

• Odontogenic myxoma

• CEOT

• Central Giant Cell Granuloma

• Metastatic OT

Pre molar and molar region


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Molar and ramus region

• Odontogenic

fibroma

• Cementoma

• Ameloblastoma

• Cherubism

• Aneurysmal bone cyst

Molar and ramus region of the

mandible


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• Odontogenic myxoma

• Gigantiform Cementoma

• Odontogenic fibroma

• Dentinoma

• AOT

• Compound odontoma

• Fibrous dysplasia

• Ossifying fibroma

• Cemntifying fibroma

•Maxilla

•


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• Torus

• Minor salivary gland tumor

• Median anterior maxillary cyst

• Traumatic bone Cysts

• Ewings sarcoma

differentially diagnosed as :


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Surface consistency

Smooth - Benign and malignant mesenchymal origin

Differential diagnosis

Cysts

Space abscess

Benign minor salivary glands

Traumatized lesions

Retention cyst


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•Rough surface - Exophyticmalignant odontogenic tumors


Verrucous carcinoma

Ulcerative Ca

Seborrheic keratoses


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Palpation •Surface temperature

Anatomic region and planes involved

Mobility

Extent

Borders

Shape and size

Thickness of the overlying tissue

Consistency

Fluctuance


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Bony hard consistency

• All calcified OT•Odontogenic

tumors

• Osteomas ,chondrosarcoma

• Exostoses ,pleomorphic adenoma

• Osteosarcomas,Differential


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Pain

• The clinical features of most benign odontogenic tumours are nonspecific

• Benign odontogenic tumours show slow expansive growth with no or slight pain

• In contrast, pain is the first and most common symptom followed by rapidly

developing swelling in nearly all malignant odontogenic tumors.


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•

Painless

Benign OT(commonly)

Cysts

Hematomas

aneurysms

Tender Benign OT Associated

with tooth

Malignant OT

Infection

Mild trauma

Early hematomas

Painful Infected tumors

Malignant OT

Extensive tumors

Chondro sarcomas

Infected cyst

Acute inflammation

Acute infection



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Radiographic considerations

• position

• size

• shape

• presence or absence of lesional calcifications

• estimation of soft tissue volume in relation to calcified tissue

• cyst formation

• impingement on or inclusion of vital anatomic structures,

• displacement of teeth or root resorption

• boundaries between lesion and bone


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Radiographic examination

a cyst usually appears as a radiolucency with sharp borders


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a radiolucency with ragged, irregular borders might indicate a malignant or more aggressive lesion


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General radiographic features

• Benign lesions : Often encapsulate.

• Gradual enlargement.

• Hence tumor borders are usually smooth and Radiographically well defined.

• Effect on adjacent tissues – benign tumor exerts 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 occurs –some times no resorption.


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• Odontogenic tumors may be :

• - Radiolucent

• - Mixed radiolucent and radiopaque

• - Radiopaque


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Root resorption displacement non-vital tooth

AOT

Central Giant Cellgranuloma

Granuloma

Odontogenic myxoma

Odontgenic carcinoma

Odontoma

Ameloblastoma

Keratocystic odontogenic tumor

Dentinogenic ghost cell tumor


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Infiltration into bone

•Ameloblastoma

AOT

Odontogenic myxoma

Metastatic tumors

Ameloblastic fibromas

Fibro odonto sarcoma


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Tumor encapsulation

•Ameloblastoma

AOT

odontogenic myxoma

Central Giant Cell Granuloma

Keratocystic odontogenic tumor

Cherubism

Calcifying cystic odontogenic tumor

Primary intraosseous squamous cell carcinoma derived from odontogenic cysts


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Pathological Radiolucency-Contacting tooth

Periapical - Usually sequale of pulpitis

1.Periapical granuloma

2. Radicular cyst

3. Abscess

4.Osteomyelitis

5.Periapical Cementomas

6.Dentigerous cysts


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Radiolucencies- not contacting teeth

Inter radicular: solitary cyst

Lateral radicular cyst

Primordial cyst

Globulomaxillary cyst

Incisive canal cyst

Median mandibular cyst

Osteomyelitis


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Radio-opacities

• Solitary radiopacities not contacting tooth are True intra bony radiopacities:

• a. Tori.

• b. Unerupted, impacted & supernumerary teeth

• c. Retained roots

• d. Focal & diffuse sclerosing osteomyelitis


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Biopsy

• Definitive diagnosis is established after incision,

excision or intraoperative (frozen section) biopsy

• Biopsy technique is selected after careful

assessment of patient & of use of local, sedation or

GA

• Excisional biopsy is performed for completely

calcified lesions

• Intraoperative frozen sections is used to study

questionable soft tissue


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Management • Goals of treatment

• Eradication of lesion with the least morbidity, preservation and restoration of function.

• Depends on

• Growth potential

• Size

• Anatomic location

• Association with vital structures

• Soft tissue involvement


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Surgical treatment

• Curettage

• Cautery (electrocoagulation)

• Enbloc resection

• Resection with continuity defect

• Partial resection

• Total resection

• Reconstruction with bone grafting or appropriate free tissue transfer


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References

• Burket’s - Oral medicine diagnosis and treatment.

• Wood and goaz - Differential diagnosis of oral and maxillofacial lesions

• Daniel M. Lasken – Oral and maxillofacial surgery, Vol. 2.

• James R. Hupp – Contemporary oral and maxillofacial surgery, 6th edition

• Kruger – Text book of oral and maxillofacial surgery

• Contemporary oral and maxillofacial surgery – Neelima Malik


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Thank you

definition, classification and evaluation of benign tumours ofthe jaw

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