Ameloblastoma is a benign odontogenic tumor characterized by uncontrolled growth and various histopathologic patterns, predominantly affecting the mandible. It presents with slow-growing, painless swellings and can be classified into several types based on its histology and clinical presentation. Treatment options range from conservative approaches like curettage to radical surgical excision, with a high recurrence rate observed, especially with less aggressive treatment methods.

1. AMELOBLASTOMA
PRESENTED BY ,
DEEPTHI P
FINAL BDS PART II
DEPT. OF ORAL AND
MAXILLOFACIAL SURGERY

2. INTRODUCTION
A tumour or neoplasm is defined as ‘an abnormal mass of tissue which is
uncontrolled and uncoordinated with that of the normal tissue and persists in
same excessive manner even after the cessation of the stimulus that evoked the
change.’
-Sir Rupert Willis

3. • Based on origin
1.Odontogenic
2. Non Odontogenic
Based on its nature
1.Benign
2.Malignant
CLASSIFICATION

4. 2017 WHO CLASSIFICATION OF ODONTOGENIC
TUMOURS

5. AMELOBLASTOMA- DEFINITION
"Usually unicentric, nonfunctional, intermittent in growth, anatomically benign
and clinically persistent"- Robinson
True neoplasm of enamel organ type tissue.
Second most common odontogenic neoplasm.
Low grade, basaloid tumour with a variable range of histopathologic patterns,
clinical forms and behaviour.

6. HISTORY
Named as adamantinoma by Louis Charles Malassez because of its histological
similarity with adamantinoma of long bones.
Coined as ameloblastoma by Churchill and Ivey in 1934.
First detailed description given by Falkson in 1879.

7. CLASSIFICATION
Clinical classification
• Conventional/ Multicystic/Solid (most common)
• Unicystic
• Peripheral (extraosseous)
• Pituitary ameloblastoma
• Malignant ameloblastoma
Based on histological type
1. Follicular ameloblastoma
2. Plexiform ameloblastoma
3. Acanthomatous ameloblastoma
4. Granular cell ameloblastoma
5. Basal cell type of ameloblastoma
6. Desmoplastic ameloblastoma

8. ETIOLOGY
• Traumatic episodes: Extraction, cystectomy, fractures
• Infections
• Dietary deficiency: vitamin D deficiency,Lack of protein intake
• Virus infection

9. PATHOGENESIS
Ameloblastoma is believed to be derived from
a) Cell rest of enamel organ, either remnants of dental lamina or Hertwig's sheath, the
epithelial rest of Malassez.
b) Epithelium of odontogenic cysts, particularly the Dentigerous cyst & odontomas.
c) Disturbance to developing enamel organ.
d) Basal cells of the surface epithelium of the jaws.
e) Heterotopic epithelium in other parts of body especially the pituitary gland.

10. CLINICAL FEATURES
Age: 20-40 years
Sex: no significant sex predilection
Race: more common in blacks than in white race.
Site: mandible > maxilla(more than 80% mandible)with in mandible molar
ramus area is affected three times more commonly than premolars & anteriors.

11. SIGNS AND SYMPTOMS
• It starts as a slow growing, painless, hard, non tender, ovoid swelling which often enlarges in size
as it causes little discomfort in early stage.
• Facial asymmetry.
• Mobilty of teeth and exfoliation.
• Ill fitting dentures.
• Pain or paresthesia if impinges on nerve.
• Inability to occlude.
• Ulcerations.

12. RADIOGRAPHIC FEATURES
• Presents a unilocular or multilocular radiolucency in diff forms and shapes.
• 50% multilocular,2% peripheral and 6% unicystic lesions.
• Multilocular radiolucency with compartmentalised appearance due to bony
septa (HONEY COMB or SOAP BUBBLE APPEARANCE).
• Root resorption and tooth displacement.

13. • Small / large unilocular or multilocular lesion may show unerupted
toothBuccolingual cortical expansion( hollowing out)

14. HISTOPATHOLOGY
6 HISTOLOGIC SUBTYPES :
1. Follicular ameloblastoma
2. Plexiform ameloblastoma
3. Acanthomatous ameloblastoma
4. Granular ameloblastoma
5. Basal cell type of ameloblastoma
6. Desmoplastic ameloblastoma

15. UNICYSTIC AMELOBLASTOMA
• Defined as a single cystic cavity showing ameloblastomatous differentiation.
• Age: The patients are younger than those with the solid/multicystic form i.e.
around 20 yrs.
• Sex Predilection: equal.
• Location: 90% occur in the mandible usually in the posterior region.
• Typically surrounds the crown of unerupted mandibular third molar and resembles
dentigerous cyst.

16. HISTOPATHOLOGY
ACKERMANN CLASSIFICATION:
1. Luminal type: the tumor is confined to the luminal surface of the cyst by
fibrous connective tissue partially or totally.
2. Intraluminal: the tumor nodules projects from the cystic lining.
3. Mural: the tumor infiltrates the fibrous cystic wall. (high recurrence rate)One
large expansile.

17. PERIPHERAL (EXTRAOSSEOUS) AMELOBLASTOMA
• Rare type.
• Develops in soft tissue of gingiva and mucosa.
• Non invasive.
Clinical features:
• Younger individuals.
• Mandible>maxilla -In premolar region.
• Appears as a nodule on the gingiva/ mucosa.
• Size 3mm-2cm

18. PITUITARY AMELOBLASTOMA
• Craniopharyngioma/Rathke's pouch tumor.
• Neoplasm involving CNS.
• Grows as a pseudo encapsulated mass in the suprasellar area and destroys pituitary gland.
Clinical features:
• Endocrine disturbances, drowsiness & even toxic symptoms.
Histologically similar to oral ameloblastoma but also contains irregular calcified masses as
well as occasional focu of metaplastic bone or cartilage.

19. DIFFERENTIAL DIAGNOSIS
• Ameloblastic fibroma
• Odontogenic myxoma
• Central giant cell granuloma
• Dentigerous cyst
• OKC

20. INVESTIGATION
• RADIOGRAPHS
• Biopsy
• CT
• MRI
• ultrasound

21. TREATMENT
Treatment options include:
a) Radical & conservative surgical excision.
b) En bloc resection
c) Segmental resection
d) Curettage
e) Chemical & electrocautery
f) Antibiotics
g) Radiation resistant

22. SIMPLE EXCISION/ ENUCLEATION
• In case of peripheral ameloblastoma,simple excision of the lesion is performed. Means removal of the tumor by
scraping it from the surrounding normal tissue.
• Curettage given a cure rate of only 10%.
• 60-90% of recurrence rate.
Complications of curettage:
• Seeding into lungs
• Malignant transformation
• Failure of curettage is probably related to the fact that the nest of tumor cells extend beyond clinical & radiographic
margins of the lesion.
• Therefore impossible to eradicate the lesion by scraping procedure.

23. EN BLOC RESECTION
Means removal of tumor with a rim of uninvolved bone but maintaining the
continuity of jaw.
Frequently used therapeutic measure.

24. SEGMENTAL RESECTION
• Means removal of segment of the maxilla / mandible up to & including hemi section or more.
• Includes hemimaxillectomy & hemimandibulectomy.
• Most Commonly used treatment.
• Least chance of recurrence.
• It is noted that the lesion most likely to recur after segmental resection are those over 5cm.

25. CHEMOTHERAPY
• May be sensitive to platinum agents.
• May have role in improvement in non surgical patients.
• Eg; cyclophosphamide, cisplatin,vinblastine, methotrexate etc.
RADIATION THERAPY
• Ameloblastoma is generally radioresistant.
• Post operatively in patients with gross/microscopic residual diseaseRecurrent disease.
• Patients who are poor candidates of surgery

26. PROGNOSIS
• Simple curettage- 90% recurrence rate.
• Ameloblastoma of maxilla - moreaggressive poor prognosis.

27. REFERENCE
Textbook of oral and maxillofacial surgery third edition – SM BALAJI.
Shafer’s Textbook of oral pathology – 8th
edition.