Ameloblastoma

Etiology • A benign, aggressive jaw tumor of odontogenic epithelial (ecto-
dermal) origin; the most common odontogenic tumor after the odontoma
• Incidence of 0.3 cases per million people
Clinical Presentation • Peak incidence during third to fifth decades • 80% occur in the mandible, chiefly in molar and ramus region • Often presents in association with unerupted third molar teeth • May produce marked deformity, facial asymmetry • Extraosseous or peripheral variant arises in gingival tissues of
older adults (fifth to seventh decades) • Typically slow growing, but persistent

Radiographic Findings • Osteolytic or radiolucent with sclerotic, smooth, even borders • May be unilocular to multilocular • Root resorption or tooth displacement may be seen. • Can expand affected jaw in any plane • Cortical perforation may occur.
Diagnosis • Sheets, strands, islands of odontogenic epithelium • Peripheral layer of cuboidal to columnar ameloblast-like cells
enclosing a cell population analogous to stellate reticulum of the enamel organ
• Cystic degeneration common within stellate reticulum component • Several histologic patterns described have no clinical relevance. • A biologic variant, cystic (unicystic) ameloblastoma, occurs in
younger patients; has a less aggressive clinical course and is managed more conservatively
• Malignant variants rarely seen
Differential Diagnosis • Dentigerous cyst • Odontogenic keratocyst

• Odontogenic myxoma • Central giant cell granuloma

Treatment • Varies with subtype, size, location • Solid/multicystic lesions generally require local excision or
resection. • The cystic variant requires local excision, as recurrences may
follow curettage only
Prognosis • Generally good; recurrence rates higher with conservative
treatment • Recurrence rates of up to 15% following marginal resection • Very good prognosis for cystic ameloblastoma • Long-term follow-up necessary