Which odontogenic tumour is most common in patients under 20 years of age?

Correct answer: C. Odontoma

• A. The adenomatoid odontogenic tumour does favour young females and the anterior maxilla, but it is much rarer than odontoma.
• B. The calcifying epithelial odontogenic tumour (Pindborg tumour) is rare and presents in middle age.
• C. Correct. The odontoma is by a wide margin the most common odontogenic tumour overall, and it is typically discovered in the first two decades — often as an incidental finding when a tooth fails to erupt.
• D. Ameloblastoma peaks in the third to fifth decades and is far less common, though it is the most common clinically significant one.

Note: Odontomas are now classified as developmental hamartomas rather than true neoplasms. Compound types occur anteriorly, complex types posteriorly.