"Two third tumor": A case report and its differential diagnosis.

Adenamatoid odontogenic tumor (AOT) is an odontogenic tumor with a prevalence of 2.2-7.1%. AOT is a benign, noninvasive, and progressive lesion which is also known as "a two third tumor." As the name suggests the tumor occurs in the maxilla in two third of cases. It occurs in young patients in two third of cases and associated with missing or unerupted teeth in two third of cases. Two third cases are associated with the maxillary canine. Characterized by slow growing, gradually enlarging, painless swelling associated with missing teeth. We report a case of a male patient of age 22 years, with characteristic findings. AOT resembles different odontogenic cysts and tumors which may include dentigerous cyst, globulomaxillary cyst, ameloblastoma, and other entities, hence must be well differentiated. Conservative surgical enucleation is the treatment of choice. Recurrence rate for AOT is 0.2%. Prognosis is excellent when completely removed in toto.