Adenomatoid odontogenic tumor: biologic profile based on 499 cases.

Topographically, the AOT occurs in peripheral and central variants, the latter further in follicular (with embedded tooth) and extrafollicular (no embedded tooth) types. The AOT is slow growing with few or no symptoms. Tumor growth may cause displacement of teeth rather than root resorption. The follicular AOT mimics a follicular cyst, the extrafollicular a residual or "globulo-maxillary" cyst and the peripheral a gingival fibroma. All variants of AOT show identical histologic features. The central variants account for 97.2%, 73.0% of which are follicular. The follicular variant (M:F ratio 1 to 1.9) is three times as frequent as the extrafollicular. The follicular variant is diagnosed earlier in life (mean age 17 yr) than the extrafollicular (mean age 24 yr). 53.1% of all variants occur within the teens (13-19 yr). Follicular AOT is associated with one embedded tooth in 93.2%. Maxillary permanent canines account for 41.7% and all four canines for 60.1% of AOT-associated embedded teeth. Ranking four among the odontogenic tumors the AOT is not a particularly rare tumor. Conservative surgical excision is the treatment of choice. Documented recurrences have not been reported.