The odontoma is a hamartoma (benigntumor) of odontogenic origin. The average age of people found with odontoma is 14, and the condition is frequently associated with an unerupted tooth.
Classification
There are three types. Simple, compound, and complex.
The simple can also be classified as a supernumerary tooth, having all the structures, and usually sharing some morphology with teeth in general - separate dentin, enamel, and pulpal structures.
A compound odontoma still has these three separate entities, however may present a lobulated appearance where there is no definitive demarcation of separate tissues between the individual "toothlets".
The complex type is unrecognizable as dental tissues, usually presenting as a radioopaque area with varying densities.
References
Kahn, Michael A. Basic Oral and Maxillofacial Pathology. Volume 1. 2001.