Hyperdontia is an oral condition characterized by having an excess number of teeth. The standard number of primary teeth is 20 and the standard number of permanent teeth is 32. Primary teeth are the first set of teeth that erupt in a person's mouth, generally by the age of 36 months, and are shed by the time the person is about 12 years old. Permanent teeth then take the place of the primary teeth and are usually fully erupted by the time the person reaches 21 years of age. A person who develops more than 20 primary teeth or more than 32 permanent teeth has hyperdontia. The additional teeth are referred to as supernumerary teeth.