Hyperdontia is a condition of having supernumerary teeth (i.e. extra teeth which appear in addition to the regular number of teeth).
You may believe this is what has happened to this person however this is not the case!
This person doesn’t have any supernumerary teeth; instead he has quite a few deciduous (baby) teeth left which have not fallen out. This has resulted in his permanent (adult) teeth coming though as well, which leads you to believe he has two rows of permanent teeth!
How many baby teeth do you think he still has, please comment?
(this is NOT a patient of ours)