Abstract A theoretical presentation concerning the histogenesis of mixed odontogenic tumors in relation to tooth germ embryogenesis is discussed. It is proposed that the individual tumors that make up this group are solely and totally dependent upon the presence of differentiation factors which are or are not elaborated by a particular tumor. The probability of sequential differentiating events resulting in the progression of an immature entity (ameloblastic fibroma) to a highly differentiated entity (odontoma) has been discounted, with reservations. Rather, it is postulated that individual mixed odontogenic tumors arise at comparable stages observed during normal odontogenesis and, as such, are incapable of further differentiation and thus proliferate within the histologic confines of their innate differentiated capacity.