As to the development of dysgnathias, a multifactorial system must be assumed, the analysis of single components being limited. These conditions are induced by several genes and various exogenous influences. Starting from these statements, the author considers the hereditary and the environmental factors as a dialectical unit, associates the implications of both groups of factors with typical forms of dysgnathias and draws conclusions as to the prognosis of "mainly genetically" and "mainly environmentally" induced dental and occlusal malpositions.
