Genetics can be considered to have a dominant influence in the etiology of malocclusion when a particular trait shows an increased prevalence in families of affected patients compared to the frequencies expected for general population. It is long been known that single genetic defect may lead to different phenotypes,including tooth agenesis,microdontia,ectopic eruption and delayed dental development. Role of genetics in tooth transposition,external apical root resorption, cleft lip and Palate, TMJ disorders and various orofacial syndromes is well documented.