The document discusses various classifications of malocclusion and their etiologies. White and Gardiner's classification distinguished between skeletal and dental factors, as well as pre-eruptive and post-eruptive causes. Salzmann's classification defined three stages - genetic, fetal environment, and postnatal environment - that influence malocclusion development. Moyer's classification identified four sites of etiologic variation: the craniofacial skeleton, dentition, orofacial musculature, and other soft tissues. Graber's comprehensive classification divided factors into general (e.g. heredity, environment) and local (e.g. anomalies in tooth number, shape).