The development of an occlusion must be considered to be a result of the interactions between genetics and a number of external and internal environmental factors, including the orofacial functions.
Our follow-up study during the years of growth and development determined that morphological malocclusion traits scores were almost the same, while the functional malocclusion score decreased significantly. In the early period of dental development the morphological severity score is related to the stage of dental development, while at a later period, malocclusion severity score is also the result of incorrect orofacial functions at an early stage of dental development.