The objective of this research is to investigate the relationship between selected candidate genes and specific forms of the face (e.g. underdeveloped lower jaws) that often leads to functional and aesthetic problems requiring orthodontic/surgical treatment. The research will recruit individuals with clinically important facial anomalies (i.e. typical orthodontic patients), as well as control participants. DNA samples will be used to analyse and compare genetic differences in candidate genes between the two groups. The possible effects of an interaction between genetic and environmental factors, such as oral habits (e.g. thumb-sucking), will also be investigated. This project will establish a genetic database that can be followed up longitudinally and may substantially improve our understanding of the biological basis of facial growth.