The purpose of this study was to determine the possible effects of genetic and environmental factors on dentofacial complex using monozygotic twins.

The study sample was made of 21 pairs of monozygotic twins (14 female pairs and seven male pairs) between 10 and 25 years. Pretreatment lateral cephalograms were used which were traced and digitized, and various landmarks to determine the anteroposterior and vertical proportions were marked. Samples were divided into two groups. The correlation between groups was found by calculating Pearson's product moment correlation coefficients.

The range of the correlation coefficient was from 0.705 to 0.952. Gonial angle showed the highest correlation coefficient (0.952), while saddle angle showed the lowest correlation coefficient (0.705).

The growth and development of craniofacial complex is under mutifactorial control. However, genetic influences do tend to play a dominant role.

By studying identical twins, we can study about the interaction of the environment with the genes and how it affects the growth and development of the body in general and dentofacial complex in particular. By utilizing twin studies, we can identify whether a particular trait, disease, or disorder is influenced more strongly by genetics or by the environment. Success of orthodontic treatment depends on a proper diagnosis of the problem including its etiological factors. Genetic studies let the orthodontists to understand the effects of genetic and environmental factors in the growth and development of dentofacial complex better and allows to prevent or treat malocclusions and skeletal anomalies in better ways.

Manjusha KK, Jyothindrakumar K, Nishad A, Manoj KM. Growth and Development of Dentofacial Complex influenced by Genetic and Environmental Factors using Monozygotic Twins. J Contemp Dent Pract 2017;18(9):754-758.