Genetic Factors Affecting Facial Growth

Malocclusion is the manifestation of complex genetic and environmental interactions on the development of the oral-facial region. Historically, orthodontists have been interested in genetics as a means to better understand why a patient has a particular occlusion, and to determine the best course of treatment for the malocclusion. The application of genetic information in treatment, however, has been hampered by several factors including: 1) the presumption that heritability studies have some clinical relevance to the individual patient, which they do not (Harris, 2008); 2) the presumption that whatever genetic factors may have contributed to the occlusion will also affect how the patient responds to treatment, which they may not; and 3) a lack of understanding to the extent at which genetic factors may interact with environmental factors (such as those created during orthodontic and dentofacial orthopedic treatments) to influence single gene (Mendelian) traits versus “Complex” traits which are more frequently observed in the clinic. (Hartsfield, 2011)