Genetic Factors That Affect Asymmetric Mandibular Growth—A Systematic Review

Abstract

Facial asymmetry is a feature that occurs to a greater or lesser extent in the general population. As its severity is usually slight, facial asymmetry may not be noticeable to the patient. However, there are cases when severe facial asymmetry not only affects the facial aesthetics by distorting facial proportions, but also contributes to problems related to the function of the stomatognathic system. The nodal signalling pathway appears to be of particular importance in the process of mandibular asymmetry, as it affects not only structures formed from the first pharyngeal arch, but also other organs, such as the heart and lungs. Following the evaluation of the available literature, the inheritance of mandibular asymmetry is a very complex and multifactorial process, and the genes whose altered expression appears to be a more important potential aetiological factor for asymmetry include PITX2, ACTN3, ENPP1 and ESR1. This systematic review attempts to systematise the available literature concerning the impact of signalling pathway disruption, including the disruption of the nodal signalling pathway, on the development of mandibular asymmetry.