Mirror-image phenomenon in Turkish monozygotic twins: A report of 3 cases.

Due to the special circumstances and the pre-natal environment in twin gestations, disruptions in the development of the embryo are more frequently observed in twin births as compared to singleton births. Twin research provides an excellent model to explore the etiology of disruptions in craniofacial biology. Mirror imaging (MI) is a special manifestation of twinning, and the elucidation of the etiology of this phenomenon is important to understand the biological mechanisms which underlie congenital defects, like orofacial clefts, and to provide insight into left-right asymmetry. The aim of this paper was, therefore, to present 3 pairs of Turkish monozygotic (MZ) twins with MI dental features, and to contribute to the knowledge of the MI phenomenon in the literature. We examined 2 male and 1 female MZ twin pairs clinically and radiographically in terms of their MI features. Mirrorimage features in dental and other ectodermal structures were detected in all the twins. Understanding the biological mechanisms of MI provides broad insight into preventive measures and treatment protocols. Furthermore, the presence of MI features may lead to the detection of other MI pathologies in twins.