Caries Pattern in Monozygotic Twin Based on Clinical, Medical and Behavioral Observations: A Case Study

Monozygotic twins are expected to be genetically identical, yet they seldom exhibit different phenotypes. Such rare occasions present a unique opportunity to untangle the role of epigenetic and environmental influence on the genetic expression of certain traits or diseases. Dental caries is a dynamic sugar- driven and biofilm-mediated disease of dental hard tissues that can result in demineralization and eventual structure loss if uninterrupted. The disease involves a complex interplay between environmental and genetic factors. The relative contribution of potential etiological factors can be unraveled by studying monozygotic twins. This case study involved a pair of 6-year-old monozygotic female twin who were referred for dental treatment. Thorough relevant medical and dental histories were obtained followed by a comprehensive clinical and radiographic assessment for both patients. In addition, insights into their oral hygiene practices and dietary habits were gained. Differences in their dentition and oral-health status were recorded. By presenting these differences, this report sought to highlight the impact of environmental factors on modifying the phenotypic expression in genetically identical individuals.