Molar Incisor Hypomineralisation as a Dental Caries Risk Factor - Is It True?

The development of the human dentition is susceptible to disruption owing to its intricate and delicate nature, encompassing variations in tooth number, anatomical configuration, and the characteristics of enamel, dentine, and cementum. This chapter will specifically address the prevalent defect of molar incisor hypomineralisation (MIH), which can impose a significant treatment burden on individuals. MIH is linked to deleterious alterations in the properties of affected enamel, which can lead to rapid enamel breakdown and carious lesion formation in those at a heightened caries risk. In addition, MIH is associated with tooth sensitivity, dental anxiety, difficulty eating, aesthetic concerns, and negative influence during the child's psychological growth, especially when the MIH is severe. Regarding dental caries, it is essential to note that MIH does not directly increase the risk of caries. However, MIH can alter the way the caries process manifests by creating niches where biofilm can accumulate, complicating oral cleaning efforts. Additionally, MIH adversely modifies the physicochemical properties of enamel, influencing how this "hardest of tissues" responds to cariogenic challenges.