Developmental defects of teeth are caused by complex interactions between genetic and environmental factors that affect the structure of enamel during its formation. Developmental defects increase the risk for diseases that impact negatively on the quality of life. Enamel Hypomineralization is a qualitative defect of enamel associated with hypomineralized first permanent molars as well as incisors, caused by multiple factors. It is frequently present in children with amoxicillin history during the first four years of life. Affected molars are associated with demarcated opacities which vary in color from white to brown resembling discolored chalk or old Dutch cheese. Clinical difficulties associated with MIH include dental caries, failure of anesthesia and failure of restorations. Managing such patients require a variety of approaches, materials, and techniques. Early diagnosis allows monitoring of First Permanent Molars so that remineralization and preventive measures such as fluoride toothpaste, fluoride varnishes or CPP-ACP pastes could be instituted as soon as affected surfaces are accessible.