Molar Incisor Hypomineralisation (MIH) is a prevalent enamel defect affecting both permanent and deciduous teeth, posing significant clinical challenges. This literature review aims to comprehensively evaluate the etiology, prevalence, clinical manifestations, diagnostic methods, and management strategies of MIH in permanent and deciduous dentitions, while identifying current knowledge gaps and suggesting directions for future research. The prevalence of MIH varies globally, ranging from 3% to 40%, with the highest rates observed in South America (7-40%) and Africa (10-30%), compared to Europe (8-25%) and Asia (3-20%). Gender distribution is nearly equal, though some regions report a slight female predominance. Genetic factors, prenatal and perinatal complications, childhood illnesses, and environmental exposures such as dioxins significantly contribute to MIH etiology. Clinically, MIH presents as demarcated opacities, post-eruptive enamel breakdown, and increased caries susceptibility, affecting approximately 70% of affected first permanent molars and 60% of incisors. Management strategies vary based on severity, with mild cases managed through preventive measures like fluoride varnish, while severe cases often require restorative interventions such as resin composites and stainless steel crowns. The economic burden is substantial, with affected individuals necessitating frequent and costly dental treatments, and MIH adversely impacts quality of life by increasing dental anxiety and affecting aesthetics. MIH is a widespread and multifactorial dental condition with significant clinical and socioeconomic implications. Effective management necessitates a multidisciplinary approach, and further research is essential to elucidate its etiology and develop robust preventive and therapeutic strategies.