Management of immature permanent teeth with incomplete root development presents a significant challenge in endodontics. Preservation of pulp vitality and promotion of continued root maturation are critical for ensuring long-term tooth survival and functionality. Apexogenesis and apexification are two well-established treatment modalities used to manage immature teeth with open apices. Apexogenesis aims to maintain vital pulp tissue, allowing continued root development and apical closure, whereas apexification induces the formation of a calcified apical barrier in non-vital teeth. Advances in biomaterials such as Mineral Trioxide Aggregate (MTA), Biodentine, and regenerative endodontic procedures have significantly improved clinical outcomes. This review comprehensively examines the biological principles, indications, techniques, materials, clinical outcomes, advantages, limitations, and future directions of apexification and apexogenesis. Current evidence supports vital pulp therapy and regenerative approaches whenever possible, while MTA-based apexification remains a predictable treatment for necrotic immature teeth. Continued advancements in regenerative endodontics are expected to transform treatment strategies and improve long-term prognosis.