Tooth morphology is shaped by a complex interplay of genetic, environmental, systemic, and local factors acting during development and throughout post-eruptive life. This narrative review synthesizes current evidence on factors influencing tooth development and post-developmental changes, with emphasis on clinical and morphological implications. During odontogenesis, disturbances in morphodifferentiation, matrix formation, and mineralization may result in anomalies of size, shape, and structure. Traumatic injuries to primary teeth, particularly at younger ages, can disrupt the developing permanent successors, producing defects ranging from enamel hypoplasia and opacities to crown malformations. Local infections, surgical interventions, and perinatal trauma further contribute to developmental disturbances, often in a site-specific pattern depending on the timing and severity of insult. Following eruption, teeth are subjected to continuous functional and environmental challenges. Post-developmental changes such as attrition, abrasion, and erosion lead to irreversible loss of hard tissue and progressive modification of crown morphology. These processes are frequently multifactorial and may be compounded by restorative procedures or cultural practices involving intentional crown alteration. Together, developmental disturbances and post-eruptive modifications significantly influence dental form and structural integrity across the lifespan. Understanding the mechanisms, timing, and clinical presentation of these changes is essential for accurate diagnosis, treatment planning, and forensic interpretation. This review highlights the dynamic nature of dental morphology and underscores the importance of integrating developmental history with clinical findings in comprehensive dental assessment.