Abstract
Tooth agenesis is among the most prevalent congenital anomalies affecting human dentition, characterized by the developmental absence of one or more teeth. This condition may be present in either syndromic or non-syndromic forms, with significant implications for oral function, aesthetics, and craniofacial development. This narrative review aims to provide a comprehensive overview of tooth agenesis, defining its classification, genetic underpinnings, epidemiological aspects, phenotypic features, and therapeutic approaches. Recent advances in genetic research have identified numerous causative genes, notably EDA, MSX1, WNT10A, and PAX9, each associated with specific patterns of missing teeth and involved in isolated and/or syndromic forms. Additionally, genes such as TSPEAR, LRP6, PITX2, and GREM2 contribute to varying degrees of severity and tooth distribution, often blurring the lines between syndromic and isolated cases. The genotype-phenotype correlations underscore the complexity of the underlying molecular pathways involved in odontogenesis. From a therapeutic perspective, the management of tooth agenesis requires a multidisciplinary approach, often involving orthodontic, prosthetic, and surgical interventions tailored to the severity of tooth loss and patient age. Early diagnosis represents a crucial role in treatment planning, facilitating timely intervention during growth and enhancing long-term outcomes. In conclusion, tooth agenesis remains a complex clinical condition with a strong genetic basis. A patient-centered and interdisciplinary strategy is essential to address both functional and psychosocial needs.