[Clinical challenges caused by defective Hertwig's epithelial root sheath proliferation Ⅰ: pathogenesis and treatment of taurodontism].

Hertwig's epithelial root sheath precisely regulates the morphology and structure of tooth roots. During root development, interference in the spatiotemporal development of the Hertwig's epithelial root sheath can lead to excessive or defective proliferation, subsequently causing morphological variations of root and pulp cavity. Taurodontism is a characteristic manifestation resulting from defective Hertwig's epithelial root sheath proliferation, presenting with abnormal root and pulp morphology. Currently, clinicians have an incomplete understanding and conceptual confusion regarding its pathogenesis, anatomical features, and clinical manifestations, which hinders accurate root canal therapy difficulty assessment and optimal treatment planning. This article, taking the role of the epithelial root sheath in root development as its starting point, systematically reviews the mechanisms of taurodontism formation, nomenclature, classification, and research progress. It further analyzes its clinical characteristics, and proposes strategies for root canal therapy. The aim is to enhance clinicians' comprehensive understandings of this root developmental anomaly, thereby improving the success rates of clinical treatments.