[Radicular invaginatus caused by the developmental abnormalities of epithelial root sheath]

Epithelial root sheath plays a key role in guiding the development of tooth root. Any problems during its growth can lead to various forms of defects or abnormalities in the development of tooth root. Radicular invaginatus may occur when the epithelial root sheath excessively proliferates and infolds into the dental papilla. In terms of tissue origin and occurrence mechanism, the radicular dens invaginatus is similar to the coronal invaginatus which is led by the proliferation and infolding of enamel organ. However, there had been no consensus on the term and classification of this type of developmental abnormality as well as the relationships among the dens invaginatus, the radicular invaginatus and the palatogingival groove. From the role of epithelial root sheath during root development, the manifestations of root developmental defects and abnormalities will be analyzed. The pathogeny, classification, clinical characteristics of the radicular invaginatus, the relationship with the dens invaginatus and the impact on treatment were specially focused on.