[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.上皮根鞘在引导牙根发育过程中起着关键作用，其生长期间出现任何问题均可导致各种形式的牙根发育缺陷或异常。当上皮根鞘向牙乳头内过度增殖、卷叠时可发生牙根内陷。牙根内陷在组织来源和发生机制上与成釉器增殖、内卷所致牙冠内陷相似，但该类发育异常的名称、分类，以及牙内陷、牙根内陷和畸形根面沟三者间的关系尚无共识。本文以上皮根鞘在牙根发育过程中所起作用为切入点，探究牙根发育缺陷和异常的表现，重点梳理牙根内陷的发生、分类及其与牙内陷的关系，探讨牙根内陷的临床特点及对治疗的影响，以使临床医师对因上皮根鞘发育异常引发的牙齿疾病加深认识。.