Epithelial Root Sheath

Epithelial Root Sheath

The Hertwig's epithelial root sheath (frequently abbreviated as "HERS") is a proliferation of epithelial cells located at the cervical loop of the enamel organ in a developing tooth. Hertwig's epithelial root sheath initiates the formation of dentin in the root of a tooth by causing the differentiation of odontoblasts from the dental papilla. The root sheath eventually disintegrates, but residual pieces that do not completely disappear are seen as epithelial cell rests of Malassez (ERM).