HERS is formed by:
Formation of the root sheath begins with the formation of the Hertwig's root sheath. Hertwig's root sheath is the apical extension of the cervical loop of enamel epithelium. At the cervical loop, the stratum intermedium is lost and the outer and the inner enamel epithelium come in contact.
Cells of stratum intermedium.
Cells of IEE.
Cells of the cervical loop.
Cells of the apical periodontium.