The remnants of Hertwig's epithelial root sheath is known as:

When root dentin formation is completed, this portion of the basement membrane also disintegrates, as does the entire HERS. After this disintegration of the root sheath, its cells may become the epithelial rests of Malassez. These groups of epithelial cells become located in the mature periodontal ligament and can become cystic, presenting future problems.