Epithelial cell rests of Malassez
In dentistry, the epithelial cell rests of Malassez (ERM) or epithelial rests of Malassez (pax epithelialis pediodontii) are part of the periodontal ligament cells around a tooth. They are discrete clusters of residual cells from Hertwig's epithelial root sheath (HERS) that did not completely disappear.
Source: Wikipedia — Epithelial cell rests of Malassez (CC BY-SA 4.0)