Epithelial cell rests of Malassez



In dentistry, the epithelial cell rests of Malassez or epithelial rests of Malassez (frequently abbreviated as ERM) 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 didn't completely disappear. It is considered that these cell rests proliferate to form epithelial lining of various odontogenic cysts such as radicular cyst under the influence of various stimuli. They are named after Louis-Charles Malassez (1842–1909) who described them.