epithelial cell rests of Malassez
Tuesday 24 May 2011
Definition: The epithelial cell rests of Malasse are discrete clusters of residual cells from Hertwig’s epithelial root sheath (HERS) that didn’t completely disappear.
The epithelial cell rests of Malassez are part of the periodontal ligament cells around a tooth.
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. Some rests become calcified in the periodontal ligament (cementicles)
The epithelial cell rests of Malassez (ERM) are formed by persisting fragments of epithelial sheath (Hertwig shaeth) that participates in the tooth root development.
ERM are found within the periodontal ligament. They undergo intensive age-related involution and are traditionally described as small clusters of functionally inactive cells.
Meanwhile, recent findings are indicative of high functional activity of ERM which are both producers of and targets for various cytokines, growth factors, adhesive substances, their receptors and other biologically active molecules.
It is suggested that ERM participate in sustaining the optimal conditions for the normal functioning and regeneration of periodontium structural components.
When periodontal tissue homeostasis is disturbed, ERM may grow up and acquire the capacity to destroy the surrounding tissues.