Epithelial cell rests of Malassez

Epithelial cell rests of Malassez (ERM) are a group of residual cells that can be found in the periodontal ligament after tooth eruption. These cells are remnants of the Hertwig's epithelial root sheath (HERS) that didn't completely disappear and have the potential to proliferate and form cysts or tumors in certain conditions.

History[edit | edit source]

The ERM were first described by a French histologist, Louis-Charles Malassez, in 1885. He discovered these cell clusters while studying the periodontal ligament and named them "epithelial cell rests".

Structure[edit | edit source]

The ERM are clusters of epithelial cells that are located within the periodontal ligament. They are usually inactive, but under certain conditions, they can proliferate and form cysts or tumors. The size and number of these cell clusters can vary greatly among individuals.

Function[edit | edit source]

The primary function of the ERM is not fully understood. However, they are believed to play a role in the maintenance and repair of the periodontal ligament. Some studies suggest that they may also be involved in the formation of cementum, a hard tissue that covers the root of the tooth.

Clinical significance[edit | edit source]

The ERM are usually harmless. However, under certain conditions, they can proliferate and form cysts or tumors. This can occur as a result of inflammation, trauma, or other pathological conditions. The most common type of tumor that can arise from the ERM is the odontogenic keratocyst (OKC), which is a benign but locally aggressive tumor.