View source for Epithelial cell rests of Malassez

<p><a href="https://en.wikipedia.org/wiki/File:HERS.png"><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/HERS.png/220px-HERS.png" style="height:324px; width:220px" /></a></p>

<p>(1) The HERS, (2) epithelial rests of Malassez, (3) dental follicle, (4) cementoblasts, (5) periodontal ligament, (6) alveolar cells, (7) bone, (8) odontoblasts</p>

<p>In dentistry, the&nbsp;<strong>epithelial cell rests of Malassez</strong>&nbsp;(<strong>ERM</strong>) or&nbsp;<strong>epithelial rests of Malassez</strong>&nbsp;(<em>pax epithelialis pediodontii</em>) are part of the&nbsp;<a href="https://en.wikipedia.org/wiki/Periodontal_ligament" title="Periodontal ligament">periodontal ligament</a>&nbsp;cells around a&nbsp;<a href="https://en.wikipedia.org/wiki/Tooth#Periodontal_ligaments" title="Tooth">tooth</a>. They are discrete clusters of residual cells from&nbsp;<a href="https://en.wikipedia.org/wiki/Hertwig%27s_epithelial_root_sheath" title="Hertwig's epithelial root sheath">Hertwig&#39;s epithelial root sheath</a>&nbsp;(HERS) that didn&#39;t completely disappear. It is considered that these cell rests proliferate to form epithelial lining of various&nbsp;<a href="https://en.wikipedia.org/wiki/Odontogenic_cyst" title="Odontogenic cyst">odontogenic cysts</a>&nbsp;such as&nbsp;<a href="https://en.wikipedia.org/wiki/Radicular_cyst" title="Radicular cyst">radicular cyst</a>&nbsp;under the influence of various stimuli. They are named after&nbsp;<a href="https://en.wikipedia.org/wiki/Louis-Charles_Malassez" title="Louis-Charles Malassez">Louis-Charles Malassez</a>&nbsp;(1842&ndash;1909) who described them. Some rests become calcified in the periodontal ligament (<a href="https://en.wikipedia.org/wiki/Cementicle" title="Cementicle">cementicles</a>).</p>

<p>ERM plays a role in cementum repair and regeneration.<sup><a href="https://en.wikipedia.org/wiki/Epithelial_cell_rests_of_Malassez#cite_note-pmid16827716-1">[1]</a></sup>&nbsp;The stem cells in ERM can undergo an&nbsp;<a href="https://en.wikipedia.org/wiki/Epithelial" title="Epithelial">epithelial</a>&ndash;<a href="https://en.wikipedia.org/wiki/Mesenchymal" title="Mesenchymal">mesenchymal</a>transition and differentiate into diverse types of cells of&nbsp;<a href="https://en.wikipedia.org/wiki/Mesodermal" title="Mesodermal">mesodermal</a>&nbsp;and&nbsp;<a href="https://en.wikipedia.org/wiki/Ectodermal" title="Ectodermal">ectodermal</a>&nbsp;origin like bone, fat, cartilage and neuron-like cells.<sup><a href="https://en.wikipedia.org/wiki/Epithelial_cell_rests_of_Malassez#cite_note-pmid23931062-2">[2]</a></sup></p>