Epithelial Cell Rests of Malassez

Epithelial cell rests of Malassez are microscopic clusters or strands of epithelial cells that remain in the periodontal ligament following the completion of tooth root formation. They represent fragments of the embryonic root sheath (Hertwig’s sheath).

Etiology and pathophysiology

Normally, these cells remain in a dormant state without any activity. However, in the development of chronic inflammation at the root apex (apical periodontitis), bacterial metabolic products can stimulate these cells to divide. Active proliferation of epithelial remnants is a key mechanism in forming the lining of a radicular (root) cyst.

Clinical significance

Understanding the role of the epithelial cell rests of Malassez is critically important for the diagnosis of cysts.

Epithelial cells in the rests of Malassez can secrete factors that resorb bone tissue. To date, there is no direct evidence of whether regression of the epithelial lining of a cyst can occur after nonsurgical endodontic treatment. Considering possible pathogenetic mechanisms, epithelial growth may cease upon the removal of the stimulating bacterial factor, such as after endodontic treatment. Subsequently, the epithelial lining may thin or disappear, creating conditions for healing. Subsequently, if healing of the periapical lesion does not occur, cyst enucleation (cystectomy) is performed.