Cementoclast

Cementoclast is a multinucleated cell that resorbs dental cementum, the mineralized tissue covering tooth roots. It is considered an osteoclast-like cell derived from the monocyte/macrophage lineage and shares many morphological and functional features with osteoclasts.

Resorption occurs at resorption lacunae on cementum surfaces and is mediated by acid secretion and lysosomal proteases at a ruffled border, driven by RANKL signaling and M-CSF as with osteoclastogenesis.

Cementoclasts participate in physiologic root resorption seen during shedding of deciduous teeth; they are also implicated in pathologic resorption processes involving cementum, including external cervical resorption, inflammatory resorption after trauma, and orthodontic-induced resorption when tooth movement causes exposure of cementum to resorptive cells.

Histologically, cementoclasts are large multinucleated cells located on cementum surfaces in resorption bays. They are closely related to odontoclasts and osteoclasts; however, cementoclasts preferentially resorb cementum, whereas odontoclasts resorb dentin. Distinguishing the cell type often depends on the tissue being resorbed and anatomical location rather than based on distinct markers.

Clinical relevance: their activity can threaten tooth support; management aims to identify and control resorptive stimuli, remove resorbing tissue, and treat underlying causes.