Odontoclasts

Odontoclasts are multinucleated cells of the monocyte–macrophage lineage that resorb dental hard tissues, particularly dentin and cementum; enamel resorption is rare due to enamel’s acellularity. They attach to mineralized surfaces and form resorption bays known as Howship’s lacunae, secreting acids and proteolytic enzymes to dissolve mineral and organic matrix.

Odontoclasts are involved in both physiologic and pathologic resorption. They arise from the same macrophage lineage as osteoclasts and function at sites of dentin or cementum resorption. In normal development, odontoclasts mediate root resorption during the shedding of deciduous teeth and during eruption of permanent teeth, allowing shedding and subsequent replacement.

Pathologic resorption can be external, affecting the root surface beneath the periodontal ligament after trauma, infection, or orthodontic tooth movement, or internal, originating from inflammatory processes within the pulp or root canal that lead to resorption from within the root canal wall. The extent and pattern of resorption influence prognosis and treatment decisions.

Diagnosis is based on clinical examination and radiographic imaging, with attention to timing, location, and potential etiologic factors. Management aims to eliminate the underlying cause, control inflammation, and monitor tooth integrity; extensive resorption may require intervention to preserve function or consider extraction. Odontoclast activity is a key consideration in endodontics, orthodontics, and pediatric dentistry regarding tooth development and retention.