résorption

Résorption is a biological process in which tissue or mineral is degraded and absorbed by the body. It is a normal aspect of tissue turnover and mineral homeostasis, contributing to development, remodeling, and healing. In clinical contexts, résorption can refer to physiologic remodeling or to pathological loss of tissue caused by cellular resorption.

In bone, resorption is mainly carried out by osteoclasts, which dissolve mineralized matrix and release calcium and phosphate into the bloodstream. It is tightly coordinated with bone formation by osteoblasts, maintaining skeletal integrity. Regulatory pathways include RANKL, RANK, and osteoprotegerin (OPG), and hormonal signals such as parathyroid hormone and estrogen. Excessive resorption or insufficient formation underlie conditions like osteoporosis and osteolytic lesions; diminished remodeling may contribute to sclerosis or fracture risk.

In dentistry, résorption denotes loss of dental hard tissue due to clastic activity. External resorption affects the surface of a tooth and its root, while internal resorption starts within the pulp chamber. Causes include trauma, inflammation, orthodontic forces, infection, and pressure from tumors. Diagnosis is typically radiographic; treatment depends on cause and stage, ranging from monitoring to endodontic or surgical intervention, and sometimes extraction.

Outside skeletal and dental contexts, résorption can describe reabsorptive processes in other tissues or organ systems associated with healing or disease. It is distinct from formation, the process of building new tissue, and the two processes are usually tightly linked in physiological remodeling.

See also: bone remodeling, osteoclasts, odontoclasts, root resorption.