abrasion /əbrā″zhən/ [L, abradere, to scrape off] , a scraping or rubbing away of a surface, such as skin or teeth, by a substance or surface with a hardness greater than that of the tissue being scraped or rubbed away. Abrasion may be the result of trauma, such as a skinned knee; of therapy, as in dermabrasion for the removal of scar tissue; or of normal function, such as the wearing down of a tooth by mastication. Compare laceration. See also bruxism, friction burn. −abrasive, adj., −abrade, v.
