avascular necrosis

avascular necrosis.

See coagulation necrosis.

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necrosis (nekrō´sis),

n 1. the death of a cell or group of cells in contact with living tissue.
n 2. the local death of cells resulting from, e.g., loss of blood supply, bacterial toxins, or physical or chemical agents.

necrosis, avascular

n the consequence of temporary or permanent cessation of blood flow to the bones. The absence of blood causes the bone tissue to die, resulting in fracture or collapse of the entire bone.

necrosis, caseous

n a change commonly associated with tuberculosis and characterized by dry, soft, and cheesy tissue.

necrosis, exanthematous

n an acute necrotizing process involving the gingivae, jawbones, and contiguous soft tissues. It is of unknown cause, primarily affects children, and resembles noma. It differs from noma, however, in that it has a slight odor, tendency for self-limitation, low mortality rate, and normal leukocyte count. See also noma.

necrosis, gingival,

n death and degeneration of the cells and other structural elements of the gingivae (e.g., necrotizing ulcerative gingivitis).

necrosis, interdental,

n a progressive disease that destroys the tissue of the papillae and creates interdental craters. Advanced interdental necrosis leads to a loss of periodontal attachment.

necrosis, ischemic,

n death and disintegration of a tissue resulting from interference with its blood supply, thus depriving the tissues of access to substances necessary for metabolic sustenance. It may occur in the periodontal ligament as a result of occlusal trauma.

necrosis of epithelial attachment,

n the death of cells composing the epithelial attachment. In a specific periodontitis produced by organisms similar to
Actinomyces, necrosis of the epithelial attachment may exist, permitting a rapid apical shift of the base of the pocket.

necrosis, periodontal ligament,

n necrosis of a portion of the periodontal ligament, usually resulting from traumatic injury (e.g., in occlusal traumatism). Much of this necrotic change is the result of ischemia.

necrosis, radiation,

n the death of tissue caused by radiation.