retraction

1. A shrinking, drawing back, or pulling apart. 2. Posterior movement of teeth, usually with the aid of an orthodontic appliance. [L. retractio, a drawing back]

- gingival r. 1. lateral movement of the gingival margin away from the tooth surface; may be indicative of underlying inflammation or pocket formation; 2. displacement of the marginal gingivae away from the tooth by mechanical, chemical, or surgical means.

- mandibular r. a type of facial anomaly in which the gnathion lies posterior to the orbital plane.

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re·trac·tion ri-'trak-shən n an act or instance of retracting specif backward or inward movement of an organ or part <\retraction of the nipple or skin overlying the tumor (Jour. Amer. Med. Assoc.)>

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n.

1. (in obstetrics) the quality of uterine muscle fibres of remaining shortened after contracting during labour. This results in a gradual progression of the fetus downwards through the pelvis. The basal portion of the uterus becomes thicker and pulls up the dilating cervix over the presenting part.

2. (in dentistry) the drawing back of one or more teeth into a better position by an orthodontic appliance.

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re·trac·tion (re-trakґshən) [L. retrahere to draw back] 1. the act of drawing back; the condition of being drawn back. 2. distal movement of teeth, usually accomplished with an orthodontic appliance.