| vertical retraction syndrome | <syndrome> A retraction of the globe and pseudoptosis on attempted adduction; due to co-innervation of the horizontal recti. Sometimes there is an inability to abduct the affected eye (type 1), or adduct the affected eye (type 2), or both (type 3). Synonym: Duane's syndrome. (05 Mar 2000) |
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| retraction syndrome | <syndrome> A retraction of the globe and pseudoptosis on attempted adduction; due to co-innervation of the horizontal recti. Sometimes there is an inability to abduct the affected eye (type 1), or adduct the affected eye (type 2), or both (type 3). Synonym: Duane's syndrome. (05 Mar 2000) |
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| gingival retraction | Lateral movement of the gingival margin away from the tooth surface; may be indicative of underlying inflammation or pocket formation, displacement of the marginal gingivae away from the tooth by mechanical, chemical, or surgical means. Mandibular retraction, a type of facial anomaly in which the gnathion lies posterior to the orbital plane. (05 Mar 2000) |
| pathologic retraction ring | A constriction located at the junction of the thinned lower uterine segment with the thick retracted upper uterine segment, resulting from obstructed labour; this is one of the classic signs of threatened rupture of the uterus. Synonym: Bandl's ring, Baudelocque's uterine circle, Scanzoni's second os. (05 Mar 2000) |
| retraction | 1. The act of drawing back, the condition of being drawn back. 2. Distal movement of teeth, usually accomplished with an orthodontic appliance. Origin: L. Retrahere = to draw back (18 Nov 1997) |
| retraction fibre | Thin projections from crawling cells associated with areas where the cell body is becoming detached from the substratum, but focal adhesions persist. Usually contain a bundle of microfilaments that are under tension. (18 Nov 1997) |
| retraction of publication | A statement issued by one or more authors of an article or a book, withdrawing or disavowing acknowledgment of their participation in performing research or writing the results of their study. In indexing, the retraction is sent to the editor of the publication in which the article appeared and is published under the rubric "retraction" or in the form of a letter. This publication type designates the author's statement of retraction: it should be differentiated from retracted publication which labels the retracted publication. (12 Dec 1998) |
| clot retraction | Retraction of a clot resulting from contraction of platelet pseudopods attached to fibrin strands that is dependent on the contractile protein thrombosthenin. Used as a measure of platelet function. (12 Dec 1998) |
| clot retraction time | The time required for a blood clot to separate from the tube wall and express serum, usually completed in 18 to 24 hours, but retarded or absent in persons with thrombocytopenic purpura. (05 Mar 2000) |
| physiologic retraction ring | A ridge on the inner uterine surface at the boundary line between the upper and lower uterine segment that occurs in the course of normal labour. (05 Mar 2000) |
| convergence-retraction nystagmus | Irregular, jerky nystagmus combining convergence and retraction of the eye into the orbit, especially on attempting an upward gaze. Synonym: Koerber-Salus-Elschnig syndrome. (05 Mar 2000) |
| vertical | 1. Of or pertaining to the vertex; situated at the vertex, or highest point; directly overhead, or in the zenith; perpendicularly above one. "Charity . . . Is the vertical top of all religion." (Jer. Taylor) 2. Perpendicular to the plane of the horizon; upright; plumb; as, a vertical line. <astronomy> Vertical angle, an angle measured on a vertical circle, called an angle of elevation, or altitude, when reckoned from the horizon upward, and of depression when downward below the horizon. <botany> Vertical anthers The plane passing through the point of sight, and perpendicular to the ground plane, and also to the picture. Vertical sash, a sash sliding up and down. Cf. French sash, under 3d Sash. Vertical steam engine, a steam engine having the crank shaft vertically above or below a vertical cylinder. Origin: Cf. F. Vertical. See Vertex. 1. Vertical position; zenith. 2. <mathematics> A vertical line, plane, or circle. Prime vertical, Prime vertical dial. See Prime. Source: Websters Dictionary (01 Mar 1998) |
| vertical axis | In dentistry, the line around which the working side condyle rotates in the horizontal plane during mandibular movement. (05 Mar 2000) |
| vertical classification | <zoology> Classification which stresses common descent and tends to unite ancestral and descendant groups of a phyletic line in a single higher taxon, separating them from contemporaneous taxa having reached a similar grade of evolutionary change. Compare: Horizontal classification. (09 Jan 1998) |
| vertical dimension | The length of the face determined by the distance of separation of jaws. Occlusal vertical dimension (ovd or vdo) or contact vertical dimension is the lower face height with the teeth in centric occlusion. Rest vertical dimension (vdr) is the lower face height measured from a chin point to a point just below the nose, with the mandible in rest position. (12 Dec 1998) |
| vertical displacement event | Disruption which occurs because plasma is not adequately stabilised against vertical motions. (09 Oct 1997) |