| Rf | in paper or thin-layer chromatography, the distance that a spot of a substance has moved from the po... |
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| RFLS | rheumatoid-factor-like substance |
| RPS | renal pressor substance; revolutions per second |
| RQ | recovery quotient; [Hazardous Substance] Reportable Quantities [List]; reportable quantity; respirat... |
| RS | radioscaphoid; random sample; rating schedule; Raynaud syndrome; recipient's serum; rectal sinus; re... |
| temporary tooth | A tooth of the first set of teeth, comprising 20 in all, that erupts between the mean ages of 6 and 28 months of life. Synonym: dens deciduus, baby tooth, deciduous dentition, dens lacteus, first dentition, milk tooth, primary dentition, primary tooth, temporary tooth. (05 Mar 2000) |
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| tip of tooth root | The tip of a tooth root, the part farthest from the incisal or occlusal side. Synonym: apex radicis dentis, root apex, root tip. (05 Mar 2000) |
| tooth | Pl> Teeth . [OE. Toth,tooth, AS. T; akin to OFries. Tth, OS. & D. Tand, OHG. Zang, zan, G. Zahn, Icel. Tnn, Sw. & Dan. Tand, Goth. Tumpus, Lith. Dantis, W. Dant, L. Dens, dentis, Gr, Skr. Danta; probably originally the p. Pr. Of the verb to eat. 239. Cf. Eat, Dandelion, Dent the tooth of a wheel, Dental, Dentist, Indent, Tine of a fork, Tusk. 1. <anatomy> One of the hard, bony appendages which are borne on the jaws, or on other bones in the walls of the mouth or pharynx of most vertebrates, and which usually aid in the prehension and mastication of food. The hard parts of teeth are principally made up of dentine, or ivory, and a very hard substance called enamel. These are variously combined in different animals. Each tooth consist of three parts, a crown, or body, projecting above the gum, one or more fangs imbedded in the jaw, and the neck, or intermediate part. In some animals one or more of the teeth are modified into tusks which project from the mouth, as in both sexes of the elephant and of the walrus, and in the male narwhal. In adult man there are thirty-two teeth, composed largely of dentine, but the crowns are covered with enamel, and the fangs with a layer of bone called cementum. Of the eight teeth on each half of each jaw, the two in front are incisors, then come one canine, cuspid, or dog tooth, two bicuspids, or false molars, and three molars, or grinding teeth. The milk, or temporary, teeth are only twenty in number, there being two incisors, one canine, and two molars on each half of each jaw. The last molars, or wisdom teeth, usually appear long after the others, and occasionally do not appear above the jaw at all. "How sharper than a serpent's tooth it is To have a thankless child !" (Shak) 2. Taste; palate. "These are not dishes for thy dainty tooth." (Dryden) 3. Any projection corresponding to the tooth of an animal, in shape, position, or office; as, the teeth, or cogs, of a cogwheel; a tooth, prong, or tine, of a fork; a tooth, or the teeth, of a rake, a saw, a file, a card. 4. A projecting member resembling a tenon, but fitting into a mortise that is only sunk, not pierced through. One of several steps, or offsets, in a tusk. See Tusk. 5., one of the appendages at the mouth of the capsule of a moss. See Peristome. 6. <zoology> Any hard calcareous or chitinous organ found in the mouth of various invertebrates and used in feeding or procuring food; as, the teeth of a mollusk or a starfish. In spite of the teeth, in defiance of opposition; in opposition to every effort. In the teeth, directly; in direct opposition; in front. "Nor strive with all the tempest in my teeth." . To cast in the teeth, to report reproachfully; to taunt or insult one with. Tooth and nail, as if by biting and scratching; with one's utmost power; by all possible means. "I shall fight tooth and nail for international copyright." . <medicine> Tooth coralline See Red-gum. To show the teeth, to threaten. "When the Law shows her teeth, but dares not bite." . To the teeth, in open opposition; directly to one's face. "That I shall live, and tell him to his teeth ." . Source: Websters Dictionary (01 Mar 1998) |
| tooth abnormalities | Congenital absence of or defects in structures of the teeth. (12 Dec 1998) |
| tooth abrasion | The pathologic wearing away of the tooth substance by brushing, bruxism, clenching, and other mechanical causes. It is differentiated from tooth attrition in that this type of wearing away is the result of tooth-to-tooth contact, as in mastication, occurring only on the occlusal, incisal, and proximal surfaces. It differs also from tooth erosion, the progressive loss of the hard substance of a tooth by chemical processes not involving bacterial action. (12 Dec 1998) |
| tooth abscess | A localised pus-forming bacteria infection adjacent to the tooth or root. Large tooth abscesses may require surgical drainage, root canal or a tooth extraction. See: apical abscess. (27 Sep 1997) |
| tooth-and-nail syndrome | <syndrome> Hypodontia associated with absent or very small nails at birth. Common among Dutch Mennonites in Canada. (05 Mar 2000) |
| tooth apex | The tip or terminal end of the root of a tooth. (12 Dec 1998) |
| tooth arrangement | The placement of teeth on a denture base with definite objectives in mind. The setting of teeth on temporary bases. (05 Mar 2000) |
| tooth, artificial | A fabricated tooth substituting for a natural tooth in a prosthesis. It is usually made of porcelain or plastic. (12 Dec 1998) |
| tooth attrition | The wearing away of a tooth as a result of tooth-to-tooth contact, as in mastication, occurring only on the occlusal, incisal, and proximal surfaces. It is chiefly associated with aging. It is differentiated from tooth abrasion (the pathologic wearing away of the tooth substance by friction, as brushing, bruxism, clenching, and other mechanical causes) and from tooth erosion (the loss of substance caused by chemical action without bacterial action). (12 Dec 1998) |
| tooth avulsion | Partial or complete displacement of a tooth from its alveolar support. It is commonly the result of trauma. (12 Dec 1998) |
| tooth bleaching | The use of a chemical oxidizing agent (sometimes in combination with heat) to lighten tooth discolorations. (boucher's clinical dental terminology, 4th ed, p34) (12 Dec 1998) |
| tooth-borne | A term used to describe a prosthesis or part of a prosthesis which depends entirely upon the abutment teeth for support. (05 Mar 2000) |
| tooth-borne base | The denture base restoring an edentulous area which has abutment teeth at each end for support; the tissue which it covers is not used for support. (05 Mar 2000) |