| oral ulcer | A loss of mucous substance of the mouth showing local excavation of the surface, resulting from the sloughing of inflammatory necrotic tissue. It is the result of a variety of causes, e.g., denture irritation, aphthous stomatitis (stomatitis, aphthous), noma, necrotizing gingivitis (gingivitis, necrotizing, ulcerative), toothbrushing, and various irritants. (12 Dec 1998) |
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| oral vestibule | That part of the mouth bounded anteriorly and laterally by the lips and the cheeks, posteriorly and medially by the teeth and/or gums, and above and below by the reflections of the mucosa from the lips and cheeks to the gums. Synonym: vestibulum oris, buccal cavity, vestibule of mouth. (05 Mar 2000) |
| tuberculosis, oral | Tuberculosis of the mouth, tongue, and salivary glands. (12 Dec 1998) |
| florid oral papillomatosis | Diffuse involvement of the lips and oral mucosa with benign squamous papillomas; microscopically, it resembles verrucous carcinoma, but is not invasive or localised to a specific area of the oral mucosa. (05 Mar 2000) |
| leukoedema, oral | A disorder of the buccal mucosa resembling early leukoplakia, characterised by the presence of filmy opalescence of the mucosa in the early stages to a whitish gray cast with a coarsely wrinkled surface in the later stages, associated with intracellular oedema of the spinous or malpighian layer. (12 Dec 1998) |
| leukoplakia, oral | A white patch seen on the oral mucosa. It is considered a premalignant condition and is often tobacco-induced. When evidence of epstein-barr virus is present, the condition is called hairy leukoplakia (leukoplakia, hairy). (12 Dec 1998) |
| lichen planus, oral | Oral lesions accompanying cutaneous lichen planus or often occurring alone. The buccal mucosa, lips, gingivae, floor of the mouth, and palate are usually affected (in a descending order of frequency). Typically, oral lesions consist of radiating white or gray, velvety, threadlike lines, arranged in a reticular pattern, at the intersection of which there may be minute, white, elevated dots or streaks (wickham's striae). (12 Dec 1998) |
| live oral poliovirus vaccine | Inactivated poliovirus vaccine (IPV), an aqueous suspension of inactivated strains of poliomyelitis virus (types 1, 2, and 3) used by injection; has largely been replaced by the oral vaccine. See: Salk vaccine. (05 Mar 2000) |
| activated clotting time | The most common test used for coagulation time in cardiovascular surgery. (05 Mar 2000) |
| activated partial thromboplastin time | The time needed for plasma to form a fibrin clot following the addition of calcium and a phospholipid reagent; used to evaluate the intrinsic clotting system. (05 Mar 2000) |
| A-H conduction time | Forward conduction of the cardiac impulse from atria to ventricles via the A-V node or any bypass tract, represented in the electrocardiogram by the P-R interval. P-H conduction time is from the onset of the P wave to the first high frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high frequency component of the atrial electrogram to the first high frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). (05 Mar 2000) |
| association time | Time elasping between a stimulus and the verbalised response to it. (05 Mar 2000) |
| biologic time | The concept that our appreciation of time varies with age and is governed by the neural organization of the individual; it obeys a logarithmic rather than an arithmetic law. (05 Mar 2000) |
| bleeding time | <haematology> A test which measures the time it takes for small blood vessels to close off and bleeding to stop. Abnormal results can be seen in those with congenital or acquired platelet function disorders or thrombocytopenia. (27 Sep 1997) |
| blood circulation time | Determination of the shortest time interval between the injection of a substance in the vein and its arrival at some distant site in sufficient concentration to produce a recognizable end result. It represents approximately the inverse of the average velocity of blood flow between two points. (12 Dec 1998) |