- A systematic arrangement into classes or groups based on perceived common characteristics; a means of giving order to a group of disconnected facts.- adansonian c. the c. of organisms based on giving equal weight to every character of the organism; this principle has its greatest application in numerical taxonomy. [M. Adanson]- Angle c. of malocclusion a c. of different types of malocclusion, based on the mesiodistal relationship of the permanent molars upon their eruption and locking, and comprised of three classes; Class I: normal relationship of the jaws, wherein the mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first permanent molar; Class II: distal relationship of the mandible, wherein the distobuccal cusp of the maxillary first permanent molar occludes in the buccal groove of the mandibular first molar, and further classified as Division 1, labioversion of maxillary incisor teeth, and Division 2, linguoversion of maxillary central incisors, both of which may be unilateral conditions; Class III: mesial relationship of the mandible, wherein the mesiobuccal cusp of the maxillary first molar occludes in the embrasure between the mandibular first and second permanent molars, further classified as a unilateral condition.- Arneth c. a c. of the polymorphonuclear neutrophils according to the number of their nuclear lobes. See Arneth stages, under stage.- Bethesda c. SYN: Bethesda system.- Caldwell-Moloy c. a c. of the variations in the female pelvis; namely gynecoid, android, anthropoid, and platypelloid pelvis, based on the type of the posterior and anterior segments of the inlet.- Cummer c. a listing of several types of removable partial dentures in accordance with the distribution of direct retainers.- DeBakey c. consists of three types: Type I extends into the transverse arch and distal aorta and type II is confined to the ascending aorta; type III dissections begin in the descending aorta, with type IIIA extending toward the diaphragm and type IIIB extending below it.- Denver c. a system of nomenclature for human mitotic chromosomes, based on length and position of the centromere. [Denver, Colorado, where agreed upon]- Dukes c. a c. of the extent of invasion of a resected adenocarcinoma of the colon or rectum commonly modified as follows: A (Dukes A), confined to the mucosa; B1, into the muscularis mucosae; B2, through the muscularis mucosae; C1, limited to the bowel wall, with nodal metastases; C2, through the bowel wall, with nodal metastases.- FAB c. French-American-British c. of acute leukemias based on the study of microscopic features and cytochemistry of blast cells; it subdivides acute myelogenous leukemias into 8 groups (M0–M7) and acute lymphoblastic leukemias into 3 groups (L1–L3); widely used in clinical practice. SYN: French-American-British c..- French-American-British c. SYN: FAB c..- Gell and Coombs C. (gel koomz) a c. system that differentiates the 4 types of hypersensitivity reactions: Type I: anaphylactic reactions, Type II: cytotoxic reactions, Type III: immune complex reactions, and Type IV: cell-mediated/delayed hypersensitivity reactions.- International Labour Organization C. ILO 1980 International C. of Radiographs of the Pneumoconioses; a system for qualitative and semiquantitative description of the chest radiographic findings caused by pneumoconiosis, designed for epidemiologic studies; supersedes classifications of 1950, 1958, 1968, and 1971.- Kennedy c. a listing of several forms of partially edentulous jaws in accordance with the distribution of the missing teeth.- Kiel c. c. of non-Hodgkin lymphoma into low-grade malignancy (lymphocytic, lymphoplasmacytoid, centrocytic, and centroblastic-centrocytic types) and high-grade malignancy (centroblastic, lymphoblastic of Burkitt or convoluted cell, and immunoblastic types). SYN: Lennert c..- Lancefield c. a serologic c. dividing hemolytic streptococci into groups (A to O) which bear a definite relationship to their sources, based upon precipitation tests depending upon group-specific substances that are carbohydrate in nature; e.g., Group A contains strains most pathogenic for humans; B, strains from mastitis in cows and from normal milk, including strains from the human throat and vagina; C, strains from various lower animals, including a number from cattle and the human throat; D, strains from cheese and humans; E, strains from certified milk; F, strains mainly from the human throat, associated with tonsillitis; G, strains from humans, a few from monkeys and dogs; and H, K, and O, nonpathogenic strains occasionally from normal human respiratory tracts.- Lennert c. SYN: Kiel c..- Lukes-Collins c. a c. of lymphomas according to the immunologic nature of the cell of origin, based on histologic and clinical data.- multiaxial c. a procedure used in DSM-III-R for diagnosing patients on five axes : 1) psychiatric syndrome present; 2) patient's history of personality and developmental disorders; 3) possible nonmental medical disorders; 4) severity of psychosocial stressors; 5) highest level of adaptive functioning in the past year.- New York Heart Association c. a functional c. to assess cardiovascular disability. Class I: patients with cardiac disease without limitation of physical activity. Ordinary activity does not cause symptoms. Class II: patients with cardiac disease with slight limitation of activity; comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea or angina. Class III: patients with cardiac disease producing marked limitation of activity : comfortable at rest. Less than ordinary physical activity causes symptoms. Class IV: patients with cardiac disease resulting in inability to carry on any physical activity without discomfort. Symptoms may be present even at rest.- Rappaport c. a histologic c. of lymphomas in use before the availability of recent methods for identification of B- and T-type lymphocytes.- REAL c. a c. of lymphoma first published in 1994 and based on the correlation of clinical features of lymphomas with their histopathology and immunophenotype and genotype of neoplastic cells; groups lymphoproliferative diseases into chronic leukemia/lymphoma, nodal or extranodal lymphoma, acute leukemia lymphoma, plasma cell disorders, and Hodgkin disease. [Revised European-American llymphoma c.]- Runyon c. a c. scheme for mycobacteria other than Mycobacterium tuberculosis that divides species into four categories: 1) photochromogens, species that produce a yellow to brown carotene pigment when grown in the presence of light; 2) scotochromogens, which produce pigment in presence or absence of light; 3) nonpigmented, which do not produce pigment; and 4) rapid growers, which grow on solid media in 5–10 days rather than 4–8 weeks. This c. has no clinical or genetic significance but remains of limited value in identification of some clinical isolates.- Rye c. c. of Hodgkin disease according to lymphocyte predominance, nodular sclerosing, mixed cellularity, and lymphocyte depletion types. [Rye, NY, 1965]- Salter-Harris c. of epiphysial plate injuries the c. of epiphysial plate injuries into five groups (I to V), according to the pattern of damage to epiphysis, physis, and/or metaphysis; the c. correlates with different prognoses regarding the effects of the injury on subsequent growth and subsequent deformity of the epiphysis.- Tessier c. an anatomical c. of facial, craniofacial, and laterofacial clefts that utilizes the orbit as the primary structure for reference. Fifteen locations for clefts are differentiated.
* * *clas·si·fi·ca·tion .klas-(ə-)fə-'kā-shən n1) the act or process of classifying2) systematic arrangement of animals and plants in groups or categories according to established criteria specif TAXONOMY (2)
* * *clas·si·fi·ca·tion (klas″ĭ-fĭ-kaґshən) the systematic arrangement of similar entities on the basis of certain differing characteristics.
Medical dictionary. 2011.