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Medical Dictionary - Dictionary of Medicine and Human Biology


Medical Dictionary


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dentinogenesis (den′ti-no-jen′e-sis)
The process of dentin formation in the development of teeth. [dentin + G. genesis, production] d. imperfecta [MIM*125490 & MIM*125500] an autosomal dominant disorder of the teeth characterized clinically by translucent gray to yellow-brown teeth involving both primary and permanent dentition; the enamel fractures easily, leaving exposed dentin, which undergoes rapid attrition; radiographically, the pulp chambers and canals appear obliterated and the roots are short and blunted; sometimes occurs in association with osteogenesis imperfecta; autosomal dominant inheritance. SYN: hereditary opalescent dentin (1) .

dentinoid (den′ti-noyd)
1. Resembling dentin. 2. SYN: dentinoma. [dentin + G. eidos, resembling]

dentinoma (den′ti-no′ma)
A rare benign odontogenic tumor consisting microscopically of dysplastic dentin and strands of epithelium within a fibrous stroma. SYN: dentinoid (2) . [dentin + G. -oma, tumor]

dentinum (den′ti-num) [TA]
SYN: dentine. [L. dens, tooth]

dentiparous (den-tip′a-rus)
Tooth-bearing. [denti- + L. pario, to bear]

dentist
A legally qualified practitioner of dentistry.

dentistry (den′tis-tre)
The healing science and art concerned with the structure and function of the oral-facial complex, and with the prevention, diagnosis, and treatment of deformities, pathoses, and traumatic injuries thereof. SYN: odontology, odontonosology. community d. public health d., with an academic base, emphasizing the professional obligation to foster the delivery of prevention, education, and care to populations. esthetic d. a field of d. concerned especially with the appearance of the dentition as achieved through its arrangement, form, and color. forensic d. 1. the relation and application of dental facts to legal problems, as in using the teeth for identifying the dead; 2. the law in its bearing on the practice of d.. SYN: dental jurisprudence, forensic odontology, legal d.. legal d. SYN: forensic d.. operative d. usually, the individual restoration of teeth by means of metallic or nonmetallic materials. SYN: restorative d.. pediatric d. SYN: pedodontics. preventive d. a philosophy and method of dental practice that seeks to prevent the initiation, progression, and recurrence of dental disease. prosthetic d. SYN: prosthodontics. public health d. that specialty of d. concerned with the prevention and control of dental diseases and promotion of oral health through organized community efforts. restorative d. SYN: operative d..

dentition (den-tish′un)
The natural teeth, as considered collectively, in the dental arch; may be deciduous, permanent, or mixed. [L. dentitio, teething] artificial d. SYN: denture (1) . deciduous d. SYN: deciduous tooth. delayed d. delayed eruption of the teeth. first d. SYN: deciduous tooth. mandibular d. SYN: mandibular dental arcade. maxillary d. SYN: maxillary dental arcade. natural d. d.. primary d. SYN: deciduous tooth. retarded d. d. in which growth phenomena such as calcification, elongation, and eruption occur later than in the average range of normal variation as a result of some systemic metabolic dysfunction ( e.g., hypothyroidism). secondary d. SYN: permanent tooth. succedaneous d. SYN: permanent tooth.

dento-
See dent-.

dentoalveolar (den′to-al-ve′o-lar)
Usually, denoting that portion of the alveolar bone immediately about the teeth; used also to denote the functional unity of teeth and alveolar bone.

dentode (den′tod)
An exact reproduction of a tooth on a gnathographically mounted cast.

dentoid (den′toyd)
SYN: odontoid (1) . SEE ALSO: dentiform. [dent- + G. eidos, resemblance]

dentolegal (den-to-le′gal)
Relating to both dentistry and the law. See forensic dentistry.

dentoliva (den-to-li′va)
Rarely used term for oliva. [L. dens, tooth, + oliva, olive]

dentulous (den′tu-lus)
Having natural teeth present in the mouth.

denture (den′tur)
1. An artificial substitute for missing natural teeth and adjacent tissues. SYN: artificial dentition. 2. Sometimes used to denote the dentition of animals. bar joint d. SYN: overlay d.. complete d. a dental prosthesis which is a substitute for the lost natural dentition and associated structures of the maxillae or mandible. SYN: full d.. design d. a planned visualization of the form and extent of a dental prosthesis, made after a study of all factors involved. fixed partial d. a restoration of one or more missing teeth which cannot be readily removed by the patient or dentist; it is permanently attached to natural teeth or roots which furnish the primary support to the appliance. SYN: bridge (3) , fixed bridge. full d. SYN: complete d.. immediate d. a complete or partial d. constructed for insertion immediately following the removal of natural teeth. SYN: immediate insertion d.. immediate insertion d. SYN: immediate d.. implant d. a d. that receives its stability and retention from a substructure which is partially or wholly implanted under the soft tissues of the d. basal seat. SEE ALSO: implant d. substructure, implant d. superstructure, subperiosteal implant. interim d. a dental prosthesis to be used for a short interval of time for reasons of esthetics, mastication, occlusal support, or convenience, or to condition the patient to accept an artificial substitute for missing natural teeth until more definite prosthetic dental treatment can be provided. SYN: provisional d., temporary d.. overlay d. a complete d. that is supported by both soft tissue and natural teeth that have been altered so as to permit the d. to fit over them. The altered teeth may have been fitted with short or long copings, locking devices, or connecting bars. SYN: bar joint d., hybrid prosthesis, overdenture, telescopic d.. partial d. a dental prosthesis which restores one or more, but less than all, of the natural teeth and/or associated parts and which is supported by the teeth and/or the mucosa; it may be removable or fixed. SYN: bridgework. partial d., distal extension a removable partial d. that is retained by natural teeth at one end of the d. base segments only, and in which a portion of the functional load is carried by the residual ridge. provisional d. SYN: interim d.. removable partial d. a partial d. which supplies teeth and associated structures on a partially edentulous jaw, and which can be readily removed from the mouth. SYN: removable bridge. telescopic d. SYN: overlay d.. temporary d. SYN: interim d.. transitional d. a partial d. which is to serve as a temporary prosthesis to which teeth will be added as more teeth are lost, and which will be replaced after postextraction tissue changes have occurred; a transitional d. may become an interim d. when all of the teeth have been removed from the dental arch. treatment d. a dental prosthesis used for the purpose of treating or conditioning the tissues which are called upon to support and retain a d. base. trial d. a setup of artificial teeth so fabricated that it may be placed in the patient's mouth to verify esthetics, for the making of records, or for any other operation deemed necessary before final completion of the d.. SYN: wax model d.. wax model d. SYN: trial d..

denture service
Those procedures performed in the diagnosis, construction, and maintenance of artificial substitutes for missing natural teeth.

denturist (den′tur-ist)
A dental technician who fabricates and fits dentures without supervision of a dentist.

Denucé
Jean L.P., French surgeon, 1824–1889. See Denucé ligament.

denucleated (de-noo′kle-a-ted)
Deprived of a nucleus.

denudation (den-u-da′shun)
Depriving of a covering or protecting layer; the act of laying bare, as in the removal of the epithelium from a surface. [L. de-nudo, to lay bare, fr. de, from, + nudus, naked]

denude (de′nood)
To perform denudation.

Denys
Joseph, Belgian bacteriologist, 1857–1932. See D.-Leclef phenomenon.

deodorant (de-o′der-ant)
1. Eliminating or masking a smell, especially an unpleasant one. 2. An agent having such an action; especially a cosmetic combined with an antiperspirant. SYN: deodorizer. [L. de- priv. + odoro, pp. -atus, to give an odor to, fr. odor, a smell]

deodorize (de-o′der-iz)
To use a deodorant.

deodorizer (de-o′der-iz-er)
SYN: deodorant (2) .

deontology (de-on-tol′o-je)
The study of professional ethics and duties. [G. deon (deont-), that which is binding, pr. part. ntr. of dei, (impers.) it behooves, fr. deo, to bind, + logos, study]

deorsumduction (de-or′sum-duk′shun)
Rotation of one eye downward. SYN: infraduction. [L. deorsum, downward, + duco, to lead]

deossification (de-os′i-fi-ka′shun)
Removal of the mineral constituents of bone. See demineralization. [L. de, from, + os, bone, + facio, to make]

deoxidation (de′oks-i-da′shun)
Depriving a chemical compound of its oxygen.

deoxidize (de-oks′i-diz)
To remove oxygen from its chemical combination.

deoxy-
Prefix to chemical names of substances to indicate replacement of an –OH by an H. The older desoxy- has been retained in some instances.

deoxyadenosine (dA, dAdo) (de-oks′e-a-den′o-sen)
2′-Deoxyribosyladenine, one of the four major nucleosides of DNA (the others being deoxycytidine, deoxyguanosine, and thymidine). The 5′ derivative is also an important component of one form of vitamin B12. D. accumulates in individuals with severe combined immunodeficiency disease.

deoxyadenosine methylase
SYN: dam methylase.

5′-deoxyadenosylcobalamin (de-oks′e-a-den-o-sil-ko-bal′a-min)
An active coenzyme form of vitamin B12; required in the conversion of methylmalonyl-CoA to succinyl-CoA. A deficiency of d. will result in methylmalonic acidemia.

deoxyadenylic acid (dAMP) (de-oks′e-ad-en-il′ik)
Deoxyadenosine monophosphate, a hydrolysis product of DNA, differing from adenylic acid in containing deoxyribose in place of ribose. SYN: adenine deoxyribonucleotide.

deoxybarbiturate (de-oks-e-bar-bit′ur-at)
A barbiturate compound lacking the oxygen atom at the #2 position in the ring; example of a d. is the antiepileptic drug, primidone. SEE ALSO: barbiturate.

deoxycholate (DOC) (de-oks-e-ko′lat)
A salt or ester of deoxycholic acid.

deoxycholic acid (de-oks-e-ko′lik)
7-D.; 3α,12α-dihydroxy-5β-cholanic acid;a bile acid and choleretic; used in biochemical preparations as a detergent.

deoxycoformycin (de′oks-e-co-for-mi′sin)
A purine analog which acts as an antimetabolite; potent inhibitor of adenosine deaminase. Used as an antineoplastic agent. SEE ALSO: pentostatin.

2-deoxycoformycin
SYN: pentostatin.

deoxycorticosterone (DOC) (de-oks′e-kor-ti-kos′ter-on)
An adrenocortical steroid, principally a biosynthetic precursor of corticosterone, that occasionally appears in adrenocortical secretions; a potent mineralocorticoid with no appreciable glucocorticoid activity. SYN: 21-hydroxyprogesterone, cortexone, deoxycortone, desoxycortone. d. acetate acetate salt used for intramuscular injection for replacement therapy of the adrenocortical steroid. d. pivalate pivalate salt of the steroid.

deoxycortone (de-oks-e-kor′ton)
SYN: deoxycorticosterone.

deoxycytidine (de-oks-e-si′ti-den)
2′-Deoxyribosylcytosine, one of the four major nucleosides of DNA (the others being deoxyadenosine, deoxyguanosine, and thymidine).

deoxycytidylic acid (dCMP) (de-oks′e-si-ti-dil′ik)
Deoxycytidine monophosphate, a hydrolysis product of DNA.

deoxyepinephrine (de-oks′e-ep-i-nef′ren)
A sympathomimetic amine used as a vasoconstrictor.

deoxyguanosine (de-oks-e-gwan′o-sen)
2′-Deoxyribosylguanine, one of the four major nucleosides of DNA (the others being deoxyadenosine, deoxycytidine, and thymidine). Found to accumulate in individuals with purine nucleoside phosphorylase deficiency.

deoxyguanylic acid (dGMP) (de-oks-e-gwan-il′ik)
Deoxyguanosine monophosphate, a hydrolysis product of DNA. SYN: guanine deoxyribonucleotide.

deoxyhexose (de-oks-e-heks′os)
A 6-carbon deoxy-sugar in which one OH is replaced by H.

deoxynucleoside (de-oks′e-noo′kle-o-sid)
See deoxyribonucleoside.

deoxynucleotide (de-oks′e-noo′kle-o-tid)
See deoxyribonucleoside.

deoxypentose (de-oks-e-pen′tos)
A 5-carbon deoxy-sugar in which one OH is replaced by H.

deoxyriboaldolase (de-oks′e-ri-bo-al′do-las)
SYN: deoxyribosephosphate aldolase.

deoxyribodipyrimidine photolyase (de-oks′e-ri′bo-di-pi-rim′i-den)
An enzyme in yeast that is activated by light, whereupon it can reverse a previous photochemical reaction by cleaving the cyclobutane ring of the thymine dimer. SYN: dipyrimidine photolyase, photoreactivating enzyme.

deoxyribonuclease (DNAse, DNAase, DNase) (de-oks′e-ri-bo-noo′kle-as)
Any enzyme (phosphodiesterase) hydrolyzing phosphodiester bonds in DNA. SEE ALSO: endonuclease, nuclease. acid d. SYN: d. II. d. I, DNase I an endonuclease that cleaves primarily double-stranded DNA to a mixture of oligodeoxyribonucleotides, each ending in a 5′-phosphate; streptodornase is a similar enzyme. Under appropriate conditions, it can produce single-strand nicks in DNA; used in nick translation and in the mapping of hypersensitive sites. SYN: pancreatic d., thymonuclease. d. II, DNase II an endonuclease that cleaves both strands of native DNA (as well as single-stranded DNA) to produce a mixture of oligodeoxynucleotides, each ending in a 3′-phosphate. SYN: acid d.. pancreatic d. SYN: d. I. d. S1 SYN: endonuclease S1 Aspergillus. spleen d. former name for micrococcal endonuclease.

deoxyribonucleic acid (DNA) (de-oks′e-ri′bo-noo-kle′ic)
The type of nucleic acid containing deoxyribose as the sugar component and found principally in the nuclei (chromatin, chromosomes) and mitochondria of animal and plant cells, usually loosely bound to protein (hence the term deoxyribonucleoprotein); considered to be the autoreproducing component of chromosomes and of many viruses, and the repository of hereditary characteristics. Its linear macromolecular chain consists of deoxyribose molecules esterified with phosphate groups between the 3′- and 5′-hydroxyl groups; linked to this structure are the purines adenine (A) and guanine (G) and the pyrimidines cytosine (C) and thymine (T). DNA may be open-ended or circular, single- or double-stranded, and many forms are known, the most commonly described of which is double-stranded, wherein the pyrimidines and purines cross-link through hydrogen bonding in the schema A-T and C-G, bringing two antiparallel strands into a double helix. Chromosomes are composed of double-stranded DNA; mitochondrial DNA is circular. A-DNA a form of DNA in which the helix is right-handed and the overall appearance is short and broad. antisense DNA the strand of DNA complementary to the one bearing the genetic message and from which it may be reconstructed. A DNA sequence complementary to a portion of mRNA. Used as potential therapeutic to stop transcription or translation of pathogens or inappropriately expressed host gene. B-DNA a form of DNA in which the helix is right-handed and the overall appearance is long and thin. blunt-ended DNA double-stranded DNA in which at least one of the ends has no unpaired bases. competitor DNA dNA from a test organism that is denatured and then used in in vitro hybridization experiments in which it competes with DNA (homologous) from a reference organism; used to determine the relationship of the test organism to the reference organism. complementary DNA (cDNA) 1. single-stranded DNA that is complementary to messenger RNA; 2. dNA that has been synthesized from mRNA by the action of reverse transcriptase. extrachromosomal DNA dNA that occurs naturally outside of the nucleus ( e.g., mitochondrial DNA). DNA fingerprinting a technique used to compare individuals by molecular genotyping. DNA isolated from a biological specimen is digested and fractionated. Southern hybridization with a radiolabeled repetitive DNA provides an autoradiographic pattern unique to the individual. SYN: DNA profiling, DNA typing.A technique developed in 1985 for comparing sets of DNA by locating identical sequences of nucleotides. Forensic applications of DNA fingerprinting are based on the premise that no 2 persons have exactly the same genetic makeup. The most distinctive features of an individual's genome are not the genes themselves but the variable number of tandem repeats (VNTRs) that occur between genes. While these do not transmit genetic information, they are highly consistent within the cells of an individual and highly variable from one individual to another. In DNA fingerprinting, the specimen is split into nucleotide fragments by treatment with restriction enzymes and then subjected to gel electrophoresis so as to yield a characteristic pattern of banding. Radioactive probes, composed of short nucleotide sequences (10–15 base pairs), then identify sites of tandem repeats and hybridize with them. Comparing the results from 2 or more DNA sources reveals their degree of relatedness. DNA fingerprinting offers a statistical basis for evaluating the probability that samples of blood, hair, semen, or tissue have originated from a given person. It also offers a means of determining lineages of humans and animals. The U.S. National Academy of Sciences has cautiously endorsed the use of DNA fingerprints as criminal evidence, while calling for further research and standardization of the technique. genomic DNA dNA that contains both introns and exons. junk DNA selfish DNA; that portion of DNA that is not transcribed and expressed, comprising a major fraction of the base pairs of the human genome; its function is not known. DNA ligase an enzyme that leads to the formation of a phosphodiester bond at a break of one strand in duplex DNA; a part of the DNA repair system. linker DNA the DNA found between nucleosomes on chromatin; since it is not complexed to proteins as strongly as other forms of DNA, it is accessible to exonuclease hydrolysis. DNA nucleotidylexotransferase an enzyme that can catalyze the addition of a nucleotide, presented as a nucleoside triphosphate, on a DNA or similar polydeoxynucleotide; has been used in DNA recombination studies to add nucleotides to form homopolymer tails. SYN: terminal addition enzyme, terminal deoxynucleotidyltransferase. palindromic DNA a segment of DNA in which the sequence is symmetrical about its midpoint. DNA polymerase nucleotidyltransferases. DNA profiling SYN: DNA fingerprinting. recombinant DNA altered DNA resulting from the insertion into the chain, by chemical, enzymatic, or biologic means, of a sequence (a whole or partial chain of DNA) not originally (biologically) present in that chain. repetitive DNA a segment of DNA that consists of a linear array of multiple copies of the same sequence of nucleotides. satellite DNA dNA in the satellite regions of acrocentric chromosomes. sticky-ended DNA double-stranded DNA in which one of the strands protrudes from the other strand ( I.E., has a number of unpaired bases) at one end or more. DNA typing SYN: DNA fingerprinting. Z-DNA a form of DNA in which the helix is left-handed, and the overall appearance is elongated and slim. zero time-binding DNA DNA that has become the duplex form at the start of a reassociation process.

deoxyribonucleoprotein (DNP, Dnp) (de-oks′e-ri-bo-noo′kle-o-pro′ten)
The complex of DNA and protein in which DNA is usually found upon cell disruption and isolation.

deoxyribonucleoside (de-oks′e-ri-bo-noo′kle-o-sid)
A nucleoside component of DNA containing 2-deoxy-d-ribose; the condensation product of deoxy-d-ribose with purines or pyrimidines.

deoxyribonucleotide (de-oks′e-ri-bo-noo′kle-o-tid)
A nucleotide component of DNA containing 2-deoxy-d-ribose; the phosphoric ester of deoxyribonucleoside; formed in nucleotide biosynthesis.

deoxyribose (de-oks-e-ri′bos)
A deoxypentose, 2-deoxy-d-ribose being the most common example, occurring in DNA and responsible for its name. d. phosphate deoxyribonucleotide.

deoxyribosephosphate aldolase (de-oks′e-ri-bos-fos′fat)
An enzyme catalyzing cleavage of 2-deoxy-d-ribose 5-phosphate to d-glyceraldehyde 3-phosphate and acetaldehyde. SYN: deoxyriboaldolase.

deoxyriboside (de-oks-e-ri′bo-sid)
Deoxyribose combined via its 1-O atom with a radical derived from an alcohol; not to be confused with deoxyribosyl compounds such as deoxyribonucleosides. Cf.:deoxyribosyl.




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