Oral Histo Vocab

Front 1

Accessory canals

Back 1

Canals leading from the radicular pulp laterally through the root dentin to the periodontal tissue. They are particularly numerous in the apical third of the root.

Front 2

Accessory root canal

Back 2

Subordinate chamber of the dental pulp lying within the root portion of the tooth.

Front 3

Accellular cementum

Back 3

That part of the cementum covering one third to one half of the root of a tooth adjacent to the cementoenamel junction. It usually is opposed by a layer of cellular cementum. It consists of collagenous fibers and a uniform ground substance but has no cellular components.

Front 4

Acid hydrolases

Back 4

The content of lysosomes, the enzymes specialized for intracerular degradation.

Front 5

Acinus, salivary

Back 5

A small terminal saclike dilation found in salivary glands.

Front 6

Acquired cuticle

Back 6

Aceellular organic film that is deposited on the surface of teeth after eruption. Microscopically, it is made up of several layers.

Front 7

Adrenergic

Back 7

Nerve fibers that secrete norepinepherine at a synapse usually associated with sympathetic nerve fibers.

Front 8

Agonist

Back 8

A substance that produces an effect similar to the naturally occurring substance.

Front 9

Allantois

Back 9

Fetal tubular diverticulum developing from the hindgut. In humans, it is vestigial and contributes to the formation of the umbilical cord and placenta.

Front 10

Alloplastic material

Back 10

Material suitable for implantation that is not from the human body, such as metal, plastic, or mineral.

Front 11

Alveolar bone

Back 11

The ridge of bone on the surface of the body of the maxilla and mandible. This term is applied to the tooth-bearing part of the mandible and maxma, as it contains the tooth sockets.

Front 12

Alveolar bone proper

Back 12

A thin lamina of bone that surrounds and supports the roots of the teeth and gives attachment to principal fibers of the periodontal ligament.

Front 13

Alveolar crest fibers

Back 13

Those principal fibers of the periodontal ligament extending between the crest of the alveolar bone and the neck of the tooth.

Front 14

Alveolar fimdus

Back 14

Bottom or base of the alveolar bone proper, lining the tooth socket.

Front 15

Ameloblast

Back 15

One of the cells of the inner layer lining the cap of the enamel organ. These cells give rise to the enamel of the teeth.

Front 16

Amelogenesis

Back 16

The process of production and development of enamel.

Front 17

Amelogenin

Back 17

A hydrophobic proline-rich protein found in newly deposited enamel matrix. Its molecular weight is about 25,000 daltons. Amelogenins are lost during maturation of enamel.

Front 18

Amylase

Back 18

Enzyme that catalyzes the hydrolysis of starch into smaller, water-soluble carbohydrates. In mammals, there are two forms: (1) pancreatic amylase, found in the pancreatic juice, and (2) salivary amylase (ptyalin), found in the saliva.

Front 19

Anastomosis

Back 19

A communication or union between two structures.

Front 20

Anatomical crown

Back 20

That portion of the tooth that is covered by enamel; the true crown.

Front 21

Angiogenesis

Back 21

Refers to the process by which capillaries develop budlike structures that will form new capillary branches.

Front 22

Ankyloglossia

Back 22

Restricted movement of the tongue, which results in speech difficulty.

Front 23

Ankylosed

Back 23

Stiffened; bound by adhesions; fused; denoting a joint in a state of ankylosis; rigid fixation of a tooth to the surrounding bony alveolus as a result of periodontal membrane ossification.

Front 24

Antibody

Back 24

An immunoglobulin molecule that reacts with or binds to the substance (antigen) that induced its synthesis. These proteins are produced by plasma cells.

Front 25

Antigen

Back 25

A substance that is recognized as foreign by the body.

Front 26

Aortic arches

Back 26

A series of arterial channels encircling the embryonic pharynx in the mesenchyme of the bronchial arches.

Front 27

Apical cementum

Back 27

Cementum deposited on the apical region of the tooth root.

Front 28

Apical foramen

Back 28

Opening at the apex of the root of a tooth that gives passage to the nerves and blood vessels.

Front 29

Arches, aortic

Back 29

See Aortic arches.

Front 30

Arches, branchial

Back 30

See Branchial arrhes.

Front 31

Apocrine

Back 31

Sweat gland, a large tubular exocrine gland that accumulates secretion in its cell apices and ruptures the surface membrane during the secretary activity.

Front 32

Articular disc

Back 32

Of the temporomandibular joint; the fibrous disc that separates the joint into upper and lower cavities.

Front 33

Attached gingiva

Back 33

That part of the oral mucosa which is firmly bound to the tooth and alveolar process.

Front 34

Attached pulp stones

Back 34

Mineralized tissues that are partly fused with the dentin of the coronal or root pulp.

Front 35

Basal lamina

Back 35

Structural scaffolding composed of glycosaminoglycans, glycoproteins, and collagen; synthesized by epithelial cells throughout the body; probably plays an important role in developing systems and in homeostasis of adult epithelia. Thickening of the basal laminae of the body occurs in diabetes memtus and other pathologic conditions.

Front 36

Bell stage

Back 36

Tooth developmental stage characterized by the differentiation of inner enamel epithelial cells into ameloblasts and the formation of the crown outline by these cells.

Front 37

Bifid tongue

Back 37

Split or cleft; separating the tongue into two parts.

Front 38

Biocompatibility

Back 38

The ability of a material to perform with an appropriate host respose in a specific situation. The material may he required to trigger or elicit a biological response from the body, such as bone formation or protein adhesion, without being harmftd to the tissues.

Front 39

Biological age

Back 39

The maturational age; not the chronological age, but the dental age/skeletal age.

Front 40

Birbeck's granule

Back 40

A specific granule located in Langerhai;s cells.

Front 41

Birth

Back 41

Passage of the child from the uterus to the outside world; the act of being bom.

Front 42

Blastocyst

Back 42

The postmorula stage of development; a blastula with a fluid-fired cavity.

Front 43

Bodily movement of a tooth

Back 43

When force is applied through the center of resistance the tooth moves in a bodily fashion. All parts move the same amount and in the same direction.

Front 44

Bone

Back 44

Mineralized animal tissue consisting of an organic matrix of cells and fibers of collagen impregnated with mineral matter, chiefly calcium phosphate and calcium carbonate.

Front 45

Bradykinin

Back 45

A kinin composed of nine amino acids secreted in response to the action of trypsin on a globulin of blood plasma.

Front 46

Branchial

Back 46

Barlike; resembling the gills of fish.

Front 47

Branchial arch cartilages

Back 47

One of the carfilages formed in a bronchial arch of the embryo.

Front 48

Branchial arches

Back 48

One of a series of mesodermal thickenings between the bronchial clefts, appearing in higher forms only vestigially. During embryonic stages they contribute to the formation of the face, jaws, and neck.

Front 49

Buccinator muscle

Back 49

Muscle forming principal substance of the cheek.

Front 50

Bud stage

Back 50

Initial stage of tooth development; the enamel organ develops from this structure. The dental papilla and the dental sac enclose the bud.

Front 51

Bundle bone

Back 51

Specialized bone lining the tooth socket into which the fibers of the periodontal ligament penetrate; synonymous with the radiographic term lamina dura.

Front 52

Calculus

Back 52

An abnormal concretion within the body, usually formed of inorganic matter and often deposited around a minute fragment of inorganic material, the nucleus.

Front 53

Calculus, dental

Back 53

Hard stonelike concretion formed on the teeth or prosthesis. It varies in color from creamy yellow to black and is mostly composed of calcium phosphate.

Front 54

Calvarium

Back 54

Skullcap; the superior, domelike portion of the cranium.

Front 55

Canaliculi

Back 55

Small microscopic spaces that contain cellular projections of osteocytes and cementocytes. In dentin, the spaces occupied by branches from the main dentinal tubule.

Front 56

Cap stage

Back 56

Tooth development, an early stage in enamel organ formation; follows the bud stage.

Front 57

Caries, dental

Back 57

Localized, progressively destructive disease of the teeth that starts at the external surface (enamel) with the apparent dissolution of the inorganic components by organic acids.

Front 58

Cartilage

Back 58

Connective tissue characterized by its nonvascularity and firm consistency. There are three kinds of cartilage: hyaline cartilage, fibrocartilagee, and elastic cartilage.

Front 59

Catecholamine

Back 59

One of a group of similar compounds that have a sympathomimetic action.

Front 60

Cell differentiation

Back 60

An increase in morphologic or chemical heterogenicity.

Front 61

Cell proliferation

Back 61

The developmental process in which cells pass through the cell cycle, with parent cells dividing to form two daughter cells and thereby increasing the number of cells in the tissue or organ.

Front 62

Cell rests (Malassez)

Back 62

The epithelial remnants of the root sheaths found in the periodontal ligament.

Front 63

Cell-free zone

Back 63

Relatively cell-free layer adjacent to odontoblasts, overlying the cell-rich zone of the dental pulp and composed of delicate fibrils embedded in the ground substance.

Front 64

Cell-rich zone

Back 64

Layer of the dental pulp situated between the pulp core and the cell-free zone, which is richly supplied with cellular elements, blood vessels, and nerves.

Front 65

Cellular cementum

Back 65

That part of the cementum covering the apical one half to two thirds of the root of a tooth. It is usually opposed by a layer of acellular cementum. It contains cementocytes embedded in the calcffied matrix.

Front 66

Cementicles

Back 66

Calcified spherical bodies composed of cementum either lying free within the periodontal ligament attached to the cementum or embedded within it.

Front 67

Cementoblast

Back 67

Connective tissue cell type responsible for the formation of cementum.

Front 68

Cementocyte

Back 68

A cell found in the lacuma of cellular cementum, from 8 itm to more than 15 itm in diameter, with a wide variety of shapes from round to oval to flattened. Numerous cytoplasmic processes extend from its free surface.

Front 69

Cementum

Back 69

Bonelike connective tissue that covers the tooth from the cementocnamel junction to and surrounding the apical foramen.

Front 70

Cementum-enamel (cementoenamel) junction

Back 70

It represents the boundary between enamel and cementum that lies at the cervic of the tooth. These two tissues may overlap or be slightly separated.

Front 71

Cervical loop

Back 71

Growing free border of the enamel organ. The outer and inner enamel epithelial layers are continuous and reflected into one another.

Front 72

Cervix

Back 72

The portion of the tooth that lies at the border of the anatomical crown and root of the tooth. It is often at the cementum-enamel junction.

Front 73

Chemotaxis

Back 73

The movement of cells following a concentration gradient (moving towards higher concentration) of a chemical substance.

Front 74

Choanae

Back 74

Paired openings between the nasal cavity and nasopharynx.

Front 75

Cholinergic nerves

Back 75

Nerve fibers that secrete acetylcholine at a synapse primarily associated with postganglionic parasympathetic fibers.

Front 76

Chorda Vmpani

Back 76

A branch of the facial nerve that joins the lingual nerve for parasympathetic supply to the sublingual and submandibular glands.

Front 77

Chondrocranium

Back 77

Carfilaginous skull; the embryonic skull before ossification.

Front 78

Chronologic age

Back 78

Record of time elapsed since birth.

Front 79

Circumpulpal dentin

Back 79

Inner portion of the dentin located near the pulp organ of the tooth.

Front 80

Circumvallate papilla

Back 80

Papilla vallata; one of eight or ten projections from the dorsum of the tongue that form a Vshaped row anterior to the sulcus terminals. Each is surrounded by a circular trench having a slightly raised outer wall.

Front 81

Cleft lip

Back 81

A congenital defect of the lip, usually the upper lip. Failure of the median nasal and maxillary process to fuse.

Front 82

Cleft palate

Back 82

Palatum fissum; a congenital fissure in the median line of the pakw or lateral to the prem@ process or both. It usually is associated with cleft hp.

Front 83

Clinical crown

Back 83

That portion of the crown exposed above the gingiva and visible in the oral cavity.

Front 84

Clinical eruption

Back 84

Emergence of the crown of a tooth, that portion of which can be observed clinically.

Front 85

Cocci

Back 85

Bacteria with round, spheroidal, or ovoid form, including Microcossus, gonococcus, meningococcus, Staphylococcu.s, streptococcus, and pneumococcus.

Front 86

Col

Back 86

Valleyhke depression in the facial lingual plane of the interdental gingiva. It conforms to the shape of the interproximal contact area.

Front 87

Collagen

Back 87

White fibers of the corium of the skin, tendon, and other connective tissue- The fiber is composed of fibrils bound together with interfibrillar cement; the fibrils are, in turn, formed of ultramicroscopic filaments. An albumoid found in connective tissue, bone, and cartilage and notable for its high content of the amino acids glycine, proline, and hydroxyproline.

Front 88

Collagen fiber

Back 88

High-molecular-weight protein composed of a number of structural types that vary in diameter from less than I pin to about 12 14m and usually are arranged in bundles.

Front 89

Compact bone

Back 89

Hard, oftmal, more highly calcified than cancellous (spongy) portion of bone.

Front 90

Complement

Back 90

A group of proteins that react with the antibody-antigen complex producing mediators of inflammation and causing death of foreign cells.

Front 91

Concha

Back 91

A shell- or scroll-like bone- Anatomically it relates to the turbinate bones projecting into the nasal cavity.

Front 92

Connective tissue adhesion

Back 92

Protein adhesion of connective tissue to other substances such as teeth or alloplastic materials.

Front 93

Connective tissue stroma of salivary glands

Back 93

Capsule and septa formed from mesenchyme and the blood vessels.

Front 94

Constitutive secretion

Back 94

Secretion occurring continuously with molecules transported in vesicles from the Golgi apparatus to the plasma membrane in the presence or absence of secretagogue. Some transport vesicles may bud from the secretary vesicles shuttling proteins to the plasma membrane.

Front 95

Cord growth of salivary glands

Back 95

Solid cord of epithelial cells that characterizes an early stage of development of salivary glands.

Front 96

Corpus luteum.

Back 96

Yellow endocrine body, I to 1.5 cm in diameter, formed in the ovary in the site of a ruptured ovarian follicle.

Front 97

Cranial

Back 97

Pertaining to the bones covering the brain on the superior end of the body in humans.

Front 98

Cranial base

Back 98

I-ower portion of the skull constituting the floor of the cranial cavity.

Front 99

Cribriform

Back 99

Bone containing perforations or numerous formina.

Front 100

Crypts

Back 100

Pitlike depressions or tubular recesses.

Front 101

Cuticle, developmental

Back 101

Skin of the teeth consisting of an extremely thin layer of organic material covering the enamel of recently erupted teeth.

Front 102

Cuticle, primary

Back 102

A thin film on the enamel of an unerupted tooth. A product of the degenerating ameloblasts.

Front 103

Cyclic AMP (cAMP)

Back 103

Adenosine 3':5!cychc phosphate; the second or intracellular messenger of target cells. Hormones or pharmacologic agents interact and bind to a membrane-bound receptor associated with an adenyl cyclase enzyme system. Adenyl cyclase catalyzes the conversion of ATP to AMR

Front 104

Cystic fibrosis

Back 104

Lethal genetic disease characterized by a generalized dysfunction of exocrine glands throughout the body and therefore resulting in digestive and pulmonary problems.

Front 105

Cytodifferentiation

Back 105

The process by which cells in the developing tooth evolve and gain functional and morphological differences.

Front 106

Cytokines

Back 106

A group of nonantibody molecules produced by cells that function to influence and signal other cells. The principal function is the induction of cell division and the regulation of differentiation.

Front 107

Dead tracts

Back 107

Empty tubules left after the odontoblasfic processes degenerate.

Front 108

Deciduous dentition

Back 108

Primary teeth or fint-formed set of teeth that undergo exfoliation to provide space for the permanent teeth.

Front 109

Degenerating lamina

Back 109

Lysis and disappearance of the dental lamina, characteristic of teeth in the bell stage of development.

Front 110

Demilune (serous demilune)

Back 110

Half-moon or crescentshaped serous cells of a mixed-type acinus that form a cap over the ends of the mucous acinar cells.

Front 111

Dental lamina.

Back 111

Horseshoe-shaped epithelial bands that traverse the upper and lower jaws and give rise to the ectodermal portions of the teeth.

Front 112

Dental papilla

Back 112

Formative organ of the dentin and primordium of the pulp.

Front 113

Dental plaque

Back 113

Organic deposit on the surface of teeth. Site of growth of bacteria or nucleus for formation of dental calculus.

Front 114

Dental pulp (endodontia)

Back 114

Soft tissue contained within the pulp cavity, consisting of connective tissue and containing blood vessels, nerves, and lymphatics.

Front 115

Dental sac (follicle)

Back 115

Area surrounding the developing tooth that produces the alveolar bone, cementum, and periodontal ligament and consists of (ecto) mesenchymal cells and fibers that surround the dental papilla and the enamel organ.

Front 116

Denticles

Back 116

A calcified structure found in the pulp of a tooth.

Front 117

Dentin

Back 117

Body of the tooth; surrounds the pulp and underlies the enamel on the crown and the cementum on the roots of the teeth. About 20% is organic matrix, mostly collagen, and 10% is water. The inorganic fraction (70%) is mainly hydroxyapatite, with some carbonate, magensium, and fluoride. It is yellowish in color.

Front 118

Dentinal tubule

Back 118

The space in dentin that contains or at one time contained an odontoblastic process.

Front 119

Dentinoenamel junction

Back 119

Interface of the enamel and dentin of the crown of a tooth.

Front 120

Dentinogenesis

Back 120

Process of dentin formation in the development of teeth.

Front 121

Desmosome

Back 121

Macula adherens; site of adhesion between two cells, consisting of a dense plate near the cell surface, separated from a similar structure in the adjacent cell by thin layers of extracellular materials believed to have adhesive properties. Intracellular tonofilaments are associated with this structure.

Front 122

Diapedesis

Back 122

The migration of cells like neutrophfls through gaps between endothelial cells.

Front 123

Differentiation

Back 123

Growth associated with or having a distinguishing character or function from the surrounding structures or from the original type; specialization.

Front 124

Diphyodont

Back 124

Having two sets of teeth, as in humans and most mammals.

Front 125

Displacement

Back 125

Change in position of a bone due to growth at its border or movement of an adjacent bone. Change in attachment when one element, radical, or molecule is removed and is replaced by another.

Front 126

Drift

Back 126

The change in position of a bone due to remodeling (apposition on one side and resorption on the other). Movement of a tooth to a position of greater stability.

Front 127

Drug

Back 127

Any substance used as a medicine in the treatment of disease; to give medicine; to narcotize.

Front 128

Duct

Back 128

Tube with well-defined wafls for passage of excretions or secretions.

Front 129

Duct, intercalated

Back 129

The smallest-diameter intralobular duct of salivary glands that conducts saliva from the acinar cells to the striated ducts. These ducts modify salivary secretions.

Front 130

Duct, interlobar

Back 130

Channels located outside lobes of the salivary glands.

Front 131

Duct, intralobar

Back 131

Channels located within lobes of the salivary glands.

Front 132

Duct, striated

Back 132

A type of intralobular duct of the salivary glands that is composed of columnar cells with centrally placed nuclei and striations at the basal ends of cells. These cells modify salivary secretions.

Front 133

Dystrophy

Back 133

Any disorder arising from defective or faulty nutrition.

Front 134

Eccentric growth

Back 134

That process whereby one part of the developing tooth germ remains stationary, while the remainder continues to grow. This leads to a shift in its center.

Front 135

Ectoderm

Back 135

Outer layer of cells of the three primary germ layers; forms nervous system epidermis and derivatives.

Front 136

Ectomesenebyme

Back 136

Neural crest cells, mesectoderm. This term is used to describe cells derived fiom the neural crest and found in the mesodermal tissues. Functions in induction. Forms spinal ganglia, much of the face, and branchial arches.

Front 137

Edema

Back 137

The swelling that results from fluid accumulation within the tissue following a spill of blood constitutents.

Front 138

Edentulous

Back 138

Without teeth, having lost the natural teeth.

Front 139

Eicosanoids

Back 139

A group of compounds that are converted to biologically active substances that act as mediators of inflammation.

Front 140

Embedded pulp stones (denticles)

Back 140

Small calcified masses of dentin appearing as a function of age or trauma. They may protrude from the existing dentin wall into the pulp tissue-

Front 141

Enamel crystals

Back 141

Hydroxyapatite crystals found in enamel rods. They are deposited during tooth mineralization.

Front 142

Enamel lamellae

Back 142

Thin, leaflike structures that extend from the enamel surface toward the dentinoenamel junction. They represent defects or spaces filled entirely or partly with organic material.

Front 143

Enamel organ

Back 143

Originates from the stratified epithelium @g the primitive oral cavity organ; consists of four distinct layers: outer enamel epithelium, stellate reticulum, stratum intermedium, and inner enamel epithelium. The latter becomes the ameloblastic layer.

Front 144

Enamel pearls

Back 144

Enarneloma, a developmental anomaly in which a small nodule of enamel is formed near the cementoenamel junction, usually at the bifurcation zone of molar teeth.

Front 145

Enamel rod

Back 145

One of the structural units Of enamel, extending from the dentinoenamel junction to the surface of the tooth, averaging about 5 um in width and 9 um in height, and normally having a translucent crystalline appearance.

Front 146

Enamel spindles

Back 146

Tubular spaces in enamel found at the dentinoenamel junction in which a terminal extension of the odontoblast processes may be found.

Front 147

Enamel tuft

Back 147

Narrow, ribbonlike structure whose inner end arises at the dentinoenamel junction, extends one third of the distance to the enamel surface, and consists of hypocalcified enamel rods; may be filled with organic substance and extend at near right angles to the dentinoenamel junction.

Front 148

Enamelin

Back 148

An acidic glycosylated phosphoprotein of mature enamel. It has a molecular weight of about 55,000 daltons.

Front 149

Endochondral

Back 149

Relating to the type of formation of bone formed within cartilage and replacing it.

Front 150

Endocrine

Back 150

Refers to glands of internal secretion that release their secretary product(s) (hormones) directly into the bloodstream rather than through a duct system.

Front 151

Endosseous implants

Back 151

Implants that are embedded in bone and fixed throughout the entire length of the implant. The various implant types are screw, blade, and cylinder.

Front 152

Entactin

Back 152

An extra cellulax matrix glycoprotein associated with the basal lamina.

Front 153

Epidermal growth factor (EGF)

Back 153

A small peptide (molecular weight = 6045) originally isolated from the male mouse submandibular gland and now known to have a very wide distribution in the body. EGF stimulates cell proliferation and/or differentiation in various organs and tissues through EGF receptors that activate tyrosine-specific proteins kinases.

Front 154

Epimers

Back 154

Dorsal form of a myotome that forms muscles innervated by the dorsal ramus of the spinal nerve.

Front 155

Epiphyseal plate of condylar head

Back 155

Cartilage of the head of the mandibular condyle, a growth site.

Front 156

Epithelial aunchment

Back 156

Dentogingival junction attachment of the gingival epithelium with the tooffs surface. The basal lamina of the epitheleum is attached by means of hemidesmosomes.

Front 157

Epithelial cell rests

Back 157

Remains of (Hertwig's) root sheath. The epithelial cells that cover the roots during root development. Later, they are located in the periodontal ligament near the surface of the cementum as groups of cells called "rests" There are three types: proliferating, resting, and degenerating. Occasionally, they develop into the dental cysts.

Front 158

Epithelial diaphragm

Back 158

Formed by the root sheath at the beginning of root development; important in formation of the root. It fmally serves to narrow the width of the cervial opening of the root.

Front 159

Epithelial pearls

Back 159

Discrete, rounded or ovoid groups of epithelial cells, frequently keratinized, found in the lamina propria. The cells are arranged in a whorled or concentrically laminated pattern, with polygonal cells centrally flattened and with more mature cells found peripherally. Most often found in the midline of the palate and are remnants of epithelium in the line of fusion.

Front 160

Epithehum

Back 160

Cellular, avascular layer covering all the free surfaces of the body internal and external and the lining of vessels. Consists of cells and a small amount of intercellular substance. Includes the glands and other structures derived therefrom.

Front 161

Epithelium, inner enamel

Back 161

The cells that line the concavity of the enamel organ in the cap and early bell stages of tooth development and differentiate into ameloblasts.

Front 162

Epithelium, outer enamel

Back 162

Cuboidal peripheral cells of the cap or the bell stage of tooth development that line the convexity of the cap.

Front 163

Eruption, teeth

Back 163

Appearance of teeth in the oral cavity; a stage coordinated with root growth and maturation of tissues surrounding the tooth.

Front 164

Esterase

Back 164

The enzyme responsible for catalyzing the hydrolysis of an ester into an alcohol and acid.

Front 165

Excretory duct

Back 165

Pertaining to excretion; is an interlobular duct draining the intralobular ducts, possessing a pseudostratified or stratified columnar epithelium, and believed to be involved in ionic transport.

Front 166

Exfoliate

Back 166

To shed or eliminate something as of scales from the surface of the body or loss of teeth from the jaws.

Front 167

Exocrine

Back 167

Denotes glands that release their secretary product(s) into a duct system.

Front 168

Exocytosis

Back 168

Discharges of secretary product(s) from the cell, preserving the cell membrane through fusion of the secretary vesicle with the cell membrane.

Front 169

Extracellular matrix

Back 169

Macromolecular products of mesenchymal and epithelial (basement membrane components) cells that provide a role in cellular adhesion. These substrate adhesion molecules are important in induction of epithelia and regulation of cellular migration.

Front 170

Extravasate

Back 170

Fluid that extrudes or escapes from a vessel into the tissues.

Front 171

Fenestrated

Back 171

Perforated with one or more openings.

Front 172

Fertilization

Back 172

Rendering gametes fertile; contact and fusion of spermatozoa and ovum and formation and merging male and female pronuclei and development of zygote.

Front 173

Fibroblasts

Back 173

Elongated, ovoid, spindle-shaped, or flattened cells found in connective tissue that form the connective tissue fibers.

Front 174

Fibronectin

Back 174

An adhesive V-shaped glycoprotein present in the basement membrane that has collagen-binding domains. There is also a heparin-binding domain and a fibrinbinding site on the molecule Fibronectin hinds to integrins called fibronectin receptors on cells. One cellbinding site contains a tripeptide sequence known as the RGD sequence (Arg-Gly-Ash).

Front 175

Fibrous capsule

Back 175

Capsule composed chiefly of fibrous elements.

Front 176

Filamentous bacteria

Back 176

Long, pleomorphic, branched, rod-shaped microorganisms.

Front 177

Filiform papillae

Back 177

The most numerous type of papillae of the dorsum of the tongue. They are threadlike papillae pointing toward the throat.

Front 178

Fissure sealant

Back 178

Composite resin "bonded" directly to the enamel surface that functions to seal out bacteria that cause caries.

Front 179

Fontanelles

Back 179

One of several membranous intervals at the angles of the cranial bones in the infant. Normally there are six, corresponding to the pterion and asterion, on either side, and to the bregma and lambda, in the midline.

Front 180

Fordyce's spots (granules)

Back 180

Ectopic sebaccous glands, located at angles of the mouth.

Front 181

Free gingiva

Back 181

That portion of the gingiva that surrounds the tooth and is not directly attached to the tooth surface; the outer wall of the gingival sulcus.

Front 182

Free pulp stones (denticles)

Back 182

Small calcified masses of dentin that appear as a function of aging or trauma. They develop in the connective tissue of the pulp without obvious relationship to the secondary dentin of the tooth.

Front 183

Frontonasal

Back 183

Region of upper anterior face between the eyes. Nasal placodes arise here.

Front 184

Fungiform papillae

Back 184

One of numerous minute elevations on the dorsum, tip, and sides of the tongue, of a mushroom shape, with the tip being broader than the base.

Front 185

Furcation

Back 185

An anatomic area of a multirooted tooth where the roots divide.

Front 186

G protein

Back 186

Guanosine 5'-triphosphate-binding regulatory protein that alters an intracellular messenger (eg, cyclic nucleotides or CA+ +).

Front 187

Gap junctions

Back 187

Specialized intercellular junctions between cells, with pores permeable to ions and small molecules.

Front 188

Genetic

Back 188

Relating to genetics or ontogenesis.

Front 189

Gingiva

Back 189

That soft tissue surrounding the necks of erupted teeth. It is composed of two parts: the masticatory mucosa facing the oral cavity and the sulcular (crevicula) epithelium and epithelial attachment facing the tooth. The gingiva consists of fibrous tissue, enveloped by mucous membrane, which covers the alveolar processes of the upper and lower jaws.

Front 190

Gingival sulcus

Back 190

The shallow V-shaped trench around each tooth, bounded by the tooth surface on one surface and the epithehal-lined free margin on the other.

Front 191

Glycosaminoglycan (GAG)

Back 191

Noncollagenous macromolecule previously referred to as mucopolysaccharide.

Front 192

Gnarled enamel

Back 192

The enamel located at the tips of the cusps, in which the rods or groups of rods are twisted, bent, and intertwined.

Front 193

Gonial angle

Back 193

Angle between the lower border and posterior ramus of the mandible.

Front 194

Granular layer of Tomes

Back 194

A thin layer of defective dentin adjacent to the cementum, which appears granular and located along the root surface.

Front 195

Granulation tissue

Back 195

The tissue that replaces the blood clot and is formed by new connective tissue and new capillaries.

Front 196

Granulocytes

Back 196

Blood cells that have granules in their cytoplasm. These include neutrophils, eoisinophils, and basophils.

Front 197

Granuloma

Back 197

A nodule of granulation tissue that contain growing fibroblasts and capillaries in response to chronic inflammation.

Front 198

Growth factors

Back 198

Chemical substances that induce cells to initiate DNA synthesis.

Front 199

Gubernacular cord

Back 199

Fibrous cord connecting two structures; a connective tissue band uniting the tooth sac with the alveolar mucosa.

Front 200

Hageman factor

Back 200

The clotting factor XII that becomes activated following injury, and in turn activates the clotting complement kinin and plasmin systems.

Front 201

Hard palate

Back 201

Anterior part of the palate, consisting of the bony palate covered above by the respiratory mucosa of the floor of the nose and below by the ker@ed stratified squamous oral mucosa of the roof of the mouth. The hard palate contains palatine vessels and nerves, adipose tissue, and mucous glands.

Front 202

Haversian bone

Back 202

Compact bone containing tubular channels with blood vessels, nerves, and bone cells with concentrically located lacunae that are termed the Haversian system or osteon.

Front 203

Hemidesmosomes

Back 203

Similar to a desmosome but representing only half of it. @cated on the surface of some epithelial cells and forming the site of attachment between the epithehal cell and the basal lamina. Consist of single attachment plaque, the adjacent plasma membrane, and a related ellular structure that attaches the epithelium to the connective tissue.

Front 204

Hemostasis

Back 204

The process that leads to stoppage of bleeding.

Front 205

Heparan sulfate

Back 205

A glycosaminoglycan consisting of Nacetyl-glucosamine alternating with Dglucuronic acid or D-iduronic acid. When covalendy linked to protein, heparan sulfate proteoglycan is formed.

Front 206

Heterotypic contacts

Back 206

During development these represent the close approximation of epithelium and mesenchyme without an intervening basal lamina.

Front 207

Histamine

Back 207

A vasoactive amine that induces vasoldilation and increases vascular permeability.

Front 208

Hormone

Back 208

Chemical substance formed in one organ or part of the body and carried by the blood to another part where it stimulates or depresses functional activity.

Front 209

Howship lacunae

Back 209

Tiny depressions, pits, or irregular grooves on the surfaces of bones, the result of resorption by osteoclasts.

Front 210

Hunter-Schreger bands

Back 210

Alternating dark and light bands in enamel that result from absorption and reflection of light caused by differences in orientation of adjacent groups of enamel rods originating at the dentinoenamel junction and extending to near the outer enamel surface.

Front 211

Hyalinization

Back 211

A result of compression of the periodontal ligament in which all vasc@ty and most cells are lost from the zone of compression, creating a grasslike appearance. As a result, tooth movement will cease.

Front 212

Hyaluronidase

Back 212

Enzyme that catalyzes the hydrolysis of hyaluronic acid which forms the backbone of proteoglycan molecules in connective tissue.

Front 213

Hydrodynamic

Back 213

Branch of physics that deals with factors determining the flow of liquids. In dentistry, it refers to a theory of pain conduction through dentin.

Front 214

Hypertrophic zone

Back 214

Endochondral cartilage zone characterized by enlargement of existing cells.

Front 215

Hydroxyapatite

Back 215

The inorganic matrix of bone, enamel, cementum, dentin, and cartilage having the chemical formula Ca10(PO4)6(OH)2.

Front 216

Hypomere

Back 216

Portion of the myotome that extends ventrolaterally to form body-wall muscle and is innervated by the primary ventral ramus of a spinal nerve.

Front 217

Hypoxin

Back 217

Refers to low oxygen content of tissues.

Front 218

Iatrogenic

Back 218

An adverse condition resulting from the activities of a health professional.

Front 219

IgA (secretory immunoglobulins)

Back 219

One of the classes of immunogloguhns; the principal immunoglobulin found in exocrine secretions-milk, intestinal and respiratory mucin, saliva, and tears. Antigens entering the oral cavity stimulate IgA synthesis and secretion in the salivary glands to protect the oral mucosa from pathogenic microbes.

Front 220

Immunoglobulins

Back 220

Serum proteins that function as antibodies and are responsible for humoral immunity. There are five classes of immunogloburm: IgG, IgA, IgM, IgD, and IgE.

Front 221

Impaction

Back 221

Position of a tooth in the alveolus so that it is incapable of eruption into the oral cavity. Impaction may be due to crowding of teeth that results in a lack of available space for eruption. Teeth being driven into the alveolar process or surrounding tissues as a result of trauma.

Front 222

Increment

Back 222

The amount by which a given quantity is increased. A measurable amount.

Front 223

Incremental deposition

Back 223

Deposition of material in discrete amounts, rather than constant deposition. Rhythmic recurrent deposition of enamel, bone, dentin, or cementum.

Front 224

Induction, embryonic

Back 224

The act or process of causing the occurrence of a specific morphogenic effect in the developing embryo through the influence of organizers.

Front 225

Innervation

Back 225

Presence and distribution of nerves in a part or the supply of nerve stimulation of a part.

Front 226

Instructive interaction

Back 226

An embryonic interaction between two tissues in which the responding tissue differentiates by receiving specific signals (instructions) from the inducing tissue. The fate of the responding tissue is determined by the tissue with which it interacts.

Front 227

Intercalated duct

Back 227

Intralobular-type salivary gland duct draining the acinus. Intercalated duct cells are cuboidal and contam secretary granules and rough endoplasmic reticulum. They are the smallest ducts within the salivary gland.

Front 228

Interdental septa

Back 228

Bony partitions that project into the alveoli between the teeth; interalveolar.

Front 229

Interglobular dentin

Back 229

A zone of a globular- rather than linear-formed dentin in the crowns of teeth, underlying enamel specifically in the zone separating he mantle and circumpulpal dentin. Characterized by interglobular spaces that are unniinerahzed or hypomineralized dentin between normal calcified dentin layers.

Front 230

Interlobular ducts

Back 230

Ducts of the salivary glands that traverse in connective tissue septa between lobules; also termed excretory ducts.

Front 231

Intertubular dentin

Back 231

That dentin between zones of peritubular dentin that immediately surrounds the tubules.

Front 232

Intralobular duct

Back 232

Ducts within the lobules of the salivary glands of two types: intercalated, lined by low cuboidal epithelium, and striated, lined by tafl cuboidal to columnar epithelium.

Front 233

Intramembranous bone

Back 233

Bone formation within or between connective tissue membranes. It does not replace carfilage, as does endochondral bone.

Front 234

Intratubular dentin

Back 234

The hypermineralized layer of dentin that lies between the sheath of Neuman and the dentinal tubule-

Front 235

Junctional complex

Back 235

Specialized region of contact between adjacent cells; it consists of three regions (moving in order from the apical region of the cell): zonula occludens, zonula adherens, and desmosome.

Front 236

Junctional epithelium

Back 236

Epithelial attachment. That epithelium adhering to the tooth or implant surface at the base of the gingival crevice and consisting of one or several layers of nonkeratinizing cells.

Front 237

Keratinized

Back 237

Having developed a horny layer of flattened cells containing keratin.

Front 238

Keratinized mucosa

Back 238

Stratified surface cornified epithehal cells that lack a nucleus and whose cytoplasm is replaced by large amounts of keratohyalin protein. Keratinized oral epithelium has four cell layers: basal, spinous, granular, and cornified.

Front 239

Keratinocyte

Back 239

Epithelial cells of the mucosa and skin whose main activity is the production of keratin.

Front 240

Lamella

Back 240

Thin leaf or plate as of bone.

Front 241

Lamella enamel

Back 241

Imperfectly calcified thin, leaf-shaped areas of enamel that extend from the outer surface toward the dentin.

Front 242

Lamina dura

Back 242

Radiographic term describing the hard compact bone layer lining the dental alveoli.

Front 243

Lamina propria

Back 243

Layer of connective tissue underlying the epithelium of skin or a mucous membrane.

Front 244

Laminin.

Back 244

A glycoprotein found in the basal lamina. Laminin binds to type IV colllagen; cells, particularly epithelial cells; and neurons through a laminin receptor (integrin) on the cell membrane, and glycosaminoglycans. It is believed to provide a role in Ilular matrix regulation of cell migration and dfferentiation.

Front 245

Langerhans cells

Back 245

Clear or dendritic cells found in both superficial and deep layers of the epidermis and oral epithelium. Contain no desmosomes or tonofilaments. Probably arise from bone marrow and may have immunologic function in recognizing antigenic material.

Front 246

Lateral lamina

Back 246

Band of cells believed to he functionally and structurally similar to the parent dental lamina. Lateral lamina connects the developing tooth germs to the dental lamina.

Front 247

L,eukoplakia

Back 247

Dysfunction of the keratinization process of stratified squamous epithelium resulting in a white appearance of the surface cells.

Front 248

Lingual tonsil

Back 248

Collection of lymphoid follicles on the base, posterior, or pharyngeal portion of the dorsum of the tongue.

Front 249

Lining mucosa

Back 249

Nonkeratinized oral mucosa that covers the cheeks, lips, soft palate, floor of the mouth, and ventral surface of the tongue.

Front 250

Lobe

Back 250

Subdivision of an organ bounded by structural demarcations such as connective tissue septa or fissures.

Front 251

Lobules

Back 251

Small lobes or subdivisions of a lobe that are separated by thin partitions of connective tissue.

Front 252

Lymphokines

Back 252

Cytokines produced by lymphocytes.

Front 253

Macroglossia

Back 253

Enloxgement of the tongue, usually due to local lymphangiectasia or to muscular hypertrophy; megaloglossia.

Front 254

Macrophage

Back 254

Term generally used as a designation for the large mononuclear phagoeytes that are found in various tissues and organs of the body, where they are called histiocytes, "wandering cells," or other terms. They are found in conspicuous numbers in the sinusoids of the spleen, lymph nodes, liver, lungs, and bone marrow. In the brain and spinal cord, they are designated microgha.

Front 255

Major salivary glands

Back 255

The paired parotid, submandibular (submaxillary), and sublingual salivary glands that are responsible for the production of enzyme amylase, mucins, secretary immunoglobulin A (IgA), and other constitutents of saliva.

Front 256

Malassez' epithefid rests

Back 256

Epithelial remnants of Hertwig's sheath in the periodontal ligament. These groups of epithelial cells appear near the surface of the cementum; occasionally they develop into dental cysts.

Front 257

Mandible

Back 257

Horseshoe-shaped bone forming the lower jaw and articulating, by its upturned extremities, the condyles, with the temporal bone on either side- The mandible is composed of the body and the ramus which is located posteriorly. The body includes the alveolar process which contains the teeth.

Front 258

Mannose-6-phosphate (M6P)

Back 258

A marker on lysosomal hydrolases added only to the N-linked ohgosaccharides in the cis-Golgi. M6P binds to M6P receptors that form on the clathrin-coated vesicles and provides the intracellular target signal to direct these enzymes into the lysosomal pathway.

Front 259

Mantle dentin

Back 259

The initially deposited portions of the dentin formed immediately beneath enamel.

Front 260

Marginal leakage

Back 260

Seepage of microorganisms, fluids, and debris along the interface between a dental restoration and the wars of a cavity preparation.

Front 261

Mastication

Back 261

Process of chewing food in preparation for swallowing and digestion.

Front 262

Masticatory mucosa

Back 262

The mucosa that functions in mastication. It tends to be bound to bone and is therefore immovable- It bears forces generated when food is chewed. The mucosa of the hard palate and gingiva.

Front 263

Matrix vesicles

Back 263

Membrane-bounded vesicles that arise by budding and lie free in the extracellular matrix. These vesicles may represent the initial sites of calcification in dentin, bone, and carfilage.

Front 264

Maturation zone

Back 264

Zone of cartilage characterized by chondrocyte enlargement.

Front 265

Maxillia

Back 265

Upper jaw bone; an irregularly shaped bone articulafing with the nasal, lacrimal, zygomatic, palatine, ethmoid, sphenoid, and frontal bones of the face and containing teeth.

Front 266

Maxillary sinus

Back 266

Paired sinus cavifies occupying the space beneath the floor of the orbit and above the roots of the posterior maxillary teeth.

Front 267

Meatus

Back 267

An opening, passageway, or channel.

Front 268

Meckel's cartilage

Back 268

The initial skeletal component of the first bronchial arch. It is the supporting cartilage of the mandibular arch in the embryo.

Front 269

Melanocyte

Back 269

A cell that forms melanin pigment found in the skin and mucous membranes.

Front 270

Membrane performativum

Back 270

Basement membrane separating the enamel organ and the dental papilla preceding dentin formation.

Front 271

Merocrine

Back 271

Type of glandular secretion in which the secreting cells remain intact during the formation and release of the secretary product(s).

Front 272

Mesenchyme

Back 272

Loose undfferentiated embryonic type of connective tissue that usually is of mesodermal origin but that is a mixture of mesodermal and neural crest derivatives in the head and neck region. See Ect4ome-senchy7ne.

Front 273

Mesial drift

Back 273

Gradual movement of a tooth or teeth anteriorly toward the midhne.

Front 274

Mesoderm

Back 274

Mesoblast; the third primary germ layer of the embryo to differentiate. It is positioned between the ectogerm and endoderm.

Front 275

Microglossia

Back 275

Smallness of the tongue.

Front 276

Mineralization front

Back 276

The junction between mineralized and unniineralized tissue-eg, between predentin and denfin, osteoid and bone, or cementoid and cementum.

Front 277

Minor salivary glands

Back 277

The numerous glands located throughout the oral cavity in the lips qabial), cheeks (buccal), hard and soft palate (palatine), tongue (lingual; eg, von Ebner's glands), and glossopalatine.

Front 278

Mixed dentition

Back 278

State of possessing primary and secondary teeth simultaneously.

Front 279

Modulation

Back 279

A reversible change in form and function.

Front 280

Monokines

Back 280

Cytoldnes produced by monocytes.

Front 281

Morphodifferentiation

Back 281

The process which occurs during tooth formation that is responsible for determining the shape of the tootws crown.

Front 282

Morphogenesis

Back 282

The development process that creates the shape and form of an organ. The branching process that occurs during salivary gland development is an example of morphogenesis.

Front 283

Morula

Back 283

Mass of blastomeres resulting from the early cleavage divisions of the zygote.

Front 284

Mucoceles

Back 284

Retention cysts of the minor salivary gland ducts, which contain mucous secretion. Usually the result of rupture of the excretory duct of a minor salivary gland, causing pooling of saliva in the tissues. The resulting versicular elevation is a mucocele.

Front 285

Mucoperiostem

Back 285

A periosteum with a mucous surface. Close combination of mucous membrane (epithelium and lamina propria) with the periosteum of bone to form an apparent single layer.

Front 286

Mucous acinus

Back 286

Minute, saclike secretary portion of a mucous gland. This is the functional unit of the gland.

Front 287

Mucous glands

Back 287

Glands that secrete viscous proteinaceous secretions, such as the sublingual gland; glands of the hard palate.

Front 288

Mumps

Back 288

Parotitis. Enlargement of the parotid gland, an acute contagious viral infection marked by bilateral or unilateral inflammation and swelling and manifested by chills, fever, and headache.

Front 289

Myoepithelial cells

Back 289

Spindle-shaped cells with a stellate body and processes containing darkly staining fibrils found in all the glands of the oral cavity. They are located in the epithelium of the terminal portion of the salivary gland acini and are believed to have contractile ability that facilitates movement of the glandular secretion into the ducts.

Front 290

Myofibrils

Back 290

Fine longitudinal fibrils (parallel with long axis) occurring in a muscle fiber= They are composed of myofliaments.

Front 291

Naris

Back 291

One of the orifices of the nasal cavity; nostril. May be the anterior internal or posterior naris.

Front 292

Nasal region

Back 292

Relating to the area of the nose, subdivided into internal naris, olfactory region, and nasopharynx.

Front 293

Neonatal line

Back 293

Accentuated incremental line or hesitation line seen in hard tissue such as bone, dentin, and deposited enamel. Probably due to metabolic changes occurring at or near the time of birth.

Front 294

Neovascularize

Back 294

To form new blood vessels after an injury.

Front 295

Nerves

Back 295

Whitish cords composed of fibers arranged in bundles (fascicles) and held together by a connective tissue sheath. Nerves transmit stimuli from the central nervous system to the periphery or from the periphery to the central nervous system.

Front 296

Neural crest

Back 296

Ganglionic crest; a band of ectodermal cells that appear along either side of the line of closure of the embryonic neural groove. With the closure of the neural groove to form the neural tube, these bands then he between the developing spinal cord and the superficial ectoderm and later separate into cell groups that constitute the primordia of the ganglia of cranial and spinal nerves. Other derivatives migrate ventrally to induce formation of various other tissues.

Front 297

Neurocranium

Back 297

That part of the skull enclosing the brain, as distinguished from the bones of the face.

Front 298

Nociception

Back 298

The process of responding to pain.

Front 299

Nonkeratinocytes

Back 299

Cells not producing keratin. Clear or dendritic cells found in oral epithelium such as pigment cells (melanocytes), Langerhans cells, Merkel cells, and inflammatory cells such as lymphocytes.

Front 300

Nonkeratinized mucosa

Back 300

Lining mucosa in which the stratified squamous epithehal cells retain their nuclei and cytoplasm. They contain no keratohyalin protein. Lining mucosa is found on the lips, cheeks, soft palate, vestibular fornix, alveolar mucosa, floor of the mouth, and undersurface of the tongue

Front 301

Occlusion

Back 301

Relation of the maxilla and mandibular teeth when in functional contact during activity of the mandible.

Front 302

Odontoblast

Back 302

Layer of columnar cells with processes in the dentinal tubules, lining the peripheral pulp of a tooth. These cells function to form dentin.

Front 303

Odontoblast process

Back 303

Slender protoplasmic process in dentinal tubule. It is a cytoplasmic extension of the cell bodies of the odontoblasts in the dental pulp. They extend from the cell possibly as far as the dentinoenamel junction and the cementoenamel junction.

Front 304

Odontogenesis

Back 304

The entire process of tooth formation, which includes amelogenesis, dentinogenesis, and cementogenesis.

Front 305

Olfactory mucosa

Back 305

Site of most of the receptors for the sense of smell. It occupies the superior aspect of the nasal cavity between the superior nasal conchae, roof of the nose, and upper part of the nasal septum and is composed of ffime cell types: receptor cells, supporting cells, and basal cells.

Front 306

Organic matrix

Back 306

Formative portion of a tooth, as opposed to mineralized hydroxyapatite.

Front 307

Oropharyngeal membrane

Back 307

The embryonic transient membrane portion separating the oral and pharyngeal cavities. It ruptures and disappears during the fourth prenatal week. This membrane is located central to the pharynx and extends from the level of the palate to the vestibule of the larynx.

Front 308

Osmiophilic

Back 308

Tissue components stained easily with osmium or osmic acid.

Front 309

Osseointegmtion

Back 309

A direct structural and functional connection at the light microscopic level between living bone and the surface of a load-carrying implant.

Front 310

Osteoblasts

Back 310

Bone-forming cells derived from mesenchyme. They form the osseous matrix in which they may become enclosed to become osteocytes.

Front 311

Osteoclasts

Back 311

Larger multinucleated cells derived from monocytes with abundant acidophilic cytoplasm, formed in bone marrow and functioning in the absorption and removal of osseous tissue.

Front 312

Osteocytes

Back 312

Cells of the bone located in lacunae, which function in maintenance and vitality of bone.

Front 313

Osteodentin

Back 313

A form of reparative dentin in which cells become trapped in the matrix, giving it a bonelike appearance.

Front 314

Oxytalan fibers

Back 314

Type of connective tissue fiber histochemically distinct from collagen or elastic fibers and found in the periodontal ligament and gingiva. May function in support of blood vessels and principal fibers of the ligament.

Front 315

Palatal rugae

Back 315

Transverse ridges located in the mucous membrane of the anterior part of the hard palate. They extend laterally from the incisive papilla. They have a core of dense connective tissue.

Front 316

Palate, primary

Back 316

That part of the palate formed from the median nasal process. The first palate to form, which is anterior to the secondary palate.

Front 317

Palate, secondary

Back 317

The palate proper, formed by fusion of the lateral palatine processes of the maxilla.

Front 318

Palatine tonsil

Back 318

Faucial; a large oval mass of lymphoid tissue embedded in the lateral wall of the oral pharynx bilaterally located between the p@ of the fauces.

Front 319

Parakeratinized

Back 319

Superficial epithelial cells that have retained their pyknotic nuclei and show some signs of keratinization; the stratum granulosum generally is absent, however.

Front 320

Parenchyma

Back 320

Functional elements of glandular tissue rather than the supporting framework (stroma) of the gland.

Front 321

Parotid

Back 321

The parotid salivary gland located anterior to the ear. It is encapsulated and produces 26% of the secrefions of the major salivary glands.

Front 322

Pellicle

Back 322

Thin skin or film as on the surface of the teeth.

Front 323

Perforating fibers (Sharpey's fibers)

Back 323

Penetrating conneefive tissue fibers by which the tootfs surface is attached to the adjacent alveolar bone. These bundles of collagen fibers penetrate both the cementum and the alveolar bone.

Front 324

Perikymata

Back 324

Wavelike grooves, believed to be the manifestations of the striae of Retzius, on the surface of enamel. They appear transverse to the long axis of the tooth.

Front 325

Periodontal ligament

Back 325

Connective tissue structure that is a mode of attachi-nent of the tooth to the alveolus and consists of collagenous fibers arranged in bundles, between which are loose connective tissue, blood vessels, and nerves.

Front 326

Peritubular dentin (Intratubular dentin)

Back 326

That zone of dentin that forms the wall of the dentinal tubules. This dentin has a 9% higher mineral content than does the remainder of intertubular dentin.

Front 327

Perivascular

Back 327

Ucated around a blood vessel.

Front 328

Permisssive interaction

Back 328

An embryonic interaction between two tissues in which the responding tissue differentiates along a predetermined path. Only the presence of inducing tissue is necessary for differentiation.

Front 329

Phagocytosis

Back 329

The engulfing and digesting of cells, debris, and other substances by cells.

Front 330

Pharyngeal tonsil

Back 330

Third tonsil; Luschka's tonsil; a collection of more or less closely aggregated lymphoid cells located superficially in the posterior wall of the nasopharynx, the hypertrophy of which constitutes the condition called adenoids.

Front 331

Phosphoinositide cycle

Back 331

A signal transduction pathway in which binding to a cell surface receptor activates a G protein that subsequently activates phospholipase C. This enzyme forms two important intermediates from phosphatidyl-inositol-bisphosphate: inositol triphosphate (IP3) and diacylglycerol (DAG). IP3 releases Ca+ + from intracerular compartments, while DAG activates protein kinase C leading to phosphorylation within the cell.

Front 332

Phosphoproteins

Back 332

A conjugated protein in which phosphoric acid is esterified with hydroxyamino acid, usually serine.

Front 333

Phosphophoryn

Back 333

A unique highly phosphorylated protein found in the dentin matrix.

Front 334

Placode

Back 334

A platelike thickening or layer of ectoderm appearing in the embryo.

Front 335

Plaque, dental

Back 335

Deposit of material on the surface of a tooth, which may also serve as a medium for growth of bacteria. May serve as a site for formation of dental calculus.

Front 336

Plasma cells

Back 336

Cells derived from B-lymphocytes, which actively synthesize and secrete antibody (1g) from an extensive rough endoplasmic reticulum. Under appropriate conditions, antigen stimulation induces proliferation and morphologic alterations in B-lymphocytes to form plasma cells.

Front 337

Predentin

Back 337

Organic fibrillar matrix of the circumpulpal dentin matrix before its calcification into dentin.

Front 338

Preeruptive phase

Back 338

Developmental stage preparatory to eruption of teeth and characerized by movements of the growing teeth within the alveolar process.

Front 339

Primary curvatures of the dentinal tubule

Back 339

These are the two curvatures of the dentinal tubule in the crown of the tooth which give the tubule its S shape.

Front 340

Primary intention heafing

Back 340

The healing that occurs when wound edges can be sutured together thereby minimizing scar formation.

Front 341

Proliferative cell zone

Back 341

Zone in endochondral bone formation characterized by the presence of dividing chondrocytes.

Front 342

Proliferative period

Back 342

Time during which cells grow and increase in number by cell division.

Front 343

Proline

Back 343

Naturally occurring nonessential, heterocyclic amino acid.

Front 344

Prostaglandins

Back 344

A group of hormones or hormone-like substances found in semen or menstrual fluid.

Front 345

Proteoglycan (PG)

Back 345

A glycoprotein with a very high content of carbohydrate. These proteins are produced by odontoblasts and fibroblasts, are usually found in younger pulps or during active dentinogenesis, and are found reduced in older pulps.

Front 346

Protein kinase A

Back 346

Cyclic AMP-dependent protein kinase that is the intraccrular effector molecule activated by cyclic AMP

Front 347

Proximate tissue interactions

Back 347

Another term for secondary induction, referring specifically to the requirement that the epithelium and mesenchyme be in close proximity to one another.

Front 348

Pulp bifurcation

Back 348

Zone of branching of the pulp organ, as found in multi-rooted teeth.

Front 349

Pulp organ

Back 349

Soft tissue within the tooth, consisting of connective tissue blood vessels, nerves, and lymphatics.

Front 350

Pulpal blood vessels

Back 350

Characteristic capillary thin-walled blood vessels of the dental pulp. Large vessels in central pulp with loops among odontoblasts.

Front 351

Pulpal stones (denticles)

Back 351

Calcified mass of dentinhke substance located within the pulp or projected into it from its attachment in the dentin wall. (See Attached, Embedded, and Free pulp stones.)

Front 352

Pulp chamber

Back 352

The space surrounded by dentin and in which the pulp organ resides.

Front 353

Pus

Back 353

A wound fluid that is mainly composed of dead neutrophils and their products.

Front 354

Pyknotic

Back 354

A reduction in size, condensation. Usually refers to a cell or nucleus of a degenerating cell in which the chromatin condenses to a structureless mass.

Front 355

Radiation

Back 355

Transmission of rays: light rays, short radiowaves, ultra-violet rays, or x-rays. The latter are used for treatment or diagnosis.

Front 356

Radicular

Back 356

Concerning a root.

Front 357

Ramus

Back 357

General term to designate a smaller structure given off a larger one or into which a larger structure divides.

Front 358

Ramus of mandible

Back 358

Quadrilateral process projecting superiorly and posteriorly from the body of the mandible.

Front 359

Rathke's pouch

Back 359

Ratheke's diverticulum; the pituitary diverticulum. A saclike opening extending from the roof of the stomodeum toward the base of the brain.

Front 360

Red blood cell (corpuscle, erythrocyte)

Back 360

A nonnucleated, biconcave cell bearing hemoglobin and responsible for transport of oxygen to tissues via the circulatory system.

Front 361

Reduced enamel epithelium

Back 361

The several layers of the epithelial enamel organ remaining on the surface of the enamel after enamel formation is complete.

Front 362

Regulated secretion

Back 362

Secretion in a direct response to the binding of a secretagogue to a cell surface receptor, leading to stimulation of a signal transduction pathway (eg, cyclic AMP-G protein or phosphoinositide cycle-calcium) causing secretion. Typically, the secretion product is stored in secretary vesicles and released in response to a secretagogue. There is no secretion in the absence of the secretagogue.

Front 363

Remodeling

Back 363

Altering of the structure by reconstruction. The continuous process of turnover of bone carried out by osteoblasts and osteoclasts.

Front 364

Reparative dentin

Back 364

The deposition of new dentin by newly differentiated odontoblasts at the site of pulpal trauma. A defensive reaction whereby hard tissue formation waus off the pulp from the site of injury.

Front 365

Reserve cell zone

Back 365

Site in endochondral bone characterized by the presence of resting cells termed prechondroblasts. This zone lies adjacent to the perichondrium.

Front 366

Respiratory mucosa

Back 366

Lining of the respiratory system consisting of pseudostratified columnar epithelium containing numerous goblet cells and bearing true cilia in the apical region of the cell.

Front 367

Retzius' striae

Back 367

Lines reflecting successive incremental deposition of mineralized tissue (enamel).

Front 368

Reversal lines

Back 368

Lines separating layers of bone or cementum deposited in a resorption site from the scalloped outline of Howshi@s lacunae. The latter is obliterated by action of osteoblasts or cementoblasts. Deposition of new hard tissue leaving a visible line where the reversal of resorption took place.

Front 369

Root canal

Back 369

The space which contains pulp tissue of the tootws root.

Front 370

Root resorption

Back 370

Dissolution of the root of a tooth by action of osteoclasts. May occur anywhere along the surface of the tooth root in response to caries, trauma, or the loss of primary tooth.

Front 371

Root sheath cells (Hertwig's)

Back 371

Merged outer and inner epithelial layers of the enamel organ, extending beyond the region of the crown to invest the developing root. The cells induce dentinogenesis of the root and atrophy as the root is formed, but when the cells persist, they are called (Malassez') epithelial rests.

Front 372

Root trunk

Back 372

That part of the tooth immediately below the crown neck, covered by cementum and fixed in the alveolus.

Front 373

Sagittal plane

Back 373

Median plane in the anterior-posterior direction.

Front 374

Saliva

Back 374

Clear, slightly e, somewhat viscid mixture of secretions of the salivary glands and 04val fluid exudate. It functions to moisten the mucous membranes and food, facilitating speech and mastication. Contains water and 0.58% solids.

Front 375

Salivary calculi

Back 375

Calcium phosphate concretions (salivary stones) found within a salivary gland or duct, most commonly in the main excretory duct of the submandibular gland (Whartoifs duct); the pathological state known as sialolithiasis.

Front 376

Salivary corpuscle

Back 376

One of the leukocytes or lymphocytes found in saliva.

Front 377

Salivary gland

Back 377

Exocrine glands whose secretions flow into the oral cavity.

Front 378

Sclerotic dentin

Back 378

Dentin in which tubules are occluded with mineral. This dentin then is nontubular and is termed transparent. Occurs mostly in elderly people, especially in the roots of teeth.

Front 379

Sealant, dental

Back 379

Agent that protects this enamel surface against the access of saliva. A resin capable of bonding to the surface of a tooth and offering protection against outside chemical or physical agents.

Front 380

Secondary curvatures of the dentinal tubule

Back 380

These are microscopic undulations of the dentinal tubule formed during deposition and mineralization of the dentin matrix.

Front 381

Secondary dentin deposition

Back 381

Deposition of dentin circumpulpally formed after tooth eruption.

Front 382

Secondary induction

Back 382

Embryonic induction other than the primary neural induction, which involves the interaction of epithelium and mesenchyme that occurs in the teeth and salivary glands. In induction one cell population (A) responds to a second group of cells (B), which causes a change in phenotype of the fu-st population (A) to form a new cell type (C). The newly differentiated cells (C) will only form if the inducer (B) is present. After differentiation these cells may serve as inducers when they are proximate to other cells.

Front 383

Secondary intention healing

Back 383

The healing that occurs when wound edges cannot be approximated, which causes healing with significant scar formation.

Front 384

Secretagogue

Back 384

Signal in extracellular environment that stimulates the release of secretary product within the regulated pathway. O-Adrenergic and muscarinic drugs are secretagogues for salivary gland acinar cells.

Front 385

Secretory canaliculus (Secretory capillary)

Back 385

Canaliculus found between acinar cells. Spaces provide communication between the serous acinar cells and the lumen. They rarely are found between mucous cells.

Front 386

Secretory granules

Back 386

A prominent feature of the secretary cell accumulating in its apical cytoplasm. Granules are about 1 um in diameter and have a distinct, limiting membrane and a dense homogenous content.

Front 387

Senescence

Back 387

The state of growing old; beginning old age.

Front 388

Serotonin

Back 388

A vasoconstrictor found in serum and body tissues that has the ability to modify neuronal function.

Front 389

Serous

Back 389

Relating to, containing, or producing a serious substance that has a watery consistency.

Front 390

Serous demilumes

Back 390

Half-moon or crescent-shaped serous cells associated with the terminal external surface of mucous alveoli.

Front 391

Serous glands of tongue (von Ebner)

Back 391

Serous glands opening in the bottom of the trough surrounding the circumvallate papillae and functioning in cleansing action.

Front 392

Sheath of Neuman

Back 392

Boundary between the intratubular and peritubular dentin. It represents the initial boundary of the dentinal tubule prior to intratubular dentin deposition.

Front 393

Sialography

Back 393

Diagnostic x-ray technique visualizing salivary gland ducts by injection of a radiopaque substance into the main excretory duct.

Front 394

Short-range matrix-mediated interaction

Back 394

An embryonic interaction that is mediated by inductive molecules within the extracellular matrix, the matrix itself, or paracrine factors liberated in the immediate area.

Front 395

Sinusoid

Back 395

Resembles a sinus, a cavity. A form of terminal blood channel.

Front 396

Sjogren's syndrome

Back 396

Disease often associated with rheumatoid arthritis and believed to be an autoimmune disorder. Lymphoid infiltration of the parotid, submandibular, labial, and palatal glands leads to atrophy of gland parenchyma, which results in exocrine gland dysfunction.

Front 397

Smear or smear layer

Back 397

Debris formed by instrumentafion of the tooth. The debris or smear particles form a layer that occludes dentinal tubules.

Front 398

Soft palate

Back 398

The posterior muscular portion of the palate, forming an incomplete septum between the nasopharynx and the oral cavity.

Front 399

Somatic growth

Back 399

The growth pattern of the body in general.

Front 400

Specialized mucosa

Back 400

Mucosa found on the dorsum of the tongue that consists of four types of papillae: filiform, fungiform, circumvallate, and foliate-

Front 401

Squamosal

Back 401

Relating to the flat squama, as of the temporal bone.

Front 402

Squamous epithelium

Back 402

Composed of a single layer of flat scalelike cells, as in the lining of the pulmonary alveoli; oral epithelium.

Front 403

Stapedial artery

Back 403

Artery that supplies the region of the middle ear (stapes). Important in prenatal facial development.

Front 404

Stellate reticulum

Back 404

A network of star-shaped cells in the center of the enamel organ between the outer and the inner enamel epithelium.

Front 405

Stomodeum

Back 405

The future oral cavity of the embryo; an invagination lined by ectoderm.

Front 406

Stratified epithelium

Back 406

A type of epithelium composed of a series of layers. The cells of each may vary in size and shape, as seen in skin and some mucous membranes.

Front 407

Stratum germinativum

Back 407

The inner layers of the epidermis resting on the corium; consists of several layers of polygonal cells (stratum spinosum) and a basal layer.

Front 408

Stratum intermedium

Back 408

That epithelial cell layer of the enamel organ which lies external and adjacent to the inner enamel epithelium and is attached to it by desmosomes. Stratum intermedium also refers to the intermediate layer of nonkeratinizing epithelia.

Front 409

Striated duct

Back 409

An intralobular salivary gland duct involved in ionic transport, located between the intercalated and interlobular ducts, and named for the basal striations produced by infoldings of the basal membrane that produce compartments containing numerous mitochondria.

Front 410

Stroma

Back 410

Supporting framework of a gland, such as the capsule and trabeculae, rather than the functional parenchyma.

Front 411

Sublingual

Back 411

Area beneath the tongue, subglossal.

Front 412

Sublingual gland

Back 412

The smallest of the three pairs of major salivary glands. A pure mucous gland located in the anterior floor of the mouth.

Front 413

Submandibular

Back 413

Area beneath the lower jaw.

Front 414

Submandibular gland

Back 414

Largest of the three paired major salivary glands contributing 65% of saliva. These two bilateral glands are a mixed seromucous type.

Front 415

Submucosa

Back 415

Layer of tissues that lies beneath the lamina propria underlying the mucous membrane of the lip, cheek, palate, and floor of the mouth.

Front 416

Successional lamina

Back 416

That portion of the dental lamina which is lingual to the developing deciduous teeth. It gives rise to the enamel organs that differentiate into permanent teeth.

Front 417

Supporting bone

Back 417

Bone tissue functionally related to the roots of the teeth. It surrounds, protects, and supports the tooth roots through the alveolar bone proper.

Front 418

Sympathomimetics

Back 418

Imitating the effects of postganglionic adrenergic nerves.

Front 419

Synarthrosis

Back 419

A suture between two bones, with the uniting medium being a fibrous membrane continuous with the periosteum.

Front 420

Synchondrosis

Back 420

A type of cartilaginous joint that usually is temporary. The intervening hyaline cartilage ordinarily converts to bone before the person reaches adult life.

Front 421

Syndesmosis

Back 421

A type of fibrous joint in which opposing surfaces are united by fibrous connective tissue, as in the union between most of the facial bones.

Front 422

Synovial cells

Back 422

Cells that secrete synovial fluid. These are of two types: A and B. Type A is thought to secrete hyaluronic acid, while type B produces a protein-rich secretion.

Front 423

Synovial membranes

Back 423

Membranes that line joint cavities and function to secrete a small amount of clear transparent alkaline fluid in the articular spaces. Synovial fluid acts as a lubricant and nutrient for the avascular tissue covering (ie, the condyle and articular tubercle of the temporomandibular joint). Also called synovial fluid.

Front 424

Taste bud

Back 424

Receptor of taste in the oropharynx. One of a number of goblet-shaped cells oriented at right angles to the surface by the epithelium. They consist of supporting cells and gustatory cells.

Front 425

Temporomandibular joint

Back 425

Joint formed between the condyle of the mandible and the mandibular fossa (concavity of the temporal bone).

Front 426

Temporomandibular ligaments

Back 426

Four ligaments: on the medial surface, the sphenomandibular; on the posterior surface, the stylomandibular; on the lateral surface, the temporomandibular and capsular.

Front 427

Tenascin

Back 427

An extracellular matrix molecule, transiently expressed during development, that slightly resembles fibronectin. It interacts with fibronectin in the extracellular matrix to regulate cell adhesiveness, an important environmental factor in cell migration and tissue remodeling during development.

Front 428

Teratogen

Back 428

Agent or factor that causes the production of physical defects in the developing embryo.

Front 429

Terminal bar apparatus

Back 429

That part of the ameloblast that separates Tomes' process from the cell proper; localized condensations of cytoplasmic substance associated with the cell membrane.

Front 430

Tic douloureux

Back 430

Trigeminal neuralgia, repeated contraction, spasm, or twitching of the masticatory muscles usually resulting in extreme pain.

Front 431

Tight junction

Back 431

Fusions of the outer portions of adjacent cell membranes believed to provide a seal and communication between cells.

Front 432

Tomes' granular layer

Back 432

A granular-appearing layer in the dentin of the root adjacent to the cementum.

Front 433

Tomes' process

Back 433

Specialized apical zone of the ameloblasts. The apical Tomes' process is conical and interdigitates with the forming enamel rods.

Front 434

Tonofibrils

Back 434

Systems of fibers found in the cytoplasm of epithelial cells, which function with the desmosomal plaque to hold adjacent cells together.

Front 435

Tooth crypt

Back 435

Space filled by the dental follicle and developing tooth in the alveolar process.

Front 436

Traction bands of the palate

Back 436

Bundles of collagen that firmly attach the oral mucosa to the underlying bone of the hard palate.

Front 437

Transduction

Back 437

Conversion of physical force into biologic response. Theory proposing that odontoblasts are sensory receptors for pain stimuli transmitted through the dentin.

Front 438

Transport vesicles

Back 438

Vehicles for the transport of materials from the intracellular compartment to another compartment (eg, from the rough endoplasmic reticulum to the Golgi apparatus).

Front 439

Trimer

Back 439

A molecule composed of three identical, simpler molecules.

Front 440

Tufts

Back 440

Clump or cluster of organic filled spaces in enamel that extends fi-om the dentinoenamel junction for one third of the thickness of enamel. Results in a defect in mineralization.

Front 441

Turnover

Back 441

Quantity of a material metabolized or processed in the body or a tissue within a given length of time.

Front 442

Types I and III collagen

Back 442

Two of the fibrillar collagens that form collagen fibrils after secretion into the extracellular milieu. Type I collagen is the most prominent form, accounting for about 90% of the collagen in the body. It is found in bone, tendon, and sldn. Type HI col4en is found in loose connective tissue, blood vessels, and in hematopoietic and lymphoid tissues, and is associated with the connective tissue side of the basement membrane.

Front 443

Type IV collagen

Back 443

The type of collagen associated with the basement membrane.

Front 444

Vasculature

Back 444

Reference to the blood vessels and circulating blood system.

Front 445

Vermillion zone (border) of the lip

Back 445

Transitional zone between the skin of the lip and the mucous membrane of the hp known as the red zone- Color due to thin epithelium, the presence of eleiden in the cells, and superficial blood vessels apparent in humans.

Front 446

Vestibular

Back 446

Lip furrow band labial and buccal to the dental lamina; forms the oral vestibule between the alveolar portions of the jaws and the lips and checks.

Front 447

Vicerocranial

Back 447

Those parts of the facial cranial skeleton that are of bronchial arch origin.

Front 448

Vomer

Back 448

Flat unpaired bone located in the midhne of the face, shaped like a trapezoid, and forming the inferior and posterior portion of the nasal septum. It articulates with the sphenoid, ethmoid, two maxillary, and two palatine bones.

Front 449

Waldeyer's ring

Back 449

Group or ring of tonsilar tissue at the oral-pharyngeal-nasal junction.

Front 450

Zona pellucida

Back 450

Translucent zone, noncellular secreted layer, surrounding an ovum. It has a striated appearance due to the numerous fme canals with which it is pierced.

Front 451

Zonula adherens (intermediate junction)

Back 451

Part of the junctional complex of columnar epithelial cells located deep to the zonula occludens where the plasma membranes of two adjacent cells divert to form a 15-nm- to 20-nm-wide space.

Front 452

Zonula occludens (tight junction)

Back 452

Part of the junctional complex immediately beneath the free surface and continuing all around the perimeter of the cell. There is no intercellular space, and the zonula occludens provides a permeability barrier to lumenal material.

Front 453

Zymogen

Back 453

An inactive precursor that is activated to an enzyme by the action of an acid and an enzyme. Granules in serous cells of enzyme-secreting glands, such as the salivary glands and the pancreas.