we have face the problem that what we do read before 1 day of viva....?

1. What is....?- 1
What is ……? Answers
Accessory canals During root formation, when there is a premature loss of root sheath cells
or when the developing root encounter a blood vessels an opening or a
connection is established between the radicular pulp and the periapical
connective tissues. Such a connection is referred as accessory canals.
These are common in apical third of the posterior teeth.
Acellular cementum The cementum, common in the apical third of root, which does not
consist of cementocytes is called as acellular cementum
Acid phosphatase It is an enzyme associated with hard tissue destruction and mainly
localized to the lysosomes of the osteoclasts. They are more commonly
exhibited by an active cell in areas of hard tissue destruction.
Acinus It is the terminal secretory end piece of any gland where the active
ingredients of the secretions are synthesized and released.
Active eruption It is the process or the movement of a normal tooth from its place of
formation in the jaw bones to its place of function along the occlusal
plane is called as active eruption.
Adherence junctions Found below tight junctions and show a visible gap between adjacent cell
membranes. No structures are found in this gap. The cellular side of
adherens junctions contains a fine matting of fibrous material
(microfilaments) which are embedded in dense plaques composed of
myosin, tropomyosin, alpha-actinin, and vinculin.
Alkaline phosphatase It is an enzyme associated with hard tissue formation or mineralization.
They are capable of hydrolyzing phosphoric acid esters. Hence these
enzymes readily supply the much required phosphate ion at the site of
mineralization.
Alveolar bone That part of jawbones provides the support for the teeth.
Alveolar bone fundus Base of the alveolar socket
Alveolar bone proper A thin lamella of bone that surrounds the root of the tooth and gives
attachment to the principal fibers of the periodontal ligament is the
alveolar bone proper.
Alveolar bone,
supporting
The part of the alveolar bone that surrounds the alveolar bone proper and
gives supports to the socket is the supporting alveolar bone.
Alveolar crest It is the thin margin of the bone that surrounds the teeth
Alveolar crest fibers It is one of the principal periodontal fibers that radiate from the crest of
the alveolar process to the cervical part of the cementum.
Alveolus It is that part of jawbones in which the teeth are embedded.
Amelin It is an enamel protein constituting about 5 to 10% of all enamel proteins.
They play a role in crystal growth.
Ameloblasts The enamel forming cells derived from ectoderm, which differentiates
from the inner enamel epithelium of the enamel organ.
Amelogenesis The process of formation of enamel is called as amelogenesis
Amelogenins Of all the enamel proteins, 90% of them belonged to a heterogeneous
group of gene- specific, low molecular low weight proteins called as
Amelogenins.
Amylase Enzymes present in saliva those catalyses the hydrolysis of starch in to
smaller water soluble carbohydrates. Also known as salivary amylase
Anatomic repair When a damaged root surface is repaired by the reestablishing the former

2. out line by cementum formation it is called as anatomic repair
Anatomical crown The part of the crown that extends from the occlusal or incisal surface to
the cervical line is the anatomical crown.
Anchoring fibrils These Type VII collagen fibrils are found in the basement membrane and
provide a mechanical attachment for the epithelium with the underlying
connective tissue.
Annexins Calcium binding proteins that interact with acid phospholipids in
membranes. Examples are lipocortins, endonexins.
Apatite crystals The inorganic constituent of any biological mineralized tissue is a
calcium phosphate salt approximating in to a crystal structure referred as
the apaite or hydroxyapatite crystals.
Apical cementum Cementum deposited on the apical region of the root.
Apical fibers It is one of the principal periodontal fibers that radiate from the apex of
the teeth to the alveolus.
Apical foramen The radicular pulp is continuous with periapical connective tissues
through a small opening at the tip or the apex called as the apical foramen
Apposition It is the process of deposition of the matrix of the hard dental tissues
Aquaporin Group of homologous integral membrane water channel proteins
expressed in fluid transporting epithelia. Modulate the osmolority of
fluids in salivary glands.
Articular disk It is an extension of the fibrous capsule of the tempromandibular joint in
to the joint cavity dividing the joint in to 2 compartments – the upper and
lower compartments. It provides an articular surface for the head of the
condyle.
Articular eminence It is the prominence of the temporal bone anterior to the
tempromandibular joint.
Attached Gingiva The part of the gingiva that firmly attaches to alveolar process.
Basal lamina It is the electron microscopic appearance of the basement membrane that
separates the epithelium and the underlying connective tissue. It consists
of three layers – two layers of lamina densa separated by a lamina lucida
and the anchoring fibrils below.
Basal layer The layer of the epithelium that is closest to the connective tissue. It
provides the epithelial stem cells as well as cells to supplement the
epithelial differentiation.
Basement membrane It is the light microscopic appearance of the basal lamina. It appears as a
thin demarcation separating the epithelium and connective tissues. It
answers positive with a magenta color with PAS reagent staining.
Bone Morphogenetic
Proteins
Transforming growth factor- beta group of proteins; Can induce
bone/cartilage formation; Plays a vital role in tooth formation
Bone Morphogenic
protein
These are a heterogeneous group of proteins that are responsible for the
proper initiation, formation, development, maturation and calcification of
hard tissues.
Bone sialoprotein These are a heterogeneous group of non-collagenous proteins that are
responsible for the proper calcification of hard tissues. They probably
function as a nucleator of calcification.
Buccopharyngeal
membrane
This membrane separates the stomatodeum from the primitive pharynx
(cranial part of the foregut). This membrane ruptures at 24 to 26 days and
communication with the amniotic cavity is established.
Bud stage Initial stage of tooth development; gives rise to enamel organ

3. Bundle bone The part of the alveolar bone proper, which has the bundles of the
principal fibers of periodontal ligament, continues in to this bone as
Sharpey’s fibers.
Burtonian line Lead and bismuth in high quantities produce exogenous pigmentation
along the gingival margins as bluish black-to-black lines called as
Burtonian lines. The color is due to the formation of metallic sulphide,
the sulphide radical derived from the bacterial sources.
Cadehrins It is a calcium dependent transmembrane protein that helps in the
attachment of cells to the extracellular matrix. They belong to the integrin
family of proteins.
Calciotraumatic line A type of incremental line of dentin separating secondary and reparative
dentin
Calcospherites The globular zones of mineralization in any hard tissues are referred as
calcospherites.
calculus, dental Hard calcified plaque.
Calvaraia Skull cup
Cambium layer The osteogenic cellular layer of the periosteum in a sutural bone is
referred as the cambium layer. They play a vital role in the growth of the
sutural bones.
cAMP or Cyclic AMP Second or intracellular messenger of target cells.
Canaliculi, Bone Small microscopic space that have cellular projection of osteocytes
Canaliculi,
Cementum
Small microscopic space that have cellular projection of cementocytes
Canaliculi, Dental Space occupied by branches of dentinal tubule
Cancellous bone A network of bony trabeculae called as the cancellous or spongy bone
interrupts the bone marrow cavity.
Cartilage Calcified connective tissue characterized by non-vascularity and firm in
consistency. three types - hyalin, fibroelastic, elastic
Cell Differentiation An increase in morphologic/chemical heterogeneity
Cell free zone This is a layer found in the pulp just adjacent to the odontoblastic layer
and is a space in which the odontoblast move pulp ward during new
dentin formation.
Cell proliferation Developmental process in which cell undergoes cell cycle dividing in to
two daughter cells, leading to increase in number of cells
Cell rests. Malassez Epithelium remnants of root sheath in periodontal ligament
Cell rich zone This is a layer of pulp below the cell rich zone. It is made up of numerous
fibroblasts, collagen, fibers, undifferentiated mesenchymal cells and
inflammatory cells
Cellular cementum The cementum, common in the apical third of root, which consists of
cementocytes is called as cellular cementum
Cementicles Calcified spherical cemental bodies, free/ attached or embedded
Cementoblasts The cementum forming cells derived from the ectomesenchymal dental
sac cells.
Cementocytes The cementoblasts that get entrapped in the cementum it forms and is a
resting cell is called as cementocytes.
Cementodentinal
junction
The relatively smooth surface where dentin and cementum meets is
separated by a type of cementum called as the intermediate type of
cementum.
Cementoenamel The relationship of cementum and enamel at the cervical region is called

4. junction as the cementoenamel junction. The cementum overlaps enamel (60%) or
meet at sharp point(30%) or does not meet at all(10%).
Cementoid tissue The uncalcified matrix of cementum is called as cementoid tissue
Cementum The ectomesenchymal derived mineralized dental tissue that covers the
anatomical roots of a human tooth.
Cervical line The junction of the cementum and enamel is marked by a demarcating
line called cervical line
cervical loop Growing free border of enamel organ. The outer& inner enamel epithelial
layers continously divided deeper and lead to formation of root.
Cervical loop See epithelial diaphragm
Choanae Paired openings between nasal cavity and nasopharynx.
Chondrocranium embryonic skull before ossiifcation; Cartilageonous skull
Cingulum Lingual lobe of anterior teeth
Circular collagen
fibers
This is a small group of the gingival fibers that form a band around the
neck of the tooth, interlacing with other group of fibers in the free gingiva
and helping free gingiva to bind to the tooth.
Circumpulpal dentin It is that part of primary dentin that encircles the pulp chamber and does
not include the mantle dentin
Circumvallate
papillae
Adjacent and anterior to the sulcus terminalis there are about 8 to 12 large
papillary structures surrounded by a deep circular groove where the
minor serous salivary glands (of von Ebner) are located along with taste
buds.
Clinical crown The part of the anatomical crown that is visible in the oral cavity is called
as the clinical crown.
Col The interdental gingiva has an outline of a depression with the buccal and
lingual interdental papilla at the ends. This depression is just below the
contact point and is called as the col.
Collagen White fibers of the connective tissue, composed of fibers, fibrils and
interfibrillar cement
Collagen Collagens are the major heterogenous group of fibrous proteins found in
the extracellular matrix
Compact bone Hard, external calcified cancellous portion of bone
Contour lines of
Owen
These contour lines results from incremental daily deposition of dentin
along the secondary curvatures of dentinal tubules.
Coronal pulp The pulp in the crown of teeth
Cribriform Bone containing perforation/foramina
Cribriform plate The bone lining the tooth socket, the bundle bone, is perforated by many
foramina that transmits nerves and vessels and hence called as the
cribriform plate.
Crown, anatomical The portion of crown that is from cervical line to cusp/incisal ridge
crown, Clinical The portion of crown that is visible in the oral cavity
Crypts Pit like depressions
Cuff epithelium During eruption, the cells of outer layers of reduced enamel epithelium
and the basal layers of oral epithelium proliferate to form a mass of
epithelium. The teeth emerge through the selective apoptosis of this
epithelium and this epithelium plays a role in establishment of the
primary epithelial attachment of teeth to the periodontal tissues.
Cusp Is an elevation on the crown portion making up a occlusal part
Cytodifferentiation The process by which an undifferentiated cell attains more differentiation

5. phenotype
Cytoskeleton Each cell needs a internal framework to provide support, facilitate
intracellular transport and permit motility called the cytoskeleton. This
cytoskeleton is made up of microtubules and filaments.
Dead tracts They are the dentinal tubules where the odontoblastic process has
disintegrated due to noxious stimuli and subsequently filled with air.
They appear black in transmitted light and white in reflected light under
dried ground section.
Decorin One of an important proteoglycan found in association with collagen
fibrils as “decorations” and regulates the growth of the collagen fibrils.
Demilune Crescent shaped serous cells in a mixed gland that has a cap over the
ends of a mucous acinar cells.
Demilunes In a mixed salivary gland the tubular mucous salivary acini is often
capped by a resent shaped seromucous cells called as the demilune that
discharge their contents in to the tubular end piee.
Dental lamina Horseshoe shaped epithelial bands that transverse the upper& lower jaw
and give rise to ectodermal portion of tooth
Dental Papilla formative organ of dentin and pulp
Dental papilla Dental papilla is the ectomesenchymal tissue condensations that
immediately sub adjacent to the enamel organ and gives rise to the dentin
and pulp.
Dental sac Is the sac like ectomesenchymal thickening surrounding the enamel
organ and dental papilla. In latter stages, it gives rise to the fibrous
attachment apparatus of the teeth and cementum.
Dentary bones These are the lower jawbones of the lower vertebrates that bear the tooth.
Denticles These are the discrete calcified masses found in the pulp tissue. These are
concentric layers of mineralized tissues formed by surface accretion
around a thrombi, dying or dead cell or around a collagen fiber. They may
be free (free denticles) or attached to dentin (attached denticle). If the
calcified masses may resemble the dentin (true denticles) or remain as a
structureless calcified mass (false denticles).
Dentin The ectomesenchymal derived mineralized dental tissue that forms the
bulk of the crown and root and lies beneath the enamel in anatomical
crown and cementum in anatomical root in a human tooth.
Dentin
Phosphoprotein
See Phosphoryn
Dentin Sialoprotein A phosphorylated, highly glycosylated protein with high amounts of
sialic acid
Dentinal fluid The fluid that is found within the dentinal tubules is known as the
dentinal fluid
Dentinal lymph See dentinal fluid
Dentinoenamel
junction
It is a hypocalcified structure representing the junction of the dentin and
enamel, which is scalloped to facilitate increased surface area of contact.
Dentinogenesis The process of formation of dentin by the odontoblasts is called as
dentinogenesis.
Dentogingival
collagen fibers
These are one of the major groups of gingival fibers that extend from the
cervical cementum in to the lamina propria. It is the most numerous
group of gingival fibers.
Dentoperiosteal group
of fibers
These are one of the major groups of gingival fibers that extends from the
cervical cementum in to the periosteum of the alveolar crest, vestibular

6. surface and oral surface of the alveolar bone.
Desmoplakin The attachment plaque made of protein found only in desmosomes is the
desmoplakin.
Desmosomes A junction in which adjacent cell membranes are visibly separated and
filled with dense fibrous material. An electron dense layer lines the
cytoplasmic face of desmosomes in which are embedded an abundance of
fibers made up of the proteins described above for zonula adherens
junctions as well as intermediate filaments such as keratin.
Developmental
grooves
Shallow grooves that separate cusps or primary parts of teeth
Dichophase The stage of cell division of a basal epithelial cell when it decides to
either differentiate or divide is called as the dichophase.
Differentiation Growth associated with distinguishing character/function from adjacent
structures from original type/specialization
Diffuse calcifications This is a structure formed as a result of regressive change of pulp where
there is a calcification in the pulp that appear as irregular calcification
deposits in the pulp tissues.
Diphyodont Two sets of teeth
Ducts The tubular elements of the exocrine glands that forms a pathway through
which the secretions are taken to the site where the secretion is
discharged.
Dystrophy Disorder arising from defective or faulty nutrition
Ectochondral Bone Type of bone formation within cartilage and replacing it
Enamel The ectodermal derived mineralized dental tissue covers the anatomical
crown of a human tooth.
Enamel cord Epithelial proliferation that seems to divide the dental organ in two.
Enamel Knot Collection of epithelial cells associated with inner enamel epithelium of
the enamel organ. A transient structure responsible for producing
signaling molecules.
Enamel knot Thickening of the internal dental epithelium at the center of the dental
organ. `
Enamel lamellae These are thin leaf like hypocalcified structures seen in enamel arising in
planes of tension. They arise from the enamel surface extending towards
the dentinoenamel junction.
Enamel niche It is an artifact that is produced during section of the tissue. It occurs
because the dental organ is a sheet of proliferating cells rather than a
single strand. It looks like a concavity that contains ectomesenchyme.
Enamel organ Are small knob like structure arising from dental lamina that represents
initiation of teeth development and gives rise to the enamel
Enamel rod Each enamel rod has a cylinder-like shape and is composed of crystals
that run parallel to the longitudinal axis of the rod. At the periphery of the
rod, the crystals flare laterally.
Enamel spindles These are extension of the odontoblastic process extending in to the
enamel.
Enamel tufts They are the grass like appearing hypocalcified structures of enamel
arising at dentinoenamel junction and extending till one third of enamel
thickness. They probably appear due to abrupt change in direction of
enamel rods at the dentinoenamel junction.
Enamelcord A structure connecting enamel knot to enamel niche

7. Enamelin An acidic glycosylated phosphoprotein of mature enamel.
Entactin An extracellular matix glycoprotein associated with basal lamina
Epithelial diaphragm Hertwig’s epithelial root sheath bend at the future cementoenamel
junction in to a horizontal plane.
Epithelium Cellular, avascular layer covering all the free surface of the body -
internal/external & lining of vessels.
Epithelium, inner
enamel
The cells that line the concavity of the enamel organ in the cap/early bell
and differentiates in to ameloblast to give rise to enamel
Epithelium, Outer
enamel
Cuboidal peripheral cells of the cap/bell stage of tooth development that
lines the convexity of the cap
Eruptive tooth
movements
The tooth movements that accompany a tooth bud when it moves its
place of formation to its place of function is called as the eruptive tooth
movements.
Extracellular Matrix Macromolecular products of mesenchymal and epithelial (rarely, as in
basement membrane components) cells that provide a role in cellular
adhesion
Extrinsic fibers of
cementum
The collagen fibers embedded in the cementum that arises by the
incorporation of the periodontal ligament fibers.
False dentin This is a structure formed as a result of regressive change of pulp where
there is a calcification in the pulp with the structure not resembling
dentin.
Fibrils The subunits of fibers. Each fibril is formed by packing of individual
molecules. For example, tropocollagen molecules condense to form
collagen fibril.
Fibronectins Are protein molecules associated with fibroblast. They polymerize to
form pericellular matrices and mediate binding of one connective tissue
cell, especially fibroblast to others. Plays a major role in eruption of teeth
& associated with periodontal traction theory.
Fibronexus The connection between the Sharpey’s fibers and fibroblast, cemented by
a protein called fibronectin. The area of this cementation is refereed as
fibronexus. Also found in many other situations in connective tissue,
especially where two cells is adhered through the fibronectin.
Filiform papillae On the anterior, dorsal part of the tongue, there are numerous, fine
pointed cone shaped epithelial structures with a core of connective tissue
that gives the tongue velvet like appearance and lacks taste buds.
Foliate papillae In the posterior lateral surface of tongue, sharp parallel clefts, contains
the foliate papilla which contains taste buds. It is said to be a vestigial
organ.
Fontanelles One of several membranous intervals at the angles of cranial bones in an
infant. there are six fontanelles - corresponding to pterion, asterion (on
both side) as bregma and lambda in the midline
Fossa Depression or concavity in any surface of crown
Free nerve endings Sensory receptor for pain
Functional repair When a damaged root surface is repaired by the reestablishing the former
out line by bone formation that fits in to the damaged area it is called as
functional repair.
Fungiform papillae In the anterior dorsal surface of tongue, interspersed between the filiform
papillae are isolated, fungi like appearing, reddish prominences with one
to three taste buds.
Furcation An anatomic multi-rooted tooth where the roots divide

8. G protein Guanosine 5-triphosphate binding regulatory protein that alters an
intracellular messenger
Gap junctions Junctions in which direct cell-cell communication can occur through
small pore structures called connexons. As an example, heart muscle
contraction is coordinated in part through cell-cell communication across
gap junctions.
Gingiva The soft tissue covering the root, alveolar bone extending from
dentogingival junction to the alveolar mucosa.
Gingival sulcus Or the Gingival crevice is the space between the inner aspect of the
gingival and the tooth.
Glands of von Ebner The minor serous salivary gland situated in the trough of the circumvalate
papillae.
Glycosaminoglycans Glycosaminoglycans are polymers of repeating disaccharide units
constructed of hexosamine and carboxylate or sulfate ester.
Gnarled enamel Optical phenomenon produced by abrupt changes in rod direction and
twisting of rods around each other over the cusps of teeth.
Gomphosis The type of joint between 2 calcified structures through a soft tissue
Gubernacular canals In the coronal part of the developing permanent teeth (except molars) in
the alveolar crypt, bone surrounds the tooth germ along with a small
canal, the gubernacular canal and filled with remnants of dental lamina
and connective tissue, forming the gubernacular cords. This cords is
believed to guide the permanent tooth as it erupts.
Gubernacular cords In the coronal part of the developing permanent teeth (except molars) in
the alveolar crypt, bone surrounds the tooth germ along with a small
canal, the gubernacular canal and filled with remnants of dental lamina
and connective tissue, forming the gubernacular cords. This cords is
believed to guide the permanent tooth as it erupts.
Haversian canal A part of functional and basic metabolic unit of bone, the osteon. The
concentric circumferential lamellae has a central vascular canal called
the Haversian Canal
Hemidesmosomes A special type of desmosomal junction occurring between basal
epithelial cells to the underlying extracellular matrix
Hertwig’s epithelial
root sheath
The fusion of the inner and outer enamel epithelium after completion of
enamel secretion produces this layer that is responsible for the
development of root
Heterogenous
mineralization
The process of mineralization which does not occur uniformly throughout
the tissue
Heterogenous
nucleation
The process of mineralization where the seeding or initiation of
mineralization does not occur uniformly throughout the tissue.
Histodifferentiation A process by which cells undergoes definitive morphologic as well as
functional changes and acquire their functional assignment accompanied
by loss of ability to multiply.
Homogenous
nucleation
The process of mineralization which occur uniformly throughout the
tissue
Horizontal collagen
fibers
A type of periodontal fibers that run horizontally from the cementum to
the alveolar bone. Mostly found in the center part of the root
Howship’s lacunae The area of resorption associated with the osteoclast in bone is irregular
with a scalloped outline called Howship’s lacunae.
Hunter -Schreger
bands
These are alternating dark and light bands of varying width, best seen in
longitudinal sections. They appear due to the change in direction of rods

9. and is considered to be a functional adaptation
Hyaline layer of
Hopewell smith
Along the Cementodentinal Junction in apical third of posterior tooth, a
small band that neither appears to be cementum or dentin and is structure
less, called the hyaline layer or the Intermediate cementum
Imbrication Fine Striations in the dentin; Also called as Striae of Von Ebner
Incal cartilage A part of the Meckel’s cartilage that persists to form the Incus.
Inner enamel
epithelium
The tall columnar cells that line the concave surface of the cap stage of
tooth development. It undergoes histodifferentiation to become
ameloblasts and secretes enamel.
Integrins A group of cell surface proteins that mediate the binding of cells to
extracellular matrix proteins to one another.
Intercalated ducts The single layered structures made of a low cuboid cells found between
the salivary secretor units that conduit saliva but also contribute to
macromolecular components.
Interglobular dentin Zones of hypomineralization between the globules of calcification in
dentin
Interlobular Duct Channels located outside lobes of salivary glands
Intermediate
cementum
Along the Cementodentinal Junction in apical third of posterior tooth, a
small band that neither appears to be cementum or dentin and is structure
less, called the hyaline layer or the Intermediate cementum
Interradicular
collagen fiber
The group of periodontal fiber that runs between the two roots
Intertubular dentin It is that part of the dentin that lies between the dentinal tubules and is the
main body of dentin
Intralobular duct Channels locatyed within lobes of salivary glands
Intramembranous
bone growth
The direct formation of bone within highly vascularized sheets of
condensed primitive mesenchyme.
Intratubular dentin The dentin that immediately surrounds the dentinal tubules. As the
deposition of dentinal tubules occurs in the inner wall of the tubule, it is
preferred term. Also known as the peritubular dentin.
Intrinsic fibers of
cementum
The collagen fibers embedded in the cementum that arises from the
cementoblastic activity.
Irregular secondary
dentin
See tertiary dentin
Junctional epithelium Junction of the tooth and gingival epithelium. The union between this
epithelium and tooth is the epithelial attachment
Keratinization The total sum of changes in metabolical, morphological and biochemical
changes that occurs when the cells of mucosa moves from basal layer to
the superior most layer is called as keratinization
Keratinocytes The cells that undergo the keratinization
Keratins The product of Keratinization,
Keratohyaline
granules
In the stratum granulosum in the keratinized mucosa contains small
organelle that are highly hematxophillic and secrete the keratin. They are
also called as Keratinosome, Odland bodies, membrane coating granules.
Krause end bulbs Sensory receptor for cold
Krause’s bulb Fine nerve endings associated with pressure/tactile sensation
Kroff’s fibers These are argyrophilic ground substances. Earlier they were thought to be
collagen fibers formed among odontoblasts.
Lamellae of bone The sequence of concentric or parallel deposition that forms the bulk of

10. bone
Lamellate granules Lamellar granules found in stratum granulosum discharge their contents
in to intercellular space forming a permeability barrier.
Lamina densa An electron microscopic feature of Basement membrane, Basal Lamina,
it is the dense portion that is found in the basal lamina
Lamina dura The thin radiopaque line in the intraoral oral periapical radiographs of the
tooth, which indicates the bundle bone surrounding the tooth just next to
the cementum.
Lamina limitans It is the inner organic lining of the calcified dentinal tubule wall.
Lamina lucida An electron microscopic structure in basal lamina indicating a electron
rare region between lamina densa and the anchoring fibrils
Lamina propria The connective tissue component of oral mucosa
Lamina splendens The fibrous layer covering condyle is lined by a vascular fibrous
connective tissue
Laminins They are the group of extracellular glycoproteins involved several vital
functions including communication, defense and attachment. Produced in
general by epithelial cells. Major constituent of basal lamina, interacts
with type IV collagen
Langerhan’s cell The dendritic, non-keratinocyte, high level clear cell of the oral mucosa
that is an antigen presenting cells. A major player in immune system
Lectins Groups of cell surface proteins.
Lining mucosa The mucosa that lines the oral cavity
Loricrin Sulphur rich component of the keratohyaline granules
Macula adherens See adherence junctions
Macula occludens See tight junctions
Malassez, cell rests Remnants of the Epithelial Hertiwgs Sheath
Mantle dentin The outermost layer of primary dentin formed by the newly
differentiated odontoblast and lacks phosphophoryn.
Marginal Ridge Ridge or elevation of enamel forming the margin of the surface of a
tooth; specifically, mesial &distal of occlusal surfaces posterior teeth &
mesial /distal margins of lingual surfaces anterior teeth
Masticatory mucosa The type of mucosa that is exposed to stress and strain of mastication. It
is the mucosa that covers the palate, alveolar mucosa.
Meckel's cartilage It is the 1st branchial arch cartilage. It does not form the mandible but
indicates the position of the future mandible.
Meissners corpuscles Sensory receptor for touch
Melanin An endogenous pigment
Melanocyte The melanin producing cells, a non-keratinocyte in epithelium and a low
level clear cell
Melanophage The macrophages that accumulate the melanin when there is a spill of
melanin
Melanosomes Melanin produced by melnocyte are transferred through their dentritic
process to basal keratinocyte that stores in the form of melanosomess
Membrana
preformitiva
The basement membrane that separates the enamel organ and dental
papilla just prior to dentin formation
Membrane
Preformativum
Basement membrane separating enamel organ and dental papilla
preceeding dentin formation.
Merocrine Type of glandular secretion in which secreting cells remains intact during
formation and relase of secretory products

11. Metalloproteinases The group of enzymes those are associated with the breakdown of
connective tissue fibers and matrix. These enzymes break down the
ground substance, matrix as well as fibers so remodeling can occurs
Microfibrils Smaller units of fibrils
MorphodifferentiationA process by which the ameloblasts establish the basic form and relative
size of teeth by differential growth
Mucopolysaccharides previously known as Glycosaminoglycans
Muscularis Mucosae Intervening layer of smooth muscles and elastic fibers between lamina
propria and submuosa in intestinal mucosa
Nasmyth’s membrane It is a delicate membrane that covers the newly erupted crown of the
teeth and rapidly removed due to mastication. It is believed to be
basement membrane in origin.
Neonatal line or ring An accentuated incremental line seen in the enamel and dentin of the
deciduous teeth between the hard tissues that is formed before and after
birth due to abrupt change in environment and nutrition
Neural fold
Neural groove
Neural plate
Neural tube
Neuropores
Appearance of the notochord and prechordal mesoderm induces the
overlying ectoderm to thicken and form the neural plate. Cells of the
plate make up the neuroectoderm and their induction represents the
initial event in the process of neurulation. Once neural induction has
occurred, the elongated, slipper-shaped neural plates expand toward the
primitive streak. By the end of the third week, the lateral edges of the
neural plate become more elevated to form neural folds, and the
depressed midregion forms the neural groove. Gradually, the neural
folds approach each other in the midline, where they fuse. This fusion
begins in the cervical region (fifth somite) and proceeds cranially and
caudally. As a result, the neural tube is formed. Until fusion is complete,
the cephalic and caudal ends of the neural tube communicate with the
amniotic cavity by way of the cranial and caudal neuropores,
respectively.
Nidogen also called entactin is a rod-shaped protein consisting of a single
polypeptide chain. Nidogen binds with high affinity to collagen IV and
laminin, it has an organ izing role in assembly of the basal lamina.
Nidogen also binds perlecan, the large heparan sulfate proteoglycan of
the basal lamina. The coexpression of laminin 1 and nidogen results in a
relatively stable basal lamina. Laminin is produced by epithelial cells and
nidogen is secreated by mesenchymal cells.
Non-keratinocytes The non-epithelial cells found in the layers of stratified squamous surface
epithelium
Oblique collagen
fibers
The group of periodontal and gingival fibers that run obliquely
Oblique Ridge The ridge that extends from the mesiopalatal cusp to the distobuccal cusp
as seen in permanent maxillary first molars
Odontoblastic processThe cytoplasmic extension of the odontoblasts
Odontoblasts The dentin forming cells derived from the ectomesenchymal dental
papilla cells.
Odontoclasts The cells responsible for removal of calcified parts of the tooth
Olfactory bulbs Sensory organelles responsible for olfaction, ie sense of smell
Oncocytes These cells are associated with salivary glands. They are strongly
eosinophilic because of their very high concentration of rnitochondria.
They are present in small numbers in secretory endpieces and ducts.

12. Oncocytes increase in number with age.
Oropharyngeal
membrane
See buccopharyngeal membrane
Orthokeratinization Loss of nucleus in process of keratinization in the superficial cells
Osteoblasts The bone forming cells
Osteoclasts The bone resorbing cells
Osteocytes The osteoblasts that are entrapped in its own matrix. They are viable and
is said to be a resting osteoblasts
Osteodentin When the cells forming the tertiary dentin is trapped with in it, it is
referred as osteodentin
Osteogenesis Formation of bone
Osteoid The newly secreted bone matrix that is not calcified
Outer enamel
epithelium
The peripheral cells of the enamel organ in the cap and bell stage that are
cuboidal and lie in the convexity or the outer surface of the teeth surface.
Parakeratinization Presence of pynknotic nucleus and remnants in the process of
keratinization in superficial cells
Parietal layer of
nerves
See plexus of Rashkow
Pellicle It is a membrane formed on the surface of enamel by the precipitate of
the salivary proteins. When colonized by microorganism it is becomes the
pathological plaque.
Perikymata These are transverse wave like grooves on the surface of enamel and
believed to be the external manifestation of striae of Retzius
Peritubular dentin It is that part of the dentin that immediately surrounds the dentinal
tubules.
Perivascular cells The cells that are found in vincity of vascular channels
Permanent dentition The dentition that replaces the primary dentition
Pharyngeal tonsil Lymphoid aggregation in the posterior wall of nasopharynx. Also known
as Luschka's tonsil or third tonsil.
Phosphoryn A highly phosphorylated protein found in dentinal matrix
Pit Small pinpoint depression found in fossa
Plaque A complex microbiological ecosystem formed by the accumulation and
colonization of oral microbes of the salivary pellicle
Plexus of Rashkow In the pulp, there is a network of peripheral axons of nerves adjacent to
cell rich zone. This layer is called as the plexus of Rashkow.
Predentin The recently secreted or formed dentin is located adjacent to the pulp
tissue and is not mineralized.
Prickle cell layer See stratum spinosum
Primary cementum The cementum formed in the teeth before it reaches its place of its
function
Primary curvature of
dentin
This is the S shaped course of the dentinal tubules formed due to the
overcrowding of the odontoblasts as they retreat pulpally.
Primary dentin It is the dentin that is formed before root formation is completed. It
makes the bulk of the dentin and outlines the pulp chamber.
Primary enamel
cuticle
See Nasmyth’s membrane
Prisms, enamel See Enamel rod, alternate name
Procollagen The newly secreted collagen molecule that needs to undergo post-
transitional modification to become collagen

13. Procollagen peptidaseThe enzyme that are involved in modifying procollagen to collagen
Procollagenase Serves as a part of the major pathway for activation of matrix
metalloproteinases that helps in remodeling of connective tissue.
Prostromelysin and procollagenase are secreted as inactive forms that are
proteolitically activated by plasmin. Plasmin is generated from
plasminogen by the action of plasminogen activator (PA). Urokinase PA,
associated with the cell surface, activates matrix metalloproteinases in the
immediate vicinity of the cell. Tissue
Proteoglycans Glycosaminoglycan chains link covalently with core proteins to form
proteoglycans.
Pulp The ectomesenchymal derived soft tissues made up of odontoblasts,
fibroblasts, collagen, fibers, undifferentiated mesenchymal cells and
inflammatory cells. It occupies the innermost portion of the human teeth.
Pulp canal It is the space occupied by the pulp in the root
Pulp chamber It is the space occupied by the pulp in the crown
Pulp horn The thin extension of pulp towards the superficial occlusal/incisal part of
the tooth
Pulp space The space occupied by pulp
Pulp stones The calcified masses present in the pulp.
Pulp stones, Attached The type of pulp stones attached to the dentinal walls.
Pulp stones,
embedded
Small calcified masses of dentin that protrude from dentin in to pulp.
Also known as embedded pulp stones
Radicular pulp The pulp found in the root of teeth
Reactive dentin See tertiary dentin
Reciprocal induction The phenomenon by which the cell signals of the epithelium and
primitive ectomesenchyme mutually initiate and regulate the formation
and differentiation of specialized structures such as enamel, dentin and
cementum
Reduced enamel
epithelium
Post-functional, by the collapse of the stratum intermedium and stellate
reticulum, the ameloblast and the outer enamel epithelium combine to
form the reduced enamel epithelium that would serve to protect the newly
formed enamel. A part of the reduced enamel epithelium forms the future
junctional epithelium
Reichert's cartilage It is the 2nd branchial arch cartilage, which forms the stapes, styloid
process, and superior hyoid bone.
Remodeling The phenomena by which the old bone is removed and new bone is
deposited.
Reparative dentin See tertiary dentin
Resting lines The regular line that denotes the period of rest during formation of bones.
Rests of Malassez The epithelial remnants of Hertwig’s epithelial root sheath usually in the
gingiva and periodontal ligament fibers
Retepegs They are the finger like projection of the epithelium in to the lamina
propria
Reteridges They are the finger like projection of the connective tissue in to the
epithelium
Reticulin A basement membrane protein
Reversal lines The basophilc cement line with little or no collagen & high in
glycoprotiens and proteoglycans that marks the limit of bone erosion
prior to formation of osteon is the reversal libe

14. Rhombomeres Much of the face is derived from neural crest cells that migrate into the
pharyngeal arches from the edges of the cranial neural folds. In the
hindbrain, crest cells originate from segmented regions known as
rhombomeres. There are eight of these segments in the hindbrain (R1 to
R8), and crest cells from specific segments populate specific arches.
Crest cells from R1 and R2 migrate to the first arch, cells from R4 go to
the second arch, those from R6 and 7 to the third arch, and those from R8
to the fourth and sixth arches. In addition, the first arch receives crest
cells originating in the midbrain. Few if any crest cells form from R3 and
R5. Most of the cells from these rhombomeres undergo cell death by
apoptosis, while a few migrate with crest cells originating from adjacent
segments.
Ridge Linear elevation on any surface of tooth named for their location
Ruffini’s corpuscles Principal Sensory mechanoreceptors
Saliva The secretion of salivary gland
Salivary calculi The calcification of the plaque that is observed in clinically exposed area
of the oral cavity. Also called as supragingival calculus
Salivary pellicle It is the deposition of the complex polysaccharides, proteins and
glycoproteins of saliva over the tooth surface along with the food debris
Sclerotic dentin Mild chronic stimuli induce collagen fibers and apatite crystals formation
in dentinal tubules occluding it. As the refractive index becomes
equalized, it turns transparent and this event is common in older
individuals.
Secondary cementum The cementum formed in the teeth after it reaches its place of its function
Secondary curvature
of dentin
Smaller oscillations in the primary curvature of dentin is reffered as the
secondary curvature of dentin tubules
Secondary dentin It is the dentin that is formed after the root formation has been completed.
Secondary dentition The second set of teeth that follows the primary dentition.
Secondary
physiologic dentin
The dentin that is formed after the completion of crown.
Serous glands The glands whose secretion is thin and watery
Sharpey’s fibers The projection of collagen fibers in to the cementum is called as
Sharpey’s fibers.
Specialized mucosa The type of mucosa that has been evolved to undertake a specific
function. For example tongue for taste perception.
Spongy bone Cancellous bone that has a honeycomb appearance with large marrow
cavities and sheets of trabecular bones
Squames Fully cornified dead cells that are formed in the epidermis, hard palate,
and oral gingival epithelium
Statherins A salivary protein responsible for remineralization of enamel
Stellate reticulum The polygonal cells beneath the outer enamel epithelium with higher
concentration of intercellular fluid and albumin. Seen only in cap and bell
stage of tooth development.
Stomatodeum Refers to the primitive mouth that appears as a small depression in the
early embryo
Stratum basale The inner most layer of the stratified epithelium. Has got tall columnar
cells that can divide or differentiate to form the mucsoa
Stratum corneum The outer most layer of the stratified epithelium. Rich in keratin.
Stratum distendum The layer in the non keratinized epithelium that is also referred as

15. “stratum distendum” is the startum superficial as it lacks filligrin.
Stratum
germinativum
The other name for stratum Basale and parabasal spinous cell layer.
Stratum granulosum The layer of stratified epithelium just above the prickle cell layer or the
stratum spinosum. Contains cells that are larger and flater. Contain large
number of basophilic keratohyaline granules and nucleus shows evidence
of degeneration and pyknosis.
Stratum intermedium A layer formed during bell stage of teeth development between inner
enamel epithelium and stellate reticulum with high degree of metabolic
activity.
Stratum lucidum A layer of mucosa in skin.
Stratum spinosum The layer of stratified epithelium just above the stratum basale. Made up
of irregular polyhedral committed to differentiation epithelial cells. Also
known as prickle cell layer
Stratum superficiale The layer of stratified epithelium at the top or the outer most layer of
epithelium from the connective tissue. Imparts rigidity as well as the first
line of protection
Striae of Retzius These represent the incremental pattern or the successive apposition of
layers of enamel during crown formation.
Striae of von Ebner See Imbrication Lines
Striated ducts The ducts that connect the intercalated ducts and the excretory ducts.
Largest portion of this system and made up of tall columnar epithelium
with large amount of mitochondria
Stromelysin It is a matrix metalloproteinase III. Stromelysins attack proteoglycans,
elastin, fibronectin, laminin , and collagen types IV, V, IX, and X.
Submucosa The layer that is found just below the mucosa
Successional lamina The lingual extension of the dental lamina from which permanent
dentition arises. Develops from fifth month in vitro to tenth month of age
Sulcular epithelium The non-keratinized epithelium that lines the sulcus of the gingival
crevice
Sulcus Long depression seen in teeth
Sulcus terminalis The separation between the anterior two third and posterior third is
marked by a V shaped depression, just anterior to foramen caecum. This
is the Sulcus terminalis
Synarthrosis Sutures between two bones united through a fibrous membrane that is
continous with the perisoteum
Synchondrosis A type of temporary cartilaginous joint. The intervening hyaline cartilage
is replaced by bone by adult life.
Syndecan Syndecans are integral membrane proteoglycans. Syndecans are not only
matrix receptors but also co-receptors for growth factors and cytokines,
capable of potentiating signal transduction events.
Syndesmosis Fibrous joint in which opposing surfaces are united by fibrous connective
tissues.
Synovial fluid The fluid in the joint space
Taste buds Small, ovoid or barrel shaped intraepithelial organs associated with
valate, foliate, fungiform papillae in tongue and certain other parts of oral
cavity and oropharynx. They are associated with perception of taste
through a highly specialized central and local mechanism.
Tenascin Tenascin, a large extracellular matrix molecule, also known as cytotactin

16. and hexabrachion, is made up of six polypeptide chains assembled to
form a sixarm structure capable of interacting with a variety f cells and
extracellular matrix molecules. They bind to cell surface proteoglycan -
Syndecan
Teratology It is the study of developmental defects caused by adverse factors in the
environment
Tertiary dentin It is a dentin that is produced in reaction to noxious stimuli after the root
formation is completed.
Tight junctions A junction where adjacent cell membranes appear to be cemented or
fused together. Sometimes fused areas are broken by non-fused regions.
These junctions form a tight seal around the apical portion of cells,
forming a water-tight barrier. These junctions are also involved in
maintaining membrane, allowing specializations, compartmentalization
of the apical and basal membranes.
Tome’s layer The sudden bending of the dentinal tubules, coalescing and looping of
dentinal tubules nearer the cement-enamel junction in the apical third of
roots.
Tome’s process It is the projection of the ameloblasts in to the newly secreted enamel
matrix during amelogenesis.
Tomes granular layer A granular appearing layer in the root dentin caused by the coalescing
and looping of the terminal portions of the dentinal tubules
Tonofibrils Small filaments of keratin bundled together, together with desmosomes
forms the intercellular bridges in light microscopy.
Tonofilaments Keartin filaments bundled together
Trabecular bone Irregular Network like appearance.
Transduction The type of sensory conduction perceived by odontoblastic process
through subtle changes in dentinal lymph
Transeptal fiber
system
The fibers of periodontium that runs across the alveolar septum especially
in posterior multi-rooted teeth
Transit time The time between the formation and secretion of collagen molecule
Transparent dentin See sclerotic dentin
Transverse Ridge Union of 2 triangular ridges that cross the posterior surface of a tooth
Triangular Ridges Main ridges on each cusp that run from the tip of the cusp to the central
part of the occlusal surface
True denticles This is a structure formed as a result of regressive change of pulp where
there is a calcification in the pulp with the structure resembling dentin.
Tubercle Small elevation of enamel on the crown
Tublin A protein that is found in odontobalstic process and is an intracellular
protein of microtubules
Tuftelin A non amelogenin protein of enamel and a nucleator for enamel
crystaliization. The enamel layer adjacent to dentinoenamel junction is
heavily mineralized as soon as it is formed is due to the presence of:
Vermillion zone The junction of oral mucosa and skin in lips is the vermillion.
Vestibular lamina Is an epithelial thickening arising labial and buccal to the dental lamina
that hallows out and forms the vestibule.
Vimentin The intermediate filament type found in connective tissue cells
Vinculin A peripheral cytoplasmic protein that interacts with integrin through
Talin. Conformational changes in Vinculin cause it bind to actin iand
completing the cell’s contractile elements with fibronectin in

17. Extracellular matrix
Volkman canals The connection between adjacent Havesian’s canal in osteon containing
blood vessels.
Von Kroff’s fibers The larger diameter collagen fibers with an extreme affinity for silver
stain, composed mainly of type III collagen and found in the mantle
dentin, adjoining the Dentinoenamel junction
Weil’s zone See cell free zone
Woven bone First formed bone with irregularly oriented collagen fibers of varying
diameters.
Zona occludentes See tight junctions
Zonula adherens See adherence junctions