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Histology Exam 4
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312
Other
Not Applicable
07/15/2008

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Term
Label the crown, cementoenamel junction, root and apex of this diagram.
Definition
[image]
Term
mineralized/calcified
Definition
the hard tissues of the tooth are called hard because they are _____.
Term
a. ectoderm
b. ectomesenchyme
Definition
What two embryonic tissues are necessary to form a tooth?
Term
1. bud
2. cap
3. bell
4. crown
5. root
Definition
Name the 5 stages of tooth development in the correct order.
Term
histodifferentiation
Definition
the functional stage of tooth development that occurs when ameloblasts, odontoblasts and cementoblasts form is called ____.
Term
primary teeth
Definition
- 1st teeth present in mouth
- btwn 6 months and 6 years of age
Term
6 months and 6 years
Definition
Between ___ months and ___ years, all teeth are primary teeth.
Term
permanent
Definition
- second set of teeth present in mouth
- just after 12 years
Term
12 years
Definition
After ___ years, all teeth in the mouth will be permanent.
Term
anatomical crown
Definition
- portion of tooth covered by enamel
Term
clinical crown
Definition
- part of enamel that can be seen in the mouth above the gums
Term
cervix
Definition
- junction of the crown with the root
Term
cervix
Definition
- cementum joins the enamel at the ____ of the tooth
Term
- CEJ or cervical line
Definition
- the point at which the cementum and the enamel join
Term
root
Definition
- embedded in alveolar bone and is covered by cementum
Term
furcation
Definition
- point of branching roots
Term
apex
Definition
- tip of each root
Term
periodontium/periodontal attachment apparatus
Definition
- tissues that surround the tooth
- function to attach tooth root to surrounding alveolar bone
Term
periodontium/periodontal attachment apparatus
Definition
- consists of cementum, periodontal ligament, alveolar bone and gingiva
Term
hard tissues
Definition
- mineralized or calcified
Term
hard tissues
Definition
- enamel
- dentin
- cementum
- alveolar bone
Term
soft tissues
Definition
- do not have mineral or calcification
Term
soft tissues
Definition
- pulp
- periodontal ligament
- gingiva
Term
odontogenesis
Definition
- tooth development or tooth morphogenesis
Term
True
Definition
T/F: If the hard and soft tissues do not form during the correct stages of fetal development, they will not form at all.
Term
False, they are the same but develop at different times
Definition
T/F: The process for odontogenesis is different for primary and permanent teeth, but they develop at different times.
Term
embryonic period
Definition
primary teeth begin to form during the ____ period of development.
Term
fetal period
Definition
permanent teeth begin to form during the ___ period of development.
Term
False. Tooth development continues for many years after birth.
Definition
T/F: Tooth development stops after birth.
Term
True!
Definition
T/F: The teeth have the longest developmental time for any organ in the body.
Term
two types of tissues
Definition
Odontogenesis requires ___ type(s) of tissue(s).
Term
False. You MUST have both types of tissues
Definition
T/F: You can have one or the other of the different types of embyronic tissue for tooth formation.
Term
ectoderm
Definition
- forms oral epithelium
Term
oral epithelium
Definition
- forms dental lamina
Term
ectomesenchyme
Definition
mesenchyme and cranial neural crest cells become ___.
Term
dental lamina
Definition
- interacts with ectomesenchyme to form tooth germs
Term
tooth germs
Definition
- formed when dental lamina interacts with ectomesenchyme
Term
20 tooth germs. 10/arch
Definition
By the 8th week of embyronic development there should be ___ tooth germs for primary teeth. ___ in the maxillary arch and ___ in the mandibular.
Term
1. bud stage
2. cap stage
3. bell stage
4. crown stage
5. root formation
Definition
Name the 5 morphological stages of tooth development.
Term
bud stage
Definition
- 1st stage of development that can be recognized by morphology
Term
bud stage
Definition
- tooth germ appears either as round mass or column of dental lamina surrounded by ectomesenchymal cells
Term
bud stage
Definition
- stage where ectomesenchymal cells and dental lamina are proliferating
Term
column of dental lamina surrounded by ectomesenchymal cells
Definition
The bud stage tooth appears as round mass or column of ____ surrounded by ____.
Term
cap stage
Definition
- stage where cells of dental lamina proliferate and form enamel organ
Term
dental papilla
Definition
During the cap stage, the ectomesenchyme beneath the enamel organ is called ___.
Term
cap stage
Definition
- stage where ectomesenchyme under enamel organ is called dental papilla.
Term
dental sac or dental follicle
Definition
Ectomesenchyme surrounding the enamel organ is called ____ or ____.
Term
enamel organ
Definition
- derives from ectoderm
Term
enamel organ
Definition
- forms enamel of tooth crown
Term
enamel organ
Definition
- protects enamel before tooth erupts so that cementum does not form on top
Term
enamel knot
Definition
- cluster of cells in center of enamel organ
- may be biological mechanism to shape crown of tooth
Term
dental papilla
Definition
____ is ectomesenchyme.
Term
closest to the enamel organ
Definition
cells of dental papilla _____ the enamel organ differentiate into odontoblasts
Term
odontoblasts
Definition
- secrete dentin
Term
inner cell mass
Definition
Which part of the dental papilla forms the pulp?
Term
dental sac/follicle
Definition
- some cells will become cementocytes
- other cells will form periodontal ligament
Term
cementocytes
Definition
- produce cementum
Term
cells of dental sac/follicle that form periodontal ligament
Definition
- contribute to alveolar bone formation
Term
bell stage
Definition
- stage where enamel organ has a deeply invaginated concave side where the dental papilla is located.
Term
dental papilla
Definition
During the bell stage, the enamel organ has a deeply invaginated concave side where ____ is located.
Term
1. outer enamel epithelium
2. stellate reticulum
3. statum intermedium
4. inner enamel epithelium
Definition
Which 4 cell layers are present in the enamel organ at the bell stage?
Term
ameloblasts
Definition
inner enamel epithelium differentiates into _____.
Term
inner enamel epithelium
Definition
- single layer of cells that faces dental papilla
Term
bell stage
Definition
The dental lamina breaks up during the ____ stage of odontogenesis.
Term
rests of Serres
Definition
- epithelial cell islands formed when dental lamina joins the tooth germ to the oral epithelium
- usually disintegrates but can lead to cysts
Term
crown stage
Definition
During ____ stage, dentin and enamel are formed and the shape of the crown is established.
Term
dentin
Definition
- forms first in the crown
Term
enamel
Definition
- forms second in the crown
Term
crown stage
Definition
some of the dental papilla cells become odontoblasts in this stage.
Term
odontoblasts
Definition
- secrete crown pre-dentin then mineralize to form crown dentin
Term
ameloblasts
Definition
- secrete enamel matrix and mineralizes it to enamel
Term
basal lamina/basement membrane
Definition
the _____ between odontoblasts and ameloblasts become the DEJ.
Term
cervical loop
Definition
- histological and structural part of enamel organ
- junction where inner enamel epithelium meets the outer enamel epithelium of the enamel organ
Term
cervical loop
Definition
- site where HERS will form from inner and outer enamel epithelium
Term
Hertwig's epithelial root sheath
Definition
HERS
Term
cervical loop
Definition
- will become cervix of tooth as adult
Term
root formation
Definition
Stage where HERS forms the tooth root.
Term
False. Root development starts after crown is completely shaped
Definition
T/F: Root development starts before crown is completely shaped and as tooth is erupting.
Term
HERS
Definition
- determines number, shape and length of roots
Term
root formation
Definition
- continues even after tooth erupts
- takes many years to complete
Term
HERS
Definition
- directs formation of odontoblasts from dental papilla cells during the root formation stage
- directs formation of cementoblasts from dental sacs/follicles
- some become epithelial rests of Malassez
Term
odontoblasts
Definition
- make root pre-dentin then mineralize to form root dentin
Term
cementoblasts
Definition
- make pre-cementum then mineralize to form cementum
Term
initiation
Definition
- beginning of tooth development
Term
proliferation
Definition
- dental lamina and ectomesenchyme increases in size because of mitosis of cells
Term
morphodifferentiation
Definition
- folding of enamel organ determines shape of tooth crown and number of cusps
Term
histodifferentiation
Definition
- cells in enamel organ become ameloblasts
- cells in dental papilla become odontoblasts
- cells in dental follicles become cementoblasts
Term
apposition
Definition
- incremental growth of mineralized tissues by the successive addition of dentin and enamel to growing tooth crown
Term
successional dental lamina
Definition
- forms toot germs for succedaneous permanent teeth
Term
succedaneous permanent teeth
Definition
- permanent tooth with primary tooth before it
Term
lingual
Definition
successional dental lamina forms ____ to primary tooth germ.
Term
accessional or non-succedaneous teeth
Definition
- permanent teeth with no primary teeth before
Term
permanent molars
Definition
- develop from posterior extension of dental lamina distal to primary 2nd molar
Term
dentin
Definition
- 1st mineralized tissue of tooth to form
Term
crown and root
Definition
dentin is found in the ___ and the ___.
Term
bulk of the tooth
Definition
dentin forms the ____ of the tooth.
Term
dentinogenesis
Definition
- formation of dentin
Term
crown dentin, root dentin
Definition
___ dentin is always formed first follows by ____ dentin.
Term
odontoblasts
Definition
- cells that form dentin
Term
dental papilla cells
Definition
odontoblasts differentiate from _____ cells.
Term
basement membrane
Definition
there is a ______ between dental papilla cells and inner enamel epithelium that becomes DEJ.
Term
pre-dentin
Definition
odontoblasts first secrete layer of matrix called ____.
Term
pre-dentin
Definition
- contains all organic material of dentin, mainly collagen type 1
- does not contain mineral
- avascular
Term
collagen type I
Definition
- organic fibrillar/fibrous matrix
Term
pre-dentin
Definition
____ is mineralized to form dentin.
Term
calcium phosphate aka HAP
Definition
- mineral component of dentin
Term
HAP aka calcium phosphate
Definition
- inorganic material of dentin
Term
70%
Definition
___ % HAP in fully mineralized dentin
Term
incisal/cuspal edge --> apical direction
Definition
during crown formation, dentin is formed first at the ___ edge of tooth and continues in an ___ direction.
Term
cervix --> apical direction
Definition
during root formation, dentin forms first at ____ and continues in ____ direction.
Term
the tooth is vital
Definition
dentin continues to be formed as long as _____.
Term
odontoblasts
Definition
___ migrate towards the pulp as they deposit dentin.
Term
pulp
Definition
odontoblasts migrate towards the ____ as they deposit dentin.
Term
cell bodies
Definition
odontoblast _____ will eventually be found in the pulp at the pulp-dentin interface.
Term
pulp-dentin interface
Definition
- odontoblast cell bodies found here
Term
pre-dentin
Definition
there is always a layer of ____ next to pulp.
Term
odontoblastic process
Definition
- portion of odontoblast left in dentin
Term
cell process
Definition
- cell cytoplasm but not nucleus
Term
dentinal tubules
Definition
- channels of dentin
- contain odontoblastic processes
- extend through dentin from pulp to DEJ or DCJ
Term
components of dentinal tubules
Definition
- odontoblastic process
- dentinal fluid
- axons
- unmineralized collage type I
Term
dentinal tubules
Definition
- gives dentin it's permeability/porosity
- may allow bacteria into pulp
- provide resilience/elastic quality to prevent enamel fractures
Term
dentin classification based on developmental pattern
Definition
- primary
- secondary
- tertiary
Term
dentin classification based on location
Definition
- mantle dentin
- circumpulpal dentin
- intertubular dentin
- intratubular/paratubular dentin
Term
dentin classification based on mineral content
Definition
- sclerotic dentin
- globular dentin
- interglobular dentin
Term
primary dentin
Definition
- dentin based on developmental pattern
- formed during odontogenesis, before completion of apical foramen of root
- ends when root is completely formed
- majority of crown and root dentin
Term
secondary dentin
Definition
- dentin based on developmental pattern
- formed after root and apical foramen completed
- formed after teeth come into occlusion
- forms on pulpal surface of dentin
- continues to be formed as long as tooth is vital
Term
tertiary dentin
Definition
- dentin based on developmental pattern
- formed in response to external stimuli (caries, attrition, abrasion, restorative procedures, other irritants)
- response to injury
- reactionary or reparative dentin
Term
reactive dentin
Definition
- type of tertiary dentin
- odontoblasts stimulated to synthesize this if the tooth is mildly injured
- odontoblasts must survive injury in order to synthesize this
Term
reparative dentin
Definition
- severe tooth injury or odontoblast death will induce newly formed odontoblast to secrete this
- type of tertiary dentin
-
Term
mantle dentin
Definition
- dentin based on location
- first dentin formed during dentinogenesis
- adjacent to enamel in crown/ cementum in root
Term
cicumpulpal dentin
Definition
- dentin based on location
- all dentin beyond mantle dentin layer
- most of dentin
- can be primary, secondary or tertiary dentin
Term
intertubular dentin
Definition
- dentin based on location
- around and between dentinal tubules
- has many collagen fibers
- mineral content about 70%
Term
intratubular dentin
Definition
- dentin based on location
- lining dentinal tubule
- more highly mineralized (70%)
- contains fewer collage fibers
Term
intratubular dentin
Definition
- deposition of this can narrow dentinal tubule lumen
- can reduce permeability of dentin
Term
sclerotic dentin
Definition
- dentin based on mineral content
- happens when dentinal tubules become filled with minerals such as calcium
- increases with age
- reduces dentin permeability
- may be protective mechanism for pulp
Term
globular dentin
Definition
- dentin based on mineral content
- occurs when calcopsheres increase in size and eventually fuse to for this
- region of dentin where calcospheres are present
Term
calcospheres or globules
Definition
- round accumulations of HAP
Term
interglobular dentin
Definition
- dentin based on mineral content
- hypomineralized dentin trapped between areas with normal mineral content
- likely between mantle and circumpulpal dentin
- high fluoride levels or vit D deficiency
Term
tomes' granular layer
Definition
- histological feature of dentin
- located beneath DCJ in root only
Term
dead tracks
Definition
- histological feature of dentin
- represent areas of dentinal tubules that don't have any odontoblastic processes
- dentinal tubules filled with air
- look like black bands in ground section of tooth
Term
incremental lines of von ebner
Definition
- histological feature of dentin
- represents where dentin has been deposited in daily increments of activity and rest
Term
contour lines of owen
Definition
- histological feature of dentin
- represent physiological alterations in pattern of mineralization because disturbance of some kind
Term
neonatal line
Definition
- histological feature of dentin
- wide contour line of owen
- represents physiologic changes that occur at birth
- seen in primary teeth and first permanent molars
Term
changes in dentin with aging
Definition
- reduction in number of odontoblast
- secretory activity of odontoblasts is reduced but may be reactivated after injury
- increased amount of sclerotic dentin
- dentin might undergo hypomineralization in some areas
Term
pulp chamber
Definition
the shape of the ___ is different for every tooth.
Term
coronal pulp
Definition
- in the crown
- contains pulp horns
Term
radicular pulp
Definition
- in the roots
- called pulp canal
Term
apical foramen
Definition
- opening from pulp at tooth apex
Term
central cells
Definition
pulp develops from the _____ of the dental papilla.
Term
dentin
Definition
pulp has embyrological origin similar to ____ because both tissues are formed from dental papilla.
Term
dentin
Definition
in a formed tooth, ___ surrounds the pulp.
Term
components of pulp
Definition
- loose connective tissues
- several cells
- organic collagen type I
- blood vessels
- nerves
Term
cells of pulp
Definition
- fibroblasts
- odontoblasts
- undifferentiated mesenchymal cells
Term
fibroblasts
Definition
- most numerous cell of pulp
- produce collage fibers
- form and maintain pulp
Term
odontoblasts
Definition
- located in pulp adjacent to dentin
- do not proliferate by mitosis but produce secondary dentin
- produce reactive dentin in response to mild injury
Term
undifferentiated mesenchymal cells (UMC)
Definition
- will differentiate into odontoblasts and secrete reparative dentin in response to severe injury
- decrease in number with age = ability of pulp to respond to severe injury is weakened
Term
blood vessels, nerves, lymphatic tissue
Definition
____ enter and leave pulp at apical foramen and travels through root canals to pulp chamber.
Term
autonomic sympathetic, sensory nerve fibers
Definition
there are _____ and ____ nerve fibers in pulp.
Term
autonomic sympathetic nerve fibers
Definition
- surround some blood vessels in pulp
- regulate areriole diameter and blood flow in capillaries in pulp
Term
afferent sensory nerves
Definition
- found throughout pulp also in dentinal tubules
- pain sensations are transmitted from dentin to pulp
Term
pain fibers in pulp
Definition
- A delta and C fibers
Term
A delta pain fibers
Definition
- myelinated axons
- associated with sharp, quick, localized pain that goes away with stimulus
- drilling, air-drying, application of hyperosmotic fluids, heating/looking dentin can stimulate
Term
c fibers pain fibers in pulp
Definition
- unmyelinated axons
- activated by thermal, mechanical or chemical stimuli reaching deeper parts of pulp
- play role in mediation of dull pain connected with pulpal inflammation
Term
hydrodynamic theory
Definition
- external stimuli applied to exposed dentin causes fluid in dentinal tubules to move
- fluid movement stimulates nerve endings
- how pain sensations are transmitted from dentin to pulp
Term
pulp stones or denticles
Definition
- masses in loose connective tissue
- may be free or attached to dentin surface
Term
true pulp stones
Definition
- made of dentin and have dentinal tubules and odontoblasts
Term
false pulp stones
Definition
- formation caused by calcification of tissue in pulp cavity
- no dentin or dentinal tubules
Term
inductive function of pulp
Definition
- dental papilla interacts with dental lamina to initiate tooth formation
Term
formative function of pulp
Definition
- odontoblasts/UMCs form dentin following injury
Term
nutritional function of pulp
Definition
- blood vessels in pulp carry o2 and nutrients to dentin (no blood supply to support odontoblastic processes)
Term
protective function of pulp
Definition
- sensory nerves in pulp respond with pain
- formation of tertiary/sclerotic dentin protects pulp from bacterial invasion
Term
defensive/reparative function of pulp
Definition
- involves formation of tertiary dentin and initiation of inflammation following trauma or infection
Term
changes in pulp with aging
Definition
- size of pulp chamber decreases in size
- decrease in total number of cells in pulp
- repair following pulpal injury is reduced because UMC are less likely to differentiate to odontoblasts
- am't of collagen fibers increases
-
Term
enamel
Definition
- hardest of all tissues
- >96% HAP
- does not contain any collagen
- made of rods and interrod
- does not have cells, nerve, or blood vessels
- is nonvital tissue
- cannot be repaired
- comes from ectoderm
Term
amelogenesis
Definition
- formation of enamel
Term
ameloblasts
Definition
- differentiate from inner enamel epithelial cells
- comes from ectoderm
Term
6 functional stages of ameloblasts
Definition
- morphogenic
- organizing
- formative
- secretory
- maturation
- protective/desmolytic
Term
formative stage of ameloblast function
Definition
- ameloblasts become columnar secretory cell from cuboidal cell
- thin layer of enamel is secrete on top of mantle dentin
- contains aprismatic enamel
- contains HAP crystals, but not yet organized into enamel rods
Term
secretory stage of ameloblast function
Definition
- columnar ameloblasts develop tome's process
- formation of rods/prismatic enamel
- ameloblast within tome's process secretes enamel rods
- 30% of HAP at this point
Term
tome's process
Definition
- cone-shaped cellular process at secretory end of each ameloblast
- faces DEJ
Term
enamel matrix
Definition
ameloblasts secrete ____.
Term
enamel matrix
Definition
___ does not contain collagen type I
Term
amelogenin
Definition
- main enamel protein
Term
maturation stage of ameloblast
Definition
- ameloblasts undergo changes in morphology/function
- many die
- ameloblasts no longer function to secrete enamel matrix
- now mineralize existing enamel from 30-96% HAP
Term
ruffled-ended ameloblasts in maturation stage
Definition
- add calcium phosphate and bicarbonate ions to enamel matrix
Term
smooth-ended ameloblasts in maturation stage
Definition
- remove proteins and water from enamel matrix
Term
ruffled-ended + smooth-ended ameloblasts
Definition
- creates enamel with 96% HAP
Term
protective or desmolytic stage of ameloblast
Definition
- ameloblasts and other cells collapse to form reduced enamel epithelium
Term
reduced enamel epithelium
Definition
- protects crown
- participate in tooth eruption
- forms part of gingiva
- formed from collapsed ameloblasts and cells
Term
apposition
Definition
- layering of mineralized tissues
- dentin - enamel - dentin - enamel
Term
rods
Definition
- prisms
Term
interrod enamel
Definition
- interprismatic enamel
Term
enamel rods
Definition
- enamel crystals arranged in rows
- extend from DEJ to outer surface of enamel
- varies in length depending on location
- 8-12 million of these in enamel
- parallel to each other
- perpendicular to DEJ
Term
bands of hunter-schreger
Definition
- alternating broad light and dark bands beginning at DEJ
Term
enamel cross striations
Definition
- cross-striations across enamel rods
Term
striae of retzuis or lines of retzius
Definition
- growth lines that represent 7-9 days of enamel crystal elongation
- run obliquely across enamel rods
Term
neonatal lines
Definition
- accentuated line of retzius
- represents disruption in ameloblast activity due to physiological changes at birth
- present in primary teeth and 1st perm. molar
Term
enamel lamellae or cracks
Definition
- start at enamel surface and extend into enamel nearly all the way to dentin
- may be caused by trauma or developmental problem
- filled with enamel matrix proteins, salivary proteins or organic debris from oral cavity
- potential area of bacterial invasion
Term
enamel tufts
Definition
- attached to DEJ and extend perpendicular to DEJ into enamel
- hypomineralized areas
- no known clinical significance
Term
enamel spindles
Definition
- represent ends of odontoblastic processes that cross DEJ into enamel
- no major clinical significance, but may allow materials to cross from dentin to enamel
Term
gnarled enamel
Definition
- over cusps of teeth, enamel rods are twisted
- lack of room for deposition of enamel at cusp tips
- may confer strength or resistance to fracture in this region during mastication
Term
perikymata
Definition
- surface depressions on tooth crown that represents ends of striae of Retzuis
- usually worn away quickly on erupted teeth
Term
cementum
Definition
- mineralized tooth tissue that covers root
- component of peridontium
- may form at root apex as a result of tooth eruption in response to attrition
Term
cementum
Definition
- functions to attach the root to the surrounding alveolar bone by anchoring periodontal ligament
- might contain cells
- no blood vessels or nerves
- forms throughout vital life of tooth
- may cause apical constriction by narrowing apical foramen
Term
cementogenesis
Definition
- formation of cementum
Term
cementoblasts
Definition
- form cementum
- derived from cells of dental follicle (sac) [from ectomesenchyme] surrounding the root
- single layer of cells on cementum next to periodontal ligament
Term
cementogenesis stage 1
Definition
- cementoblasts secrete pre-cementum
- no cells, no mineral content, no blood vessels or nerves in pre-cementum
- pre-cementum contains collagen type I
Term
pre-cementum
Definition
- no mineral content
- no cells
- no blood vessels or nerves
- contain collagen type I
- secreted by cementoblasts
Term
cementogenesis stage 2
Definition
- pre-cementum mineralized
- 50% HAP (closest to bone)
- some cementum may have cells trapped in mineral
Term
50% in cementum
Definition
- % of HAP most similar to bone
Term
cementocytes
Definition
- cells surrounded by cementum
- receive o2 and nutrients from periodontal ligament
Term
AEFC (acellular extrinsic fiber cementum)
Definition
- no cementocytes
- sharpey's fibers insert to anchor periodontal ligament
- covers cervical 1/3-2/3 of root
- major role in anchoring root to the PDL
Term
CIFC (cellular intrinsic fiber cementum)
Definition
- contains cementocytes
- contains collagen type I but no sharpey's fibers
- not as important in root attachment
- found in root furcations, apical root and resorption, root fracture sites and following wounding
Term
root apex, interradicular areas, cervically
Definition
cementum is thickest at _____ and ____ of multirooted teeth.
cementum is thinnest _____.
Term
incremental growth lines in cementum
Definition
- reflect appositional growth of cementum
- one line to next may represent one year of cementum growth
- used to determine age of humans and animals
Term
CIFC
Definition
- type of cementum deposited slowly through life of tooth
Term
dentin
Definition
____ continues to be formed throughout life of tooth, deposited on pulp side and narrows pulp chamber.
Term
enamel
Definition
___ has no cells, therefore cannot be regenerated once tooth erupts.
Term
cementum
Definition
____ continues to form on outside of root and may narrow the apical foramen.
Term
O-overlap
Definition
- cementum overlaps enamel at CEJ
- most common relationship of cementum to enamel
Term
M - meet
Definition
- cementum and enamel meet end to end
Term
G- gap
Definition
- there is a space between cementum and enamel, exposing dentin
Term
odontoclasts, cementoblasts
Definition
____ resorb cementum and _____ deposit new cementum.
Term
CIFC
Definition
new cementum is usually _____.
Term
crown
Definition
root formation begins after ____ is formed to the cervical loop.
Term
inner and outer enamel epithelium
Definition
____ and ____ from enamel organ form HERS.
Term
HERS
Definition
- regulator of root formation
- size/shape/length/number
- induces differentiation of odontoblasts from dental papilla to produce root dentin
- induces differentiation of dental follicle into cementoblasts to produce cementum
Term
HERS
Definition
- induces differentiation of odontoblasts from dental papilla to produce root dentin
Term
dentin
Definition
____ is formed before cementum.
Term
odontoblasts
Definition
____ produce root/radicular dentin
Term
HERS
Definition
- degenerates in area of root where dentin has been secreted, causing breaks in continuity
Term
dental follicle sacs, cementoblasts
Definition
cells from _____ pass through breaks in HERS and contact root dentin.
these cells differentiate into ____ and produce cementum.
Term
epithelial rests of malassez
Definition
- cells form islands in periodontal ligament in adult
Term
root
Definition
continued proliferation of IEE and OEE allow the ____ to grow.
Term
epithelial diaphragm
Definition
- formed by HERS bending inward at growing apical end
- determines number of roots that will form
Term
eruption
Definition
- vertical movement of tooth from its nonfunctional position in bone to functional occlusion
Term
passive eruption
Definition
- does not involve tooth movement but occurs due to apical recession of gingival tissues exposing more tooth structure into oral cavity
Term
moment of eruption/emergence
Definition
- time when any part of crown can be seen through oral epithelium
Term
reduced enamel epithelium
Definition
- formed during protective stage in ameloblast life cycle when they flatten
- covers enamel crown until tooth erupts
Term
fusion of REE with overlying oral epithelium
Definition
- when primary/secondary tooth ready to erupt, reduced enamel epithelium fuses with epithelium lining oral cavity
Term
breakdown of overlying connective tissue
Definition
- digestive enzymes degrade tissues and a tunnel is formed for the tooth to erupt
Term
emergence into the oral cavity
Definition
- penetrates through fused REE and oral epithelium
- crown enters oral cavity
- epithelial layers peel off crown as it is erupted
Term
epithelial layers
Definition
____ peel off crown as it erupts and eventually becomes part of gingiva.
Term
the cell bodies are located in the pulp
Definition
which of the following is true of odontoblasts?
- they are derived from ectoderm
- they die as tooth is erupting
- their main function is to resorb dentin
- cell bodies are located in the pulp
Term
96%
Definition
what is the percentage of HAP in mature enamel?
- 50
- 70
- 96
- 100
Term
their main function is to resorb dentin
Definition
which of the following is true of odontoclasts?
- they are derived from ectoderm
- they die as tooth is erupting
- their main function is to resorb dentin
- cell bodies are located in the pulp
Term
they die as the tooth is erupting
Definition
which of the following is true of ameloblasts?
- they are derived from ectomesenchyme
- they die as tooth is erupting
- their main function is to resorb dentin
- cell bodies are located in the pulp
Term
they are derived from ectomesenchyme
Definition
which of the following is true of cementoblasts?
- they are derived from ectomesenchyme
- they die as tooth is erupting
- their main function is to resorb dentin
- cell bodies are located in the pulp
Term
70%
Definition
what is the percentage of HAP in mature dentin?
- 50
- 70
- 96
- 100
Term
50%
Definition
what is the percentage of HAP in mature cementum?
- 50
- 70
- 96
- 100
Term
50%
Definition
what is the percentage of HAP in mature bone?
- 50
- 70
- 96
- 100
Term
pulp
Definition
dental follicle (sac) forms all of the following except one. which is the exception?
- pulp
- periodontal ligament
- cementum
- alveolar bone
Term
periodontal ligament
Definition
dental papilla forms all of the following except one. which is the exception?
- pulp
- periodontal ligament
- dentin
Term
enamel
Definition
dental lamina forms which of the following?
- pulp
- periodontal ligament
- cementum
- enamel
Term
cemetoblasts
Definition
which of the following cells produces pre-cementum?
- cementoclasts
- cementocytes
- cementoblasts
- odontoclasts
Term
odontoclasts
Definition
which of the following cells resorbs cementum?
- cementoclasts
- cementocytes
- cementoblasts
- odontoclasts
Term
cementocytes
Definition
which of the following cells is trapped in mineral?
- cementoclasts
- cementocytes
- cementoblasts
- odontoclasts
Term
enamel
Definition
all of the following are derived from ectomesenchyme except one:
- enamel
- dentin
- cementum
- pulp
Term
dentinal tubule fluid
Definition
the hydrodynamic theory of dentin sensitivity is based on the movement of:
- lymph
- dentinal tubule fluid
- blood in capillaries
- tissue fluid in pulp
Term
root must be resorbed
Definition
which of the following must occur for the exfoliation of primary teeth?
- enamel must be destroyed
- cementum must be formed on root
- root must be resorbed
- new alveolar bone must be formed around the tooth
Term
shape of crown
Definition
HERS determines all of the following except:
- shape of roots
- number of tooth roots
- root length
- the shape of crown
Term
HAP
Definition
the major mineral component of dentin is:
- collagen type I
- dentin proteins
- sodium chloride
- HAP
Term
oxytalan fibers
Definition
which of the following is the major elastic component of the periodontal ligament?
- elastic fibers
- oxytalan fibers
- elaunin
- reticular fibers
Term
consists of basal lamina and hemidesmosomes
Definition
the epithelial attachment of the gingiva:
- attaches the gingiva to alveolar bone
- is absent in erupted tooth
- consists of basal lamina and hemidesmosomes
- permits tooth root to be in direct contact with fluids in oral cavity
Term
PDL
Definition
- band of connecitve tissues btwn tooth cementum and alveolar bone
Term
periodontium
Definition
- gingiva, PDL, cementum and alveolar bone
Term
PDL
Definition
- attach tooth to surrounding alveolar bone
- contains cells, blood vessels and nerves
- no HAP
Term
PDL
Definition
- develops at same time that root begins to form
- forms from dental follicle (sac)
Term
PDL
Definition
- connective tissues
- has cells
- fibers
- extracellular matrix
Term
fibroblast
Definition
- most numerous cell in PDL
- synthesize collagen fibers
- produce sharpey's fibers that anchor PDL to cementum
Term
fibers and extracellular matrix in PDL
Definition
- collagen type I
- oxytalan fibers
- glycoproteins, proteins, 70% water
Term
oxytalan fibers in PDL
Definition
- fibrous component of PDL
- located near blood vessels
- might function to stabilize blood vessels
Term
principal fibers of PDL
Definition
- fibrous component in PDL
- bundles of collagen type I
- adapt to stresses placed on PDL
- one end attached to cementum
- other end attached to bone or cementum
Term
principal fiber/alveolodental fiber groups
Definition
- alveolar crest
- horizontal
- oblique
- apical
- interradicular
Term
alveolar crest fiber group
Definition
- cementum just below CEJ to alveolar crest
- resist tilting, intrusive, extrusive, rotational
Term
intrusion
Definition
- apical displacement
- leads to fracture of alveolar socket
Term
extrusion
Definition
- movement of tooth in occlusal direction
- periodontal ligament usually town
Term
avulsion
Definition
- complete displacement of tooth
- PDL severed
- alveolar bone fractured
Term
horizontal fiber group
Definition
- cervical third of root at right angles to long axis
- attach cementum to bone apical of alveolar crest
- resists tilting and rotation
Term
oblique fiber group
Definition
- most numerous group
- apical 2/3 of root
- fibers slant from cementum to alveolar bone
- resist intrusive forces
- suspends tooth in socket
Term
apical fiber group
Definition
- radiates around apex and forms base of tooth socket
- resists extrusive, tilting and rotational forces
Term
interradicular fiber group
Definition
- only in multirooted teeth
- attach cementum to bone in areas of interradicular septum
Term
transseptal fiber group
Definition
- fibers embedded in cementum of adjacent teeth
- pass over alveolar crest
- ensure teeth remain in proper relationship to eachother
- aka interdental ligament
Term
fibroblasts
Definition
the PDL is well-vascularized because of the metabolic needs of ______ involved in high collagen turnover rates.
Term
autonomic sympathetic
Definition
_____ axons generally follow blood vessels and innervate smooth muscle cells to regulate dialation
Term
afferent sensory fibers
Definition
____ fibers can be noci or mechanoreceptors
Term
functions of PDL
Definition
- supportive/attachment
- formative
- resorption/remodeling
- sensory
- nutritive
Term
alveolar bone
Definition
- collagen type I
- cells
- blood vessels
- nerves
- 50% HAP
- surrounds tooth
Term
alveolar bone proper
Definition
- solid plate of bone surrounding periodontal ligament
- compact bone
- sharpey's fibers connect here
Term
alveolar process
Definition
- rests on basal bone
- surrounds tooth
Term
basal bone
Definition
- beneath alveolar process
Term
lamina dura
Definition
- radiographic term for alveolar bone proper
- radiopaque line around tooth root
- if absent, indicates periodontal pathology
Term
bundle bone
Definition
- histological term for alveolar bone proper
- area of alveolar bone proper where sharpey's fibers of PDL attach
Term
cribiform plate
Definition
- anatomic term for alveolar bone proper
- blood vessels and nerves penetrate through foramina
Term
cancellous or trabecular bone
Definition
- aka spingiosa or medullary
- contains bone marrow
- young = many blood forming cells
- old = fat tissue
Term
cortical plate
Definition
- outer and inner plates of compact bone on buccal and lingual surfaces of max/mand
- attachment site for muscle
- similar to bone found in other areas of body
Term
fully edentulous
Definition
- individual has no teeth at all in upper or lower jaw
Term
partially edentulous
Definition
- missing one or more teeth
Term
alveolar crest
Definition
- most cervical or coronal region of alveolar bone
- 1/2mm apical to CEJ
- uniform height in healthy mouth
Term
interradicular septum
Definition
- bone between roots of same tooth
Term
interdental septum
Definition
- bone between two neighboring teeth
Term
alveolar bone
Definition
- developed by intramembranous ossification
Term
mandibular condyle
Definition
- formed by endocondral ossification
- continues growth until 2nd/3rd decade of life
Term
1st, 1st
Definition
- meckel's cartilage is hyaline cartilage present in ____ pharyngeal arch located near mandibular prominence of ___ arch.
Term
most of mandible
Definition
___ forms alongside meckel's cartilage
Term
osteoclasts, osteoblasts
Definition
____ resorb bone on pressure side of orthodontics while ____ form new bone on tension side.
Term
true
Definition
T/F: crown enamel/crown dentin are formed to cervical loop before HERS is formed from IEE and OEE.
Term
false, HERS is formed before dental papilla --> odontoblasts build dentin
Definition
T/F: HERS is formed after dental papilla cells close to HERS become odontoblasts and build dentin.
Term
true!
Definition
T/F: dental papilla cells become odontoblasts and form root dentin before the cells of HERS degerate?
Term
true!
Definition
T/F: HERS degernate before dental follicle contact root dentin and become cementoblasts.
Term
true!
Definition
T/F: dental follicle cells contact root dentin and become cementoblasts before cementoblasts form root cementum
Term
TRUE!
Definition
T/F: cementoblasts form root cementum before epithelial rests of Malassez are formed.
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