Dental Morphology Flashcards
root formation will begin at the cervical loop when what is completed
the crown
when enamel formation reaches the cervical loop, what will begin
root formation
as soon as the crown is completed, what will the crown do
it will start to erupt
an extension of the cervical loop that has an infolding of the epithelial sheath is what
root sheath
an infolding of the epithelial sheath is called the
epithelial diaphragm
cells of the OEE and IEE at the cervical loop proliferate and form the
Epithelial Rooth Sheath (ERS)
another name for the epithelial root sheath (ERS) is the
Hertwig’s root sheath
the epithelial diaphragm is part of the
Epithelial Rooth Sheath (ERS)
when the root sheath extends, it breaks up and lets the ectomesenchyme reach the dentin and deposit
cementum
The Epithelial Rooth Sheath (ERS) induces formation of ________ and _________ formation
odontoblasts ; dentin
as root dentin is formed, tooth begins
eruptive movement
cementoblasts deposit
cementum
during root development and eruption, portions of the Epithelial Rooth Sheath (ERS) are seen as fragments along the
side of the root
the broken remnants of Epithelial Rooth Sheath (ERS) are called what 2 names?
Epithelial Rests OR Epithelial Cells Rests of Malassez
Epithelial Rests aka Epithelial Cells Rests of Malassez can be used as
stem cells to originate other tissues
root dentin induces cells of the dental follicle to differentiate into
cementoblasts (forming cementum)
cells of the dental follicle will begin to form the
PDL
as soon as we have formation of roots, we see fibroblasts in the space derived from ____________ which will organize themselves into collagen fibers which will be the origin of _______
ectomesenchyme ; PDL
fibroblasts derived from ectomesenchymal tissue of the dental follicle will synthesize collagen for the
PDL
extensions of the epithelial root sheath (ERS) will subdivide the _________, providing _______ to develop
apical foramen ; multiple roots
furcation is determined by where the ___________ meet
epithelial diaphragms
what forms when there is an opening in the epithelial root sheath (ERS) that allows for contact of the ectomesenchyme outside of the tooth and ectomesenchyme inside the pulp cavity (this is due to a failure of root dentin formation)
accessory root canals
what pathology?
when the epithelial diaphragm fuses very low and you have a LARGE pulp cavity and very short roots and usually has relatively weak anchoring to the alveolar bone
taurodontia
simple teeth will have fewer _____ than complex teeth
roots
soft tissue is always _____ when compared to hard tissue
1st
primary vasculature is directed to
major cusps
_____ controls crown shape
enamel knot
teeth that do NOT have replacement
molar
primary dentition formula
I 2/2 C 1/1 M 2/2 =10
permanent dentition formula
I 2/2 C 1/1 P 2/2 M 3/3 =16
all teeth derive from the
dental lamina
molars originate by a ____ extension of the _______ from the last ________
posterior ; dental lamina ; premolar
premolars originate from
back to front
incisors originate from
front to back
molars originate from
front to back
example: i2 is dependent on ___ to originate
i1
If you damage M2, will you still have M1? What about M3?
M1 - yes
M3 - no
If you damage premolar 1, will premolar 2 be okay?
yes, premolar 2 will be fine because it is already developed before premolar 1
If you damage premolar 2, will premolar 1 be okay?
No, if you damage PM2 you will not have PM1 because premolars originate from back to front
few missing teeth
hypodontia
no teeth
anodontia
peg laterals
microdontia
giant teeth
macrodontia
a condition of supernumerary teeth (extra teeth)
hyperdontia
2 crowns develop from a single enamel organ/root
gemination
2 teeth that fuse together
fusion
when the root sheath gets fused together through the cementum of the roots
concrescence
trauma that causes angulation between the crown and root
dilaceration
enamel in the root
enamel pearl
what results when cells of the root sheath remain adherent to developing dentin and induce enamel formation
enamel pearl
when the root sheath doesn’t detach and allow cells from ectomesenchyme to get behind and produce cementum
enamel pearl
fluid filled remnants of the REE seen in infants
gingival cysts
The root of the tooth is comprised of
dentin
cells of the IEE induce the
differentiation of odontoblasts in crown formation and they
will also induce differentiation of odontoblasts for ______
root formation
cells of the IEE and OEE proliferate at the cervical loop proliferate to form a double layer of cells known as
Hertwigs epithelial root sheath
Hertwigs epithelial root sheath encloses the primary ______
apical foramen
cells of the dental papilla which neighbor the IEE cells differentiate into
odontoblasts
as root formation begins, the tip of the root remains essentially _______
the crown of the tooth
begins to move _______ towards the oral cavity
stationary (it does not grow deeper) ; vertically
as the root lengthens and the crown moves vertically, portions of the root sheath are
stretched –> the sheath surrounding the root
becomes fragmented and separated from the root
dentin –> clusters of epithelial cells along the root surface are known as
epithelial cell rests of Malassez
what forms from the fragmentation of the epithelial
root sheath occurs and root dentin is exposed to
ectomesenchymal cells of the dental follicle
cementum
ectomesenchymal cells at the
periphery of the dental follicle differentiate into osteoblasts
which produce
osteoid
During development we have ___ placodal precursors for
the four families along the dental lamina: incisor, canine
and postcanine precursor
3
when the epithelial cells of
the root sheath fail to detach from the developing root aka they remain adhered - what does this create
exposed root dentin
when epithelial cells of the root sheath in the cervical area near a furcation area remain adherent to developing root dentin and induce the formation of ameloblasts and enamel - what is formed?
enamel pearls
foundational tissues
dentin + enamel
changing shape of cusp depends on rate of _______ deposition
ameloblast
what integrates dentin
calcospheric deposits
rodless enamel is ____ and is ALWAYS by the ____
first ; DEJ
% of inorganic material of dentin
% of inorganic material of enamel
dentin - 70%
enamel - 96%
calcospheric deposits allows for mineralization of
dentin
you need to have a complete _____ to begin root formation
crown
the epithelial diaphragm constricts _____ and can subdivide to create more ____
pulp ; roots
