Tooth Development Flashcards
the mature tooth rests in a boney
socket and is held in place by
_________
connective tissue
during initiaton of tooth development, ectoderm lining stomodeum gives rise to _______ and then to _______; adjacent to deeper ectomesenchyme, which is derived from the ________ where both tissue types are separated by a _______
oral epithelium, dental lamina, neural crest
cells, basement membrane
the bud stage begins around the ______ week
eighth
the main process of the bud stage is ________
proliferation
the bud stage begins the growth of dental lamina into bud shape that penetrates growing ________
ectomesenchyme
the cap stage begins around the ________ week
ninth to tenth
the main processes of the cap stage are _______, _______, and ________
proliferation, differentiation, morphogenesis
the cap stage begins with the formation of tooth germ as _______ forms into cap shape that surrounds inside mass of _______ , with an outside mass of dental sac (DS), both from the
ectomesenchyme
enamel organ (EO), dental papilla(DP)
the bell stage begins around the _________ week
eleventh to twelth
the main processes of the bell stage inlcude ________, _______, and _______
Proliferation, differentiation, morphogenesis
during the bell stage the differentiation of enamel organ into bell shape with ______ cell types and dental papilla into ______ cell types
four, two
the apposition stage begins at various times and the main processes include ______ and ______
induction, proliferation
during the apposition stage the dental tissue types are secreted in successive layers as _______.
matrix
the maturation stage begins at various times and the main process is _________
maturation
during the maturation stage, the dental tissue types fully ________ to mature form
mineralize
_______ is a process wherein one tissue directs the development of another adjacent tissue and mediated by ________ or factors released by the ________
induction, cell-contact, inducing
tissue
induction signals usually regulate ________ thereby leading the target cells toward differentiating into a specific cell type
gene transcription,
Induction can be ______ and _______ so that tissue A induces
tissue B and in turn later on tissue B then induces tissue A
serial, reciprocal
Primary Epithelial band gives rise to ______ and ________
Dental lamina, Vestibular Lamina
the epithelial band is a result of _______ and change of orientation of mitotic cells
mitosis
meckel’s cartilage is part of the ectomesenchyme that gives rise to part of the _______ and mental portion of the _______
inner ear, mandible
The ________ is requisite for tooth development
mandibular epithelium
the ectomesenchyme cells will become the _______
dental papilla
two important ligands involved in tooth development include __________ and __________
fibroblast growth factors (FGF), bone morphogenetic proteins
Transcription factors are proteins in the nucleus that regulate the
pattern of _______
gene expression
Ectoderm derived FGF-8 regulates gene expression in ________
ectomesenchyme
FGF-8 induces _______ and ______ in
ectomesenchyme very early in development
Lhx-6, Lhx-7
FGF-8 is highly expressed in the ______ arch ectoderm but if the ______ arch ectoderm is used in culturing experiments the expression of FGF-8 is low and tooth placodes do not form
first, second
Expression of the PAX9 transcription factor in ectomesenchymal cells is required to differentiate into __________
DENTAL ectomesenchymal cells
dental placode formation requires _________ for mitosis, ________ for apoptosis and cell division and _________
transcription factor p63, tumor necrosis factor, ectodysplasin
Ectodysplasin (Eda) transmembrane
protein that can be cleaved by ______ to produce a secreted form, involved in morphogenesis were loss of function causes ______ and over expression caused _______
furin, fewer teeth, extra teeth
sonic hedgehog (shh) has roles in ______ development, _______ differentiation, ______ morphogenesis, ______ development, and forming the ______ of the body
limb, neural, facial, hair and feather, midline
sonic hedgehog is important for _______ and ________
invagination, tooth development
Once ectomesenchyme has been
under the control of the epithelium in early tooth development it now is competent to drive tooth formation from ________ and later on the _______ takes over
skin epithelium, neural crest
during tooth bud proliferation the _______ invaginates and moves into the ectomesenchyme that is made up of _________
oral ectoderm, neural crest cells
the tooth bud stage is the stage where the ______ has a significant effect directing the development of the tooth
ectoderm
The ectoderm of the dental lamina plus the underlying ectomesenchyme develop into the _______
tooth germ
during the cap stage as the ectoderm develops and invaginates
into the ectomesenchyme it begins to surround the cells that will become the _______
dental papilla
the six molecules involved in the bud and cap stages includes _____, ______, _____, ______, _____ and _____
msx-1, bmp-4, bmp-2, SHH, activin-BA, Pax-9
SHH is needed for the _____ stage
cap
activin-BA and Pax-9 permit development past the ____ stage
bud