Tooth Eruption Flashcards
Eruption is part of __________________
tooth development
thickening of the epithelium through cell division determines the position where a row of teeth will form
primary epithelial band
further epithelial thickening and bifurcation into dental and vestibular lamina
dental and vestibular laminae
Invagination of DL determines the locations where individual teeth will
develop. Invagination of DL is stimulated by ectomesenchymal cells
expressing Pax9. Tooth type is also determined at this stage, according to
other transcription factors expressed in the ectomesenchyme
bud stage
Beginning of tooth morphogenesis and histodifferentiation processes. The
DL forms the enamel organ (EO). Cells of the EO will differentiate into inner
and outer enamel epithelia, stellate reticulum and stratum intermedium.
EMC will differentiate into dental follicle and dental papilla
cap stage
Extension of cervical loop. Enamel knot(s) determine formation of cusps.
bell stage
appositional deposition of dentin and enamel
late bell stage
Cervical loop transforms into Hertwig epithelial root sheet (HERS), which
becomes an organizing center of root formation. Dentin is deposited
alongside HERS. The HERS fragments and cells of dental follicle deposit
cementum and form PDL. Once the length of a root is complete, HERS
changes its direction inward leading to narrowing of the apical foramen
root formation
primary oral cavity is lined with what
ectoderm derived epithelium
beneath epithelium, there is what
ectomesenchyme
areas of the oral epithelium where dentition will form thicken to form the ________________
primary epithelial band
the primary epithelial band splits into what
dental lamina and vestibular lamina
dental lamina will develop into buds where what will form
individual teeth
where a tooth will form there is invagination of the dental lamina into a ________ and condensation of _____________ around it
bud
ectomesenchyme
what stage is the type of tooth and position determined
bud stage
the ________ forms from the dental lamina and starts to develop different cell layers
enamel
what stage does enamel form in
cap stage
what cell layers develop from the enamel/dental lamina
outer enamel epithelium
stratum reticulum
inner enamel epithelium
stratum intermedium
cells in the ectomesenchyme form the _____________ and the ______________
dental follicle and the dental papilla
when do the dental follicle and dental papilla form
cap stage
cells continue to differentiate and the stratum intermedium is evident in this stage
bell stage
where the outer enamel epithelium joins the inner enamel epithelium and extends apically
cervical loop
when does the cervical loop form
bell stage
the enamel knots formed in the bell stage stimulate growth of ________
cusps
the outer cells of the dental papilla become ___________ that secrete dentin
odontoblasts
when is dentin secreted
apposition stage
cells in the inner enamel epithelium become __________ that secrete enamel
ameloblasts
when is enamel secreted from ameloblasts
apposition stage
once crown formation is complete, the developing tooth does what
begins to erupt
while the tooth erupts, what is still forming
roots
what forms the hertwig’s epithelial root sheath
cervical loop
what does HERS guide
root formation
when do primary teeth start developing
6th week of prenatal development
when do primary teeth start erupting
6 months old
when do permanent teeth start developing
14th week of prenatal development
when do permanent teeth begin erupting
6 years old
what teeth are nonsuccedaneous
first, second, and third molars
develop from successional dental lamina lingual to developing primary teeth
succedaneous teeth
develop from posterior extension of dental lamina called the accessional dental lamina
nonsuccedaneous teeth
in late cap/early bell stage of the primary tooth, the lingual portion of the dental lamina becomes the what
successional lamina
arises by posterior growth of the general dental lamina
accessional lamina
what does accessional lamina give rise to
molar teeth
permanent premolars, incisors, and canines arise from
successional lamina
what are the three phases of tooth eruption
pre-eruptive
pre-functional
functional
movement of the developing teeth within the jawbone
pre-eruptive phase
when does the pre-eruptive phase take place
during crown formation, before eruption
what does pre-eruptive phase require
bone remodeling
succedaneous teeth develop ___________ to primary teeth
lingual
after crown formation is complete, ameloblasts secrete a _____________ over the tooth
dental cuticle
the enamel organ compresses in the pre-eruptive phase to form the
reduced enamel epithelium
eruptive movement of teeth into functional positions within the jaw
pre-funcitonal phase
when does the pre-functional phase occur
after crown is complete
when does the pre-functional phase end
when the tooth is fully erupted and makes contact with opposing tooth
in the pre-functional phase the reduced enamel epithelium fuses with the ___________ lining the oral cavity
oral epithelium
the reduced epithelium releases enzymes to disintegrate the __________ part of the fused tissue
central
as the tooth erupts, the ________ part of the fused epithelium peels back
coronal
the fused tissue that remains at the neck of the erupting tooth will form an initial ______________ around the tooth
junctional epithelium
as the cusp of the tooth pierces through the fused epithelial layer, the _____________ still covers the surface of the crown
dental cuticle
starts once the teeth are in occlusion
functional phase
when does the completion of the root take place
functional phase
when does primary dentition erupt
6 months to 2 years
when does primary dentition shed
6 to 12 years
when does the permanent dentition erupt
6 years to about 17-21 years
what primary teeth erupt first
mandibular central incisors
when do primary mandibular central incisors erupt
6 months
what are the last teeth to erupt in the primary dentition
maxillary second molars
when do primary maxillary second molars erupt
25 months
generally speaking, when is primary eruption complete
30 months or 2.5 years
what is the eruption order of the primary dentition
central incisors
lateral incisors
1st molars
canines
2nd molars
when do primary mandibular central incisors erupt
6-10 months
when do primary maxillary central incisors erupt
8-12 months
when do primary maxillary lateral incisors erupt
9-13 months
when do primary mandibular lateral incisors erupt
10-16 months
when do primary maxillary 1st molars erupt
13-19 months
when do primary mandibular 1st molars erupt
14-18 months
when do primary maxillary canines erupt
16-22 months
when do primary mandibular canines erupt
17-23 months
when do primary mandibular 2nd molars erupt
23-31 months
when do primary maxillary 2nd molars erupt
25-33 months
what are the first primary teeth to shed
central incisors
what does tooth shedding require
osteoclasts and odontoclasts
resorb alveolar bone between the primary and secondary teeth
osteoclasts
resorb the dentin, cementum and a portion of the enamel crown from the primary tooth
odontoblasts
what permanent tooth erupts first
first molars
when do permanent first molars erupt
6 years old
what are the last permanent teeth to erupt
third molars
when do permanent third molars erupt
17-21 years
what is the eruption order for the permanent dentition
1st molars
central incisors
lateral incisors
mandibular canine
1st premolars
2nd premolars
maxillary canines
2nd molars
3rd molars
when do permanent mandibular and maxillary 1st molars erupt
6-7 years
when do permanent mandibular central incisors erupt
6-7 years
when do permanent maxillary central incisors erupt
7-8 years
when do permanent mandibular lateral incisors erupt
7-8 years
when do permanent maxillary lateral incisors erupt
8-9 years
when do permanent mandibular canines erupt
9-10 years
when do permanent maxillary 1st premolars erupt
10-11 years
when do permanent mandibular 1st premolars erupt
10-12 years
when do permanent maxillary 2nd premolar erupt
10-12 years
when do permanent mandibular 2nd premolars erupt
11-12 years
when do permanent maxillary canines erupt
11-12 years
when do permanent mandibular 2nd molars erupt
11-13 years
when do permanent maxillary 2nd molars erupt
12-13 years
when do permanent maxillary and mandibular 3rd molars erupt
17-21 years
