when does odontogensis start for
- primary teeth
- permanent teeth
primary teeth
- 6th-8th week of prenatal development
permanent teeth
- 20th week of prenatal development
in terms of tooth development, what causes hypodontia/anodontia and hyperdontia?
hypodontia/anodontia
- lack of dental lamina
hyperdontia
- multiple dental lamina
what is another name for pharyngeal arches?
visceral arches
what are the 3 primary germ layers in early embryo?
ectoderm
mesoderm
endoderm
1st pharyngeal arch
- also called?
- give rises to (4)
mandible arch
- maxilla
- palate
- mandible
- muscles of mastication
Merkel’s cartilage
- where is it found?
- gives rise to?
1st pharyngeal arch
incus and malleus of middle ear
Why is Merkel Cartilage important? (3)
- acts as “template”
- for mandible to form
- by perichondral/intramembranous ossification
2nd pharyngeal arch
- also known as?
- hyoid arch
what is Reichert’s cartilage?
is what all the cartilage in 2nd pharyngeal arch is called
tooth germ is organised in to 3 parts. What are they?
- enamel organ
- dental papillae
- dental follicle
what is cervical loop?
Is where outer and inner enamel epithelium joins
HERS
- stands for?
- what is it?
Hertwigs Epithelial Root Sheath
Is the proliferation of epithelial cells located at cervical loop.
cell Rest of Mallasez
- what is it?
- may attribute to what dental condition?
residual cell from HERS
radicular cyst
Gland of Serres
- what is it?
- may attribute to what dental condition?
remnants of dental lamina
OKC
how does the following cells help in tooth development?
- enamel organ
- dental papillae
- follicle
enamel organ
- ameloblast
- forms enamel
dental papilae
- forms odontoblast
- forms dentin and pulp
follicle
- forms cementoblast, osteoblast, fibroblast
- cementum, PDL
what are the tooth developmental stages (4)
initiation
bud
cap
bell
what protein regulates the tooth development stage?
sonic hedgehog
