Tooth Development (complete) Flashcards
What is the stomatodeum
the primitive oral cavity
What borders the stomatodeum
the neural plate
the cardiac plate
What separates the stomatodeum from the foregut
the buccopharyngeal membrane
What happens to the buccopharyngeal membrane
it disintegrates in the 4th week
what lines the stomatodeum
ectoderm
what initiates the development of the face
the formation of the stomatodeum
what is the oral epithelium
a primitive two or three cell thick layer of epithelium that covers embryonic connective tissue
from what does the dental lamina develop
a portion of the oral epithelium
What is dental lamina
the horse shoe shaped band of epithelial tissue that will develop into the teeth and periodontium (along with ectomesenchyme)
When does odontogenesis begin
the 6th week
What are the two tissues that develop into teeth
- dental lamina
2. ectomesenchyme
When do primary teeth begin to form
4 months in utero
when do permanent teeth begin to form
at birth
What initiates and governs tooth development
ectomesenchymal interactions
What leads to the differentiation of ectomesenchyme
secretion of growth factor by the dental lamina
What is the ectomesenchyme formed from
mesoderm with neural crest cells sprinkled in
What separates the dental lamina from the ectomesenchyme
a well defined basal lamina
What signifies the start of odontogenesis
the appearance of the dental lamina
What are the stages of dental lamina development
- oral epithelium (no invagination)
- primary epithelial band (slight invagination)
- Dental lamina (invagination)
What is adontia
congenital absence of all teeth
what causes adontia
ectodermal dysplasia
(defect in the ectoderm derived tissues)
no tooth buds are formed
What is hypodontia
1-5 teeth missing
what is oligodontia
6 or more teeth missing
What is hyperdontia
extra teeth (supernumerary teeth)