Lecture 2- Development And Morphology Of Primary Teeth Flashcards
What are the 4 stages in tooth development
Growth
Calcification
Eruption
Attrition
What are the processes in tooth development during growth
Initiation or bud stage
Proliferation of cap stage
Histodifferentiation (early bell stage)
Morphodifferentiation (late bell stage)
Apposition
What is the germ layer that is not usually involved in tooth formation?
Endoderm
What germ layer is responsible in formation of enamel, it also stimulates odontoblast and determines crown and root shape
Ectoderm
This germ layer forms the dentin, pulp, cementum, pdl and alveolar bone
Mesoderm
When does early stages of odontogenesis become evident?
6 weeks of life
This is a band of epithelial tissue that is seen in histologic sections of developing tooth and this is also the first evidence of tooth development
Dental lamina
Initiation or bud stage occurs when?
6 weeks IU
Cap stage or proliferation occurs when?
11 weeks IU
It produces the enamel
Dental organ
It generates dentin and pulp
Dental papilla
It gives rise to cementum and pdl
Dental sac
When does early bell stage or histodifferentiation happen?
14 weeks IU
It differentiates into amelosblast
Inner enamel epithelium
It differentiates into dental papilla
Peripheral cells of dental papilla
It forms the hertwig’s epithelial root sheath
Inner enamel epithelium and outer enamel epithelium
This is the stage where cells find an arrangement that ultimately dictates the final size and shape of tooth
Morphodifferentiation - Late bell stage
When does morphodifferentiation happen?
18 weeks IU
What genes induce differentiation of odontoblast
Wnt - wingless/ integrated
Runx- runt-related transcription factor
TGFB- transformation growth factor beta
What genes induce differentiation of ameloblast?
BMP- bone morphogenetic protein
FGF- fibroblast growth factor
It is the formation of tissue matrix of the tooth and accounts for the layered appearance of enamel and dentin
Apposition
It is the influx of mineral salts within the developed tissue matrix
Calcification
Where does calcification begins in enamel?
Cusp tips and incisal edges
Calcification of primary teeth (tooth and when)
A -14 weeks
D- 15.5 weeks
B- 16 weeks
C- 17 weeks
E- 18 weeks
When does emergence of tooth through the gingiva happens (nollas)
1/2 or 2/3 of root development (stage 7 and 8)
It means wearing away
Attrition
