Developmental stages of tooth.

1.Tooth bud
2.Oral epithelium
3.Ectomesenchyme

Bud stage.
-Enamel organ=central polygonal cells, peripheral low columnar cells.
-Dental papilla= forming pulp and dentin.
-Dental sac= ectomesenchyme that surrounds enamel organ and dental papilla.
= forming periodontal ligament and cementum.

Cap stage.
-Cap like shaped of enamel organ.
-Due to invagination on inner surface of tooth bud result from unequal division.
-Characterized by = outer and inner enamel epithelium(OEE, IEE), stellate reticulum.
o OEE= cuboidal cells, cover the convexity of cap.
o IEE= tall columnar cells, cover the concavity of cap.

= Basement membrane separate from dental papilla.
o Stellate reticulum

= cellular network of polygonal cells between IEE n OEE,
=separated by intercellular fluidàproteinatious fluid containing albumin
=f(x)=cushion like consistency to support n protects enamel forming cells.
o Dental papilla= the condensation of ectomesenchymal cells that covered by invaginated portion of IEE.
o Dental sac= condensation of surroundings areas of dental papilla n enamel organ resulting in fibre development.

1.Dental lamina
2.Dental sac or follicle
3.Outer dental epithelium
4.Stellate reticulum
5.Inner dental epithelium
6.Dental papilla
7.Enamel cord
8.Enamel navel
9.Blood vessel
10.Enamel niche
11.Successional dental lamina

Bell stage
- Characterized by = outer and inner enamel epithelium(OEE, IEE), stellate reticulum, stratum intermedium
o OEE
- cuboidal cells
- folded before enamel formation
- capillary network dev. From dental sac between folds.
- Provide blood supply to enamel organ.
- Dental papilla develops odontoblasts-->lay down dentin before first layer of enamel matrix.
o IEE= tall columnar cells à ameloblasts.
- F(x)=Influences underlying ectomesenchymal cells of dental papilla to form odontoblasts
o Stellate reticulum
- Continuous expansion in size due to increase intercellular fluid
- Before enamel formation, it collapse to decrease distance between ameloblast and capillary network.
o stratum intermedium
- layer of squamous cells btwn IEE and stellate reticulum.
- F(x)= essential for development, formation and calcification of enamel
o Dental papilla
- Covered by enamel organ.
- Its peripheral cells develop into odontoblast
- Cuboidal --> columnar-->secrete predentin

Advanced bell stage
- Future dentinoenamel junction- forms from boundary between IEE and odontoblast
- Hertwig’s epithelial root sheath (HERS) - forms from cervical portion of enamel organ.

p/s; tahu sikit2 tentang gigi kita..huhuhu