Tooth Development Flashcards Preview

Oral Biology (Oral Cavity) > Tooth Development > Flashcards

Flashcards in Tooth Development Deck (42)
Loading flashcards...

What is the dental lamina

- A fold in the developing oral epithelium that gives rise to tooth germs


What are the 5 stages of tooth development

1. Bud
2. Cap
3. Bell
4. Crown
5. Root


What stages of tooth development happen before mineralisation

1. Bud
2. Cap
3. Bell


Give a super brief description of what happens in the bud stage

1st condensation of mesenchyme around epithelium, characterised by appearance of tooth bud with no clear arrangement of cells


Give a super brief description of what happens in the cap stage

Enamel organ forms "cap" above the dental papilla

This stage begins once the epithelial cells proliferate into the ectomesenchyme of the jaw


Give a super brief description of what happens in the bell stage

Shape of tooth crown begins to emerge in contours of enamel organ


Give a super brief description of what happens in the crown stage

Mineralised crown tissue (dentine and enamel) deposition


Give a super brief description of what happens in the root stage

Crown formation complete, roots grow, and tooth erupts and root apex matures


What is the ectoderm

developmental germ layer that forms skin, oral epithelium, and enamel organ.


What is the mesenchyme

loose, migratory, undifferentiated cells that are important in development of many tissues.


What is the dental papilla

mesenchyme-derived part of tooth germ.


What is the enamel organ

developmental derivative of dental lamina.


What is the stellate reticulum

cellular filling of enamel organ


What happens in the bud stage of tooth development

- marked by growth of epithelium into the mesenchyme
- period of extensive proliferation and growth of the dental lamina
- dental lamina forms into tooth buds that penetrate into mesenchyme
- each tooth bud is surrounded by the mesenchyme
- buds + mesenchyme develop into tooth germ and associated tissues of the tooth


What happens in the cap stage of tooth development

1. Dental lamina expands to form cap-like structure called enamel organ, which continues to grow.
2. Part of mesenchyme is concentrated under cap as dental papilla.
3. Earliest cap stages at 11 weeks.


What happens in the bell stage of tooth development

1. Enamel organ tissues begin to differentiate.
2. Enamel organ begins to fold into shape of finished crown.
3. Dental papilla tissues begin to differentiate.
4. First reached at 14 weeks.


In the cap stage what forms the cap/enamel organ

A depression that forms in the deepest part of each tooth bud and forms the cap/enamel organ, produces the future enamel


What forms under the cap in the cap stage

A condensing mass of mesenchyme - the dental papilla - produces the future dentin and pulp tissue


What in the cap stage is the future site of the EDJ

The basement membrane that separates the enamel organ and the dental papilla


In the cap stage what does the remaining mesenchyme surrounding the enamel organ form

It condenses to form the dental sac or the dental follicle


What does the tooth germ consist of

Enamel Organ
Dental Papilla
Dental Follicle


What are the 4 types of cells in the enamel organ

1. inner enamel epithelium (IEE)
2. outer enamel epithelium (OEE)
3. stellate reticulum
4. stratum intermedium


What does the dental papilla differentiate into

1. outer cells of the dental papilla - forms the dentin secreting cells (odontoblasts)
2. central cells of the dental papilla - forms the primordial of the pulp


What is the function of OEE cells

Protective barrier during the enamel production


What do the IEE cells differentiate into



What is the shape of the stellate reticulum

Star shaped


What is the role of the stellate reticulum

supports the production of enamel and produce GAGs


What is the role of the stratum intermedium cells

Supports production of enamel


How do the cells of the stellate reticulum become star shaped

- cells in the centre of the enamel organ (enamel knot) begin to synthesize and secrete glycosaminoglycans
- this pulls water into the enamel organ
- increasing amount of fluid, forces the cells apart
- however, they remain connected via cellular processes which makes them star shaped


How can the primordia of the permanent dentition first be seen

during the cap stage the primordial appears as an extension off the developing dental lamina (site of origin = successional dental lamina)