Tooth eruption

Question 1

What are the three stages of tooth eruption?

Answer 1

pre eruption: crown is forming and dentinal lamina
eruption: as the root forms the tooth begins to erupt
post eruption: when the teeth move into occlusion

Question 2

What are the four theories of tooth eruption?

Answer 2

1. development of the root causes the tooth to be pushed into the oral cavity
2. growth of the pulp causes expansion of the tooth and apical propulsion causes eruption
3. bone deposition in the alveolar crypt forces tooth eruption
4. Periodontal ligament force causes teeth to be thrust into the oral cavity.
   the 4th seems to be the most plausible scenario, all may play some role.

Question 3

What process results in exfoliation of deciduous teeth?

Answer 3

pressure of the crown of the erupting adult tooth and contact of the OEE of the permanent dentition on the deciduous root causes root resorption in the deciduous tooth.

Question 4

What four possible causes are considered with persistent deciduous teeth

Answer 4

1. Failure of a successional bud to form.
2. Ankylosisof the deciduous tooth to the alevolar bone during resorption
3. Malposition of the teeth such that the erupting adult crown fails to make contact with the root of the deciduous tooth and root resorption fails
4. Hormonal influences which alter development through altered growth or metabolism.