Lecture 3 Tooth Development Eruption & Shedding

10/22/26 lecture, had quiz 2, test 1 next week

In which week(s) of prenatal development does the BUD stage occur?

8

The bud stage is: extensive _____ of the _____ _____ into buds.

proliferation, dental lamina

Define proliferation.

controlled cellular growth

How many buds are there on each max/mand arch?

10

Give blue arrow.

dental lamina

Give pink arrow.

oral epithelium

Give green arrow.

tooth bud

Give orange arrow.

ectomesenchyme

In which week(s) of prenatal development does the CAP stage occur?

9-10

The bud stage continues ______ and the cells _______.

proliferation, differentiate

The tooth germ develops in the cap stage, meaning the _____ of the tooth.

primordium

Give the 3 things that make up tooth germ:

enamel organ, dental papilla, dental sac

The enamel ORGAN is the formation of the tooth ____ in a _____ shape with a _____ depression.

bud, cap, central

What tissue makes up dental papilla? Give the location inside enamel organ.

ectomesenchyme, concavity

What tissue makes up the dental sac? Give the location inside the enamel organ.

ectomesenchyme, outside

Give green.

primordium

Give pink.

enamel knot

Give blue.

enamel organ

Give purple.

dental papilla

Give black indicator, bottom right.

dental sac

What do the blue, purple, and black indicators make up?

tooth germ

What are succedeaneous teeth?

replace baby teeth

What is successional dental lamina?

dental lamina extends into ectomesenchyme (will form succedanenous permanent teeth)

What teeth are nonsuccedaneous?

permanent molars

Nonsuccedaneous permanent teeth develop from buds that grow off an extension of the primary _____ _____ _____ ______.

second molars, dental lamina

In which week(s) of prenatal development does the BELL stage occur?

11-12

The bell stage is the ongoing process of ______, _______, and _______.

proliferation, differentiation, morphogenesis

How many types of cell layers form during the bell stage? Where are they?

4, enamel organ

Give the 4 cell layers formed in the BELL stage.

inner EE, outer EE, stellate reticulum, stratum intermedium (EE = enamel epithelium)

Which layer serves as a protective barrier for the enamel organ? It will outline the shape of the future organ.

outer enamel epithelium

What will the inner enamel epithelium differentiate into?

ameloblasts

What will the ameloblasts form?

enamel matrix

What will the OUTER cells of dental papilla layer differentiate into?

odontoblasts

What will the odontoblasts form?

dentin matrix

What will the CENTRAL mesenchymal cells of the dental papilla layer differentiate into?

pulp tissue

What are the final stages of odontogenesis?

apposition and maturation

The apposition stage is also known as the ______ stage.

secretory

The ______, ______, and _____ are secreted during APPOSITION until the crown is complete.

enamel, dentin, cementum

What happens to the hard dental tissue during the maturation stage?

matrices fully mineralize

Give the order of tooth development.

initiation, bud, cap, bell, apposition and maturation

What embryonic tissues are responsible for ODONTOGENESIS?

ectoderm, mesenchyme

What is mesenchyme made of? Give what it will develop into.

embryonic CT, dentin cementum pulp

What is ectoderm made of? Give what it will develop into.

embryonic epithelium, enamel

What is the boundary between mesenchyme and epithelium?

basal lamina

What tissue initiates odontogenesis? It is the first communication.

mesenchyme

During apposition, many_______ occur between the ectodermal tissue of the enamel organ and mesenchymal tissue of the dental papilla and dental sac.

These interactions are necessary for the production of enamel, dentin, and cementum.

inductions

Which cells are involved in cytodifferentiation?

odontoblasts, ameloblasts

Give the first step of cytodifferentiation.

IEE cells stop dividing (morpho differentiation is complete)

How do the cells grow in the second step of cytodifferentiation? The nuclei will move AWAY from the _____ _____.

tall, basal lamina

Give the term for the nuclei moving to the part of the cell AWAY from the basal lamina. (step 2 of cytodiff)

polarity

What cell is involved in step 3 of cytodifferentiation?

pre-ameloblasts

In step 3 (cytodifferentiation) the preameloblasts are involved, they develop _____ _______ organelles.

protein synthesis

In step 4 (ctyodifferentiation) the future ______ touch the basal lamina, meaning that the critical ______ occurs for ________.

odontoblasts, communication, cytodifferentiation

During root development, the outer and inner enamel epithelium layers form…

Hertwigs epithelial root sheath

What are the 2 functions of the Hertwig Epithelial Root Sheath?

root shape, induction of root dentin

What is responsible for root development?

cervical loop

What is the most cervical part of the enamel organ?

cervical loop

The tooth is forming from the _____ to the _____.

crown, root

What is produced when the Hertwig Epithelial Root Sheath disintegrates?

epithelial rests of Malassez

Where are the Epithelial Rests of Malassez located (ERM)?

PDL surrounding root

Cementum is deposited ______ throughout the functional life of the tooth.

continuously

What kind of eruption is the vertical movement of the tooth?

active

What kind of eruption occurs when the gum recedes but the tooth is not actually moving?

passive

What is this image showing?

hyper eruption

Give the 3 phases of tooth eruption.

pre-eruptive, prefunctional, functional

Which phase of tooth eruption is involved with the bony crypts of teeth?

pre-eruptive

Molars have no primary predecessor; their enamel organs develop from….

dental lamina of primary 2nd molars

Initially, primary and secondary teeth share the same:

bony crypt

Give the term for this definition: loss of the primary dentition by physiologic resorption of the roots, the loss of the bony support as well as removal of connective tissue, epithelial cells and the PDL.

shedding

The tooth germ develops into…