Eruption and Shedding

Question 1

TERM – the movements a tooth makes to attain and maintain its position in the jaw

**From the tooth’s formative stages wintin the jaws to its functional stage in the oral cavity

Answer 1

Eruption

Question 2

True or False?

A tooth will move all directions during eruption except apically

Answer 2

True

Question 3

Name the 3 stages of tooth eruption

1.

2.

3.

Answer 3

1. Pre-emergence
2. Pre-functional
3. Functional

Question 4

Name the MAIN direction of tooth movement in each eruption stage

1. Pre-emergence
2. Pre-functional
3. Functional

Answer 4

1. Pre-emergence —— FACIALLY
2. Pre-functional —– OCCLUSALLY
3. Functional —– MESIALLY

Question 5

A tooth will continue to erupt until it reaches the ___________ __________

Answer 5

Occlusal Plane

Question 6

Review: Name the 4 stages leading to the enamel organ

Answer 6

1. Dental Lamina
2. Bud
3. Cap
4. Bell

Question 7

During the pre-emergence stage, cells will concentrate at the apical end of the tooth germ called the ______ ______

Answer 7

Follicle Sac

Question 8

After enamel is complete, 4 cell layers of enamel organ become 1 _____ _____ _____

Answer 8

Reduced Enamel Epithelium

Question 9

What is the function of the REE?

Answer 9

Protects enamel during eruption

Question 10

The cervial loop is where the outer and inner layers of enamel organ come together and form 2 _____ _____ ____ _____

Answer 10

Hertwig’s Epithelial Rooth Sheaths

Question 11

The REE is attached to the enamel surface by a ______ _____

Answer 11

Basal Lamina

Question 12

The REE is known as the last secretion of ______

Answer 12

Ameloblasts

Question 13

Herwig’s epithelial rooth sheath determines 2 things:

1.

2.

Answer 13

1. # root canals (not roots)
2. Root dentin outline

Question 14

True or False

Pre-emergence stage begins after root formation

Answer 14

FALSE

Pre-emergence stage begins BEFORE root formation

Question 15

At what stage are the # of root canals determined?

Answer 15

Pre-emergence stage

Question 16

Mandibular first molars have ____ root canals in the MESIAL root

Mandibular canines also can have ____ root canals in their single root

Answer 16

2

2

Question 17

3 types of cells that differentiate during the pre-emergence stage

Answer 17

1. Ameloblasts
2. Odontoblasts
3. Fibroblasts

Question 18

At what stage does crown dentin first appear?

Answer 18

Pre-emergence

Question 19

At what stage does the pulp chamber occur?

Answer 19

Pre-emergence

Question 20

When is the DEJ estabilished?

Answer 20

Pre-emergence

Question 21

What type of cells are NOT present during the pre-emergence stage

Answer 21

Cementoblasts

Question 22

Bone ________ occurs during the pre-emergence stage

Answer 22

Remodeling

Question 23

Fate of the Hetwig’s Epithelial Root Sheath Cells

1. Diaphragm Stage
2. Sheath elongation
3. Root Dentin Formation

Answer 23

1. Diaphragm stage – number or RC’s determined; tooth erupts occlusally
2. Sheath elongates – determines the root dentin outline – diaphragm stays relatively at the same level
3. Rooth dentin forms – sheath breaks up; cementum forms on exposed dentin…. continues apically intil th eroothdentin outline is complete

Question 24

TERM – remanents of epithelial cells from Herwig’s rooth sheath in the PDL (during pre-functional stage)

They surround the tooth as part of the PDL

Answer 24

Epithelial Rest of Malassez

Question 25

During the \_\_\_\_-\_\_\_\_\_\_ stage, the **merged** **oral epithelium** and the **reduced enamel epithelium** undergo cell death

Answer 25

Pre-functional Stage

Question 26

What is the most painful stage of tooth eruption and why?

Answer 26

Pre-functional stage (babies teething) The inflammation and infection is responsible for this pain! Not necessarily the eruption of the teeth.

Question 27

During the pre-functional stage, the merged oral epithelium and reduced enamel epithelium undergo _____ \_\_\_\_\_ This is because of lack of ____ \_\_\_\_\_ to transport nutrients All because of the pressure the erupting teeth are putting on the overlying oral tissue

Answer 27

Cell Death Blood vessels

Question 28

Once the crown of the tooth has made its entry into the oral cavity, the **reduced enamel epithelium** now becomes ---?

Answer 28

Junctional Epithelium

Question 29

At what spot on the tooth does the juntional epithelium typically stop at during **pre-functional** stage

Answer 29

CEJ

Question 30

What attaches the juntional epithelium to the tooth surface?

Answer 30

Basal lamina

Question 31

The pre-functional stage begins with the start of ______ formation

Answer 31

Dentin

Question 32

What "breaks up" during the pre-functional stage?

Answer 32

Herwig's Epithelial Root Sheath

Question 33

Differentiation of cementoblasts & cementogenesis occurs during the \_\_\_\_-\_\_\_\_\_ stage

Answer 33

pre-functional stage

Question 34

How are the fibers of the PDL arranged?

Answer 34

Obliquely -- NOT functionally arranged in groups

Question 35

When does the pre-functional stage end?

Answer 35

When the erupting tooth reaches the occlusal plane

Question 36

Functional stage: Starts? Ends?

Answer 36

Starts -- at the occlusal plane Ends -- continues throughout life

Question 37

During the functional stage, the main movement is \_\_\_\_? This leads to anterior teeth crowding

Answer 37

Mesially (mesial-drift)

Question 38

The attachment of the juntional epithelium chages during the ______ stage Most likely attaching to the ________ later in life

Answer 38

Functional Cementum

Question 39

**Functional arrangement** of fiber bundles of the PDL occurs during which stage?

Answer 39

Functional

Question 40

What are changes that can occur during functional eruption?

Answer 40

1. Attrition 2. Dead tracts 3. Reparative Dentin (3\*) 4. Continued dentin formation (internally) 5. Reduced pulp tissue volume 6. Ectopic Mineralization

Question 41

True or False? A 30 year old's mandible will be the same size as an 85 year old's mandible

Answer 41

FALSE Also ... Bone is lost when teeth are lost

Question 42

Maintenance of teh Alveolar Process (remodeled bone crypt) occurs during the _______ stage

Answer 42

Functional

Question 43

TERM -- occurs between the junctional epithelium and adjacent connective tissue (lamina propria)

Answer 43

Reciprical Induction

Question 44

What stage classifies a succedaneous tooth under a primary tooth that is in its functional stage?

Answer 44

Pre-emergence

Question 45

What stage classification would a 6yr old's 1st molars be in?

Answer 45

Pre-functional (non-succedaneous)

Question 46

What stage would a 6yr old's 2nd molar be in?

Answer 46

Pre-emerging

Question 47

TERM -- the physiologic elimination of primary teeth caused by the resorptive action of odontoclasts

Answer 47

Shedding

Question 48

Odontoclasts originate in the ______ \_\_\_\_ and are conveyed to the activity site via _____ \_\_\_\_\_\_.

Answer 48

Bone Marrow Blood Vessels

Question 49

Odontoblasts resorb what 3 tooth tissues?

Answer 49

1. Enamel 2. Dentin 3. Cementum NOT PULP

Question 50

In order for a permanent central incisor to \_\_\_\_\_\_, the ______ of the primary incisor must occur

Answer 50

Erupt Shedding

Question 51

You examine a palatal view of a 5yr old's skull, what are these tiny holes?

Answer 51

Gubernaculum Canals

Question 52

What does the gubernculum canal contain?

Answer 52

Gubernaculum Ligament

Question 53

TERM -- gubernaculum ligament passes thru the gubernaculum canal and attaches to _______ of succedaneous teeth

Answer 53

Dental Follicle

Question 54

What are thought to help guide succedaneous teeth into the oral cavity?

Answer 54

Gubernaculum Ligaments