Tooth Eruption and Exfoliation- Exam III

Question 1

The primary and permanent dentition develop _____ as the jaws increase in size from infancy to adolescence

Answer 1

simultaneously

Question 2

Jaws of the infant accommodate development of:

Answer 2

20 deciduous teeth

Question 3

At 4-5 years of age, the jaws accomodate:

Answer 3

20 deciduous erupted teeth and 28 developing teeth

Question 4

The mixed dentition stage occurs at ____ years of age

Answer 4

8-12 years

Question 5

Involves the concomitant exfoliation of deciduous teeth and eruption of permanent teeth

Answer 5

mixed dentition stage

Question 6

Defined as the movement of a tooth from its site of development within the alveolar process to its functional position in the oral cavity:

Answer 6

tooth eruption

Question 7

What three stages is tooth eruption divided into?

Answer 7

1. pre-eruptive phase
2. pre-functional eruptive phase
3. functional phase (post-eruptive phase)

Question 8

Pre-eruptive tooth movement results from: (3)

Answer 8

1. growth of the jaws
2. growth of tooth buds
3. remodeling of the walls of the bony crypt

Question 9

Results when there is resorption of the mesial wall with concomitant apposition of bone on the distal wall

Answer 9

mesial migration

Question 10

In the pre-eruptive phase, overtime the jaws increase in: (4)

Answer 10

1. length of jaw (anterior-posterior)
2. width of jaw (coronal plane_
3. alveolar ridge height
4. buccal-lingual width of the alveolus

Question 11

In the pre-eruptive phase, what region does crowding occur due to the tooth germs rapid growth?

Answer 11

anterior region

Question 12

In the pre-eruptive phase, as the jaws increase in length, the crowding is alleviated by migration of the teeth ____ which allows a more even distribution

Answer 12

distally

Question 13

In the pre-eruptive phase, with an increased jaw size, teh developing teeth move:

Answer 13

outward (facially) and towards the oral cavity (upward or downward)

Question 14

In the pre-eruptive phase, because of the jaw length, the permanent developing molars have _____ prior to and during eruption and achieve ____ only when the jaw length is sufficient to allow it

Answer 14

angled inclinations; vertical alignment

Question 15

What are the five components to the theories of tooth eruption:

Answer 15

1. root growth
2. vascular pressure
3. selective bone deposition and resorption
4. pulpal pressure
5. periodontal and gingival fiber ligaments

Question 16

Theories of tooth eruption:

Elongation of the roots in relation to stability of the fundus of the socket

Answer 16

root growth

Question 17

Theories of tooth eruption:

Increased hydrostatic pressures in the apical dental sac or periodontal ligament

Answer 17

vascular pressure

Question 18

Theories of tooth eruption:

Coronal bone resorption concomitant with bone apposition in the fundus area

Answer 18

selective bone deposition and resorption

Question 19

Theories of tooth eruption:

Tissue pressure differential in the pulp compared to the PDL

Answer 19

pulpal pressure

Question 20

Theories of tooth eruption:

Cells (myofibroblasts) exert traction on the tooth through the collagen network and cell-to-cell contacts

Answer 20

periodontal and gingival fiber ligaments

Question 21

Theories of tooth eruption:

Of the numerous causes of tooth eruption, the most frequently cited are:

Answer 21

1. root growth
2. alveolar bone remodeling
3. PDL formation

Question 22

Other factors that influence tooth eruption include:

Answer 22

1. PTH
2. MMPs produced by fibroblasts, osteoclasts and macrophages

Question 23

The gubernacular canal plays a role in:

Answer 23

eruptive phase

Question 24

A strand of connective tissue that contains remnants of dental lamina epithelium (derived from the succesional lamina)

Answer 24

gubernacular canal

Question 25

During the eruptive phase, the rate of eruption is not constant but vest described as a “burst of eruption” that averages about:

Answer 25

3mm every 3 months

Question 26

During the functional phase of tooth eruption and exfoliation, we see what two types of wear?

Answer 26

1. occlusal surface wear
2. proximal wear (mesial drift)

Question 27

Occurs during the functional phase, and is caused by oblique fiber groups of the PDL continually pulling the tooth into occlusion as enamel is abraded:

Answer 27

occlusal surface wear

Question 28

Apical cementum deposition also serves as a compensatory eruptive mechanism to continual:

Answer 28

occlusal abrasion

Question 29

Mesial inclination of teeth in full contact will yield an anterior force vector and when coupled with the pull of transseptal fibers, results in:

Answer 29

mesial drift

Question 30

Cell mediated tooth resorption involves the:

Answer 30

odontoclast

Question 31

The odontoclast involved in cell mediated tooth resorption during exfoliation is derived from monocytes that exit capillaries to become connective tissue _____ which in turn fuse together to form a syncytium of large multinucleated giant cells that function like an osteoclast

Answer 31

macrophages

Question 32

Odontoclasts degrade both the collagenous and non-collagenous matrix of _____ and ___ (lysosomal enzymes) and hydroxyapatite mineral phase (acids)

Answer 32

cementum and dentin

Question 33

specialized fibroblast-like cells that are thought to destroy the collagen fibers of the PDL associated with the resorbing tooth root:

Answer 33

Fibroclast

Question 34

Fibroclasts are thought to destroy the:

Answer 34

collagen fibers of the PDL

Question 35

The finding of apoptotic cell death in the resorbing PDL suggests that shedding of teeth is:

Answer 35

a programmed event