quiz for rey

Question 1

Root formation

Answer 1

Begins after the outline of the crown has been established but before the full crown is calcified.

Question 2

these layers of and **** which make up the **** begin to undergo rapid mitotic division and grow deep into the underlying connective tissue – the beginning of root formation.

Answer 2

OEE

IEE

epithelial root sheath (hertwigs epithilia root sheath)

Question 3

Dentinocemental Junction

Answer 3

Some epithelial root sheath cells do not pull away and may become ameloblasts, forming small globs of enamel on the surface of the dentin.

Question 4

enamel pearls are found in

Answer 4

are found in bifurcations and trifurcations of roots.

Question 5

cementum

Answer 5

A hard, yellowish substance covering the root of the tooth.
45% to 50% inorganic hydroxyapatite crystals.
50% to 55% is organic components and water.
It is first seen at the cervical line of the tooth, also called the cementoenamel junction ( CEJ )

Question 6

acellular cementum

Answer 6

all of the cementoblasts remain on the surface rather than becoming trapped within the cementum.

Question 7

cellular cememntum

Answer 7

is more vital than acellular cementum and therefore more responsive to remodeling itself; located in apical 1/3 of the root.

Question 8

The cellular cementum at the apex of the root tends to increase in thickness with the passage of time and as a result of stress causing thickening known as

Answer 8

hypercementosis

Question 9

As the ****
forms from the middle of the layer of cells in the old ** the ends of the periodontal fibers become surrounded by *****, whose secretion hardens around the ends of the fibers, attaching them to the **

Answer 9

periodonatl membrane/ligament

dental sac

cementoblasts

cementum

Question 10

Parts of the periodontal ligament embedded in cementum are known as

Answer 10

sharpeys fiber

Question 11

are the parts of the periodontal ligament surrounded by cementum on the tooth side and alveolar bone on the opposite side in the wall of the tooth socket.

Answer 11

sharpeys fiber

Question 12

alveolar bone is

Answer 12

Is the bone of the upper or lower jaw that makes up the sockets for the teeth.

Question 13

three layers of alveolar bone

Answer 13

The layer of compact bone on the buccal or lingual surface is referred to as the cortical plate of bone. It has normal periosteum. The bone that forms the socket for the tooth is also a compact bone but does not have a normal periosteum.
This layer is called the cribriform plate or alveolar bone proper. Radiographically it is referred to as the lamina dura. The tooth socket is constantly being remodeled, and additional bone, called bundle bone, laid down on the cribriform plate. A thickened lamina dura, which can be seen in a radiograph, is caused by bundle bone being laid down on the cribriform plate and is an indication of occlusal trauma to that tooth or teeth.
Between the cortical plate and the cribriform plate is a layer of spongy or cancellous bone. Spongy bone is a bone marrow. A radiograph will only show the cribriform plate, the spongy bone and the crest of bone that joins two sockets, called the interproximal alveolar crest of bone.

Question 14

the three groups of the periodontal ligament are

Answer 14

gingival
transseptal
alveolodental fibers

Question 15

run from the cementum into the free and attached gingival area; support the gingiva.

Answer 15

gingival fibers

Question 16

run around the tooth in free gingiva and hold gingiva against the tooth.

Answer 16

circular gingival fibers

Question 17

run from the cementum of the
interproximal portion of one tooth, across the alveolar crest of bone, to the cementum of the interproximal portion of the adjacent tooth; hold the teeth in interproximal contact.

Answer 17

transseptal fibers

Question 18

run from cementum to alveolar bone

Answer 18

alveodental fibers

Question 19

runs from cementum, slightly apical to the alveolar crest of bone; helps resist horizontal movements of teeth.

Answer 19

alveolar crest group

Question 20

runs from the cementum horizontally to the alveolar crest; helps resist horizontal movement.

Answer 20

horizontal group

Question 21

runs from the cementum coronally into the alveolar bone; main fiber group for resisting occlusal stresses.

Answer 21

oblique group

Question 22

runs from the apex of the tooth into the adjacent alveolar bone; resists forces trying to pull the tooth from its socket.

Answer 22

apical group

Question 23

group- found only on multirooted teeth; runs from the alveolar crest of the bone between the roots of the tooth to adjacent cementum; resists the forces trying to remove the tooth.

Answer 23

interradicular group

Question 24

Begins as the crown starts to develop.
Eruptive movement associated with the pre-eruptive stage is of two varieties – spatial and excentric.
Spatial movement -the crown develops while the bottom of the socket fills in with bone, pushing the crown toward the surface.
Excentric or off-center growth- the crown of a tooth does

Answer 24

pre eruptive stage

Question 25

Begins with the development of the root. The tooth breaks through the mucosal layer and emerges into the oral cavity. This stage continues until the erupting teeth meet the opposing teeth. The eruptive stage tends to be occlusal and facial, more facial in the anteriors than in the posteriors.

Answer 25

eruptive stage or prefunctional eruptive stage

Question 26

Begins when the teeth come into occlusion and continues until they are lost or death occurs. Functions in several ways. First, the mandible continues to grow and increase the space between the maxilla and mandible, the teeth will continue to erupt to maintain a balance in the arches. Second, the teeth wear occlusally because of prolonged masticatory stress and wear, they will continue to erupt to maintain tooth contact. Third, because there is slight interproximal wear, there will be a slight mesial eruptive force that keeps the teeth in contact. Finally, if an opposing tooth is lost, the tooth may continue to erupt in what is generally referred to as supraeruption which can cause serious problems in the replacement of the missing tooth, because it makes it difficult to establish the normal occlusal plane.

Answer 26

post eruptive stage

Question 27

increase in root length, or root elongation, forces the tooth into the oral cavity.

Answer 27

root elongation

Question 28

alveolar bone growth, tooth development, and eruption are interdependent mechanisms.

Answer 28

alveolar bone foration and changes

Question 29

vascular pressures present enhance cellular activity but seem to have a direct eruptive role.

Answer 29

vascular pressure in dental tissues

Question 30

There are several reasons why primary teeth are retained beyond their normal time for exfoliation.

Answer 30

First, there may be no permanent successor. Second, there may be ankylosis of the primary tooth, a condition in which the alveolar crest of bone fuses in the cervical area with the cementum of a resorbing root. Last, the permanent tooth does not erupt in its normal position and therefore does not cause resorption of the primary tooth root or roots.