Deck 21: Root Formation and Attachment Apparatus

Question 1

Sharpey's fibers are part of the cementum.They are embedded in alveolar bone.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Answer 1

C
Sharpey's fibers are the ends of the periodontal ligament and are embedded in cementum lying perpendicular to its surface.

Question 2

Each of the following are classified as alveolodental fibers EXCEPT one.Which one is the EXCEPTION?

A) Alveolar crest fibers
B) Horizontal fibers
C) Circular gingival fibers
D) Oblique fibers
E) Apical fibers

Answer 2

C
The circular gingival fibers are classified as gingival fibers.They run from the cementum into the free and attached gingival areas and tend to support the gingiva.The remaining selections are groups of alveolodental fibers that run in various directions from the cementum to the alveolar bone.

Question 3

The alveolar bone that forms the tooth socket has a normal periosteum because this bone contains numerous holes that allow for passage of blood vessels.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct,but the reason is NOT correct.
D) The statement is NOT correct,but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Answer 3

D
The periosteum of bone that forms the tooth socket is considered atypical because it contains holes that enable the passage of blood vessels.The periosteum is a membrane that lines the outer surface of all bones,except at the joints of long bones.

Question 4

By definition,alveolar bone or alveolar process is bone of the upper or lower jaw that comprises the lamina dura for teeth.Bone originates from the mesoderm.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 5

The compact bone that is perforated in many places is the

A) cortical plate
B) cribriform plate
C) bundle bone
D) cancellous bone

Question 6

Development of the dentinocemental junction (DCJ)involves newly formed odontoblasts and cementoblasts.The root sheath must separate from the dentinal surface to establish the dentinocemental junction (DCJ).

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 7

During the bell stage of root development the cervical loop is located at the deepest part of enamel organ.The cervical loop and the epithelial diaphragm guide the shape and number of roots.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 8

Bone undergoes a remodeling process whereas cementum does not because the metabolic rate of bone is lower than that of cementum.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct,but the reason is NOT correct.
D) The statement is NOT correct,but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 9

Acellular cementum contains trapped cementoblasts because they remain in the matrix after secretion.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct,but the reason is NOT correct.
D) The statement is NOT correct,but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 10

The parts of the periodontal ligament embedded in cementum are known as cementocytes.The periodontal fibers surrounded by alveolar bone on the other side of the tooth socket are known as Sharpey's fibers.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 11

Osteoclasts can resorb bone,cementum,and dentin because their ability to resorb tissues is not specific to any one of these tissues.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct,but the reason is NOT correct.
D) The statement is NOT correct,but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 12

Root formation begins at the cementoenamel junction (CEJ)and proceeds to the root apex.During this process,the epithelial root sheath becomes the epithelial diaphragm.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 13

The main fiber group for resisting occlusal stress is the

A) interradicular
B) apical
C) horizontal
D) oblique

Question 14

Which of the following indicates occlusal trauma?

A) A thickened lamina dura
B) A layer of spongy bone
C) Pointed (or pyramidal-shaped)interproximal alveolar bone
D) Sharpey's fibers in the alveolar bone

Question 15

Root sheath cells that remain in the periodontal space are called epithelial rest cells.If they later divide they form epithelial rests of Malassez.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 16

The outer layer of cementum is lined with cementoblasts.Cementum has limited ability to form throughout adulthood.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 17

Immediately prior to root formation,the point where layers of outer enamel epithelium (OEE)meet inner enamel epithelium (IEE)is known as the cervical loop.This point is located at the most superficial point of enamel organ.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 18

Which is the most common relationship of the cementum to enamel?

A) Cementum meets enamel at a definite point or junction.
B) The cementum and enamel do not meet,exposing a portion of dentin.
C) The cementum overlaps enamel.
D) Enamel overlaps the cementum.

Question 19

Bone reacts more favorably to stress than cementum because bone has a higher inorganic content.

A) Both the statement and the reason are correct and related.
B) Both the statement and the reason are correct but are NOT related.
C) The statement is correct,but the reason is NOT correct.
D) The statement is NOT correct,but the reason is correct.
E) NEITHER the statement NOR the reason is correct.

Question 20

Each of the following defects can occur during or after the breakup of the epithelial root sheath EXCEPT one.Which one is the EXCEPTION?

A) Periodontal cysts
B) Accessory root canals
C) Hypercementosis
D) Enamel pearls
E) Epithelial rests of Malassez

Question 21

When a tooth is moved orthodontically,all of the following should occur EXCEPT one.Which one is the EXCEPTION?

A) Tension on periodontal fibers
B) Bone resorption
C) Bone deposition
D) Cementum regeneration

Question 22

The epithelial diaphragm is parallel to the root sheath.

Question 23

The periodontal ligament develops from the mesodermal cells of the dental sac.

Question 24

In the two cross-sectional views of alveolar bone depicted below,structure "b" illustrates the

A) cribriform plate
B) spongy bone
C) cortical plate

Question 25

In the two cross-sectional views of alveolar bone depicted below,structure "c" illustrates the

A) spongy bone
B) cribriform plate
C) cortical plate

Question 26

The epithelial root sheath is between the dental papilla and the dental sac in early root development.

Question 27

The organic components in cementum are (Select all that apply. )

A) mucopolysaccharides
B) hydroxyapatite crystals
C) collagen fibers
D) mineral salts
E) water

Question 28

The transseptal fibers run from the cementum into the free and attached gingival area.The alveolodental fibers run from the cementum to the alveolar bone.

A) Both statements are true.
B) The first statement is true;the second statement is false.
C) The first statement is false;the second statement is true.
D) Both statements are false.

Question 29

Which of the following sensations can the nerves of the periodontal fibers transmit (Select all that apply. )?

A) Pain
B) Heat
C) Cold
D) Pressure

Question 30

In the two cross-sectional views of alveolar bone depicted below,structure "a" illustrates the

A) cribriform plate
B) cortical plate
C) spongy bone

Question 31

Enamel pearls (Select all that apply. )

A) are formed by cementocytes
B) are usually found in root furcations
C) are small elevators of enamel
D) dissolve after root completion
E) often cause periodontal cysts

Question 32

The cortical plate is typically compact bone with an atypical periosteum.

Question 33

Root formation begins after the full crown has been calcified.