Deck 11: Root Morphology

Question 1

An 11-year-old boy, Ronald, has an overjet and is being treated by an orthodontist. At a routine appointment, Ronald mentions that he feels some pressure in the area of his maxillary anterior incisors and asks if this is unusual. The orthodontist examines Ronald, makes some adjustments to his appliance, and reviews his radiographs. He informs Ronald that he is pleased with the movement of his teeth and that he may feel occasional pressure throughout treatment. Which factors contribute to forming new bone (select all that apply)?

A) PDL tension/compression
B) Sustained orthodontic force
C) Osteoclastic activity
D) Osteoblastic activity
E)Not of above

Answer 1

PDL tension/compression
Sustained orthodontic force
Osteoclastic activity
Osteoblastic activity

Question 2

Cementum formed during hypercementosis is different from the cementum lining the root because this newly formed product can continue to grow and add on to itself.

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 2

A
Hypercementosis is a process of extreme overproduction of cementum. Occurring at the apical third of the root, this new product is quite different from the more typical cementum lining the surface of the root. The primary difference is that cementum formed during hypercementoma can continue to grow. Also pertinent, it is called cellular cementum because it traps cementoblasts, the cells that form cementum.

Question 3

During hypercementosis, excess cementum is deposited

A) Along the CEJ
B) Irregularly, throughout the root surface
C) At the dentinocemental junction
D) At the apex of the root

Answer 3

D
During hypercementosis, a process of extreme excess cementum production, a formation called a cementoma is deposited at the apex of the root. This process is usually associated with bone destruction and/or trauma. The newly formed excess cementum is different from the rest that lines the root.

Question 4

An 11-year-old boy, Ronald, has an overjet and is being treated by an orthodontist. At a routine appointment, Ronald mentions that he feels some pressure in the area of his maxillary anterior incisors and asks if this is unusual. The orthodontist examines Ronald, makes some adjustments to his appliance, and reviews his radiographs. He informs Ronald that he is pleased with the movement of his teeth and that he may feel occasional pressure throughout treatment. In Ronald's case, each of the following radiographic findings is considered normal during orthodontic treatment EXCEPT one. Which one is the EXCEPTION?

A) Bone remodeling
B) Widening of the PDL
C) Bone resorption
D) Root resorption

Question 5

Root pain due to exposed dentin is caused by gingival recession. Exposed spots of dentin can stimulate pulpal nerves through the cementoenamel junction (CEJ).

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

Question 6

Mandibular premolars typically have two pulp canals. Maxillary first premolars are more likely than maxillary second premolars to have two pulp canals.

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

Question 7

Orthodontics requires a sustained pressure to move teeth to a new location. Osteoblasts respond to the new location by forming new bone.

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

Question 8

Each of the following root characteristics provides significant resistance to displacement from traumatic forces EXCEPT one. Which one is the EXCEPTION?

A) Root grooves
B) Root concavities
C) A short, smooth root
D) Multiple roots

Question 9

The figure below shows a mesial view (A) and a distal view (B) of a linguobuccal section. Identify the tooth.

A) Mandibular first premolar
B) Mandibular second premolar
C) Mandibular first molar
D) Mandibular second molar

Question 10

Pain within the root (root pain) can be elicited by which of the following (select all that apply)?

A) Root decay
B) Root resorption
C) Secondary dentin
D) Dehydration
E) Reparative dentin

Question 11

Which of the following best describes the root canal opening(s) in the figure below?

A) Accessory root canals
B) One main and one accessory root canal
C) Two apical root canals

Question 12

A slight amount of mobility is not considered normal. Orthodontics can help with bone remodeling that can prevent even slight tooth mobility.

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

Question 13

Pressure and temperature responses are elicited by all of the following EXCEPT one. Which one is the EXCEPTION?

A) Bone
B) Periodontal ligament
C) Gingiva
D) Pulp tissue

Question 14

Root canal therapy in third molars is considered very unpredictable because the tooth is located so far distally in the mouth.

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 15

A patient who has sensitivity in the mandibular anterior area due to abrasion is interested in having her teeth bleached. Which factor could contribute to her sensitivity?

A) Discolored teeth
B) Thin, uneven cementum
C) Root canal treatment on mandibular central incisors
D) Slight mobility

Question 16

Teeth with curved roots afford resistance to apical and distal forces but are vulnerable to occlusal forces. Roots with triangular cross section are particularly vulnerable to lateral displacement.

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

Question 17

Each of the following teeth frequently has two roots EXCEPT one. Which one is the EXCEPTION?

A) Maxillary first premolar
B) Maxillary second premolar
C) Mandibular first molar
D) Mandibular second molar

Question 18

Maxillary molar root trifurcations are located on each of the following surfaces EXCEPT one. Which one is the EXCEPTION?

A) Mesial
B) Distal
C) Lingual
D) Buccal

Question 19

Each of the following is a characteristic of the periodontal ligament EXCEPT one. Which one is the EXCEPTION?

A) Capable of regeneration
B) Capable of compression
C) Provides tension
D) Provides support

Question 20

Blood vessels traveling through the apical foramen support nerves and odontoblasts because the blood supply enables delivery of essential nutrients as well as removal of harmful products.

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 21

Which of the following travel through the apical foramen (select all that apply)?

A) Nerves
B) Enamel pearls
C) Blood vessels
D) Nutrients
E) Lymphatic vessels

Question 22

The cementum covering the root is thick and smooth when first formed.

Question 23

If there are two pulp canals in a root, there could be one or two openings in the root.

Question 24

Dentin tubules can carry a stimulus from the root surface to the nerves in the pulp canal.

Question 25

Root pain always means that dental caries is present.

Question 26

Mandibular second molars often have two canals in each root.