Anatomy of Orofacial Structures 7th Edition by Brand - Test Bank

Anatomy of Orofacial Structures 7th Edition by Brand – Test Bank

 

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Sample Questions Are Posted Below

 

Chapter 05: Development, Form, and Eruption

Test Bank

 

MULTIPLE CHOICE

 

1. Permanent mandibular central incisors are the first succedaneous teeth to erupt. The earliest visible portion of an anterior tooth is the cusp of Carabelli, the name for the lingual lobe of mandibular central incisors.

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.

 

 

ANS:   B

Although the mandibular first molars are the first permanent teeth to erupt, they are NOT succedaneous because they do NOT replace primary teeth. It is important to remember that primary molars are replaced by permanent premolars. Therefore, the first succedaneous teeth to erupt are the permanent mandibular central incisors, which replace the primary mandibular central incisors. The cusp of Carabelli is a cusp-like elevation located on the maxillary first molar and occasionally on the maxillary second molar.

 

REF:    p. 46 | p. 50

 

2. Maxillary molars have three major buccal cusps because the third buccal cusp develops from the lobe of Carabelli.

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.

 

 

ANS:   E

Maxillary molars have two major buccal cusps. The lobe, or cusp, of Carabelli is a small cusp-like elevation that develops into a tubercle. Most often seen on maxillary first molars, the cusp of Carabelli is considered a rudimentary lobe and is located on the lingual surface of the mesiolingual cusp.

 

REF:    p. 46

 

3. Roots of primary teeth resorb and dissolve because odontoblasts destroy the surrounding bone.

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.

 

 

ANS:   C

The initial statement accurately describes steps in the exfoliation of primary teeth. The reasoning provided is incorrect because odontoblasts are cells that form dentin. The cells that destroy surrounding bone during exfoliation of primary teeth are osteoclasts. Note that “blasts” are formative cells whereas “clasts” are destructive cells.

 

REF:    p. 50

 

4. Another name for the wearing away of the tooth through contact with an opposing tooth is

a.	Exfoliation
b.	Attrition
c.	Impaction
d.	Resorption

 

 

ANS:   B

Attrition is the wearing away of a tooth through contact of its functioning surfaces with an opposing tooth. Exfoliation is the process by which the roots of primary teeth are dissolved and resorbed. Impaction is a term descriptive of teeth that do not completely erupt but remain embedded in bone or soft tissue. Resorption, as it applies to exfoliation of teeth, is a phenomenon caused by osteoclastic cells, which destroy the roots of deciduous teeth. Note that “clasts” are destructive cells whereas “blasts” are formative cells.

 

REF:    p. 50

 

5. Small clumps of cells that will later form teeth are called

a.	Tooth germs
b.	Ameloblasts
c.	Lobes
d.	Tubercles

 

 

ANS:   A

Tooth germs, which later form teeth, initially develop into growth centers and become developmental lobes. Ameloblasts are cells responsible for formation of enamel. Tubercles are cusp-like elevations.

 

REF:    pp. 45-46

 

6. Bicuspid is not an accurate name for premolars. Premolars can have two, three, or four cusps.

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.

 

 

ANS:   B

The term bicuspid is reserved for teeth that actually have two cusps. Premolars can have two or three cusps. Although patterns vary, in general the maxillary first and second premolars as well as the mandibular first premolars have two cusps. The mandibular second premolars can have two or three cusps.

 

REF:    p. 45

 

7. Which choice best indicates the years of eruption for all of the premolars?

a.	8-10
b.	9-11
c.	10-12
d.	11-13

 

 

ANS:   C

The first premolars erupt at 10-11 years of age. The second premolars erupt at 10-12 years of age with eruption of the maxillary teeth preceding the mandibular. This unique pattern is the most common exception to the rule that mandibular teeth erupt prior to their maxillary counterparts.

 

REF:    pp. 49-50

 

8. Exfoliation is the process by which the roots of a deciduous tooth are pushed together by the calcification process. Resorption is the phenomenon where osteoblasts destroy the roots of primary teeth.

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.

 

 

ANS:   D

Exfoliation is the process by which the roots of a primary (deciduous) tooth are resorbed and dissolved until so little root remains that the primary tooth falls out. As a permanent tooth erupts, bone-destructive osteoclasts destroy the root of the deciduous tooth. This process is called resorption. Note that “clasts” are destructive cells whereas “blasts” are formative cells.

 

REF:    p. 50

 

9. An impacted tooth is one that has

a.	Not erupted fully
b.	No tooth germs
c.	Less cusps or roots
d.	To be extracted
e.	Both a and c

 

 

ANS:   A

Impacted teeth are those that do not completely erupt but remain embedded in bone or soft tissue. There are varying degrees of impaction.

 

REF:    p. 50

 

10. Formation of teeth can be affected by nutritional deficiencies, fever, or childhood illnesses. While trauma to the dentition may delay eruption, it does not negatively impact formation of teeth.

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.

 

 

ANS:   B

Formation of teeth can be affected by many factors including nutritional deficiencies, fever, childhood illness, and trauma to the dentition. Not only may tooth formation by altered by these factors, formation or mineralization may be stopped completely.

 

REF:    p. 47

 

11. A 6-year-old has a space maintainer on the area of the deciduous mandibular left first molar. Which permanent tooth will erupt in the space?

a.	First premolar
b.	Second premolar
c.	First molar
d.	Second molar

 

 

ANS:   A

Deciduous molars are replaced by permanent premolars. The deciduous mandibular left first molar will be replaced by the permanent mandibular left first premolar. A space maintainer is an excellent device for preserving space in the event of premature loss of a deciduous tooth.

 

REF:    p. 48

 

12. Which is the last permanent incisor to erupt?

a.	Maxillary central
b.	Maxillary lateral
c.	Mandibular central
d.	Mandibular lateral

 

 

ANS:   B

The first general rule concerning eruption is that individual mandibular teeth precede their maxillary counterparts. Eruption of central incisors precedes eruption of lateral incisors. Thus, the maxillary lateral incisor is the last permanent incisor to erupt.

 

REF:    p. 46

 

13. Edentulous refers to

a.	The final dentition period
b.	A space maintainer
c.	Absence of teeth
d.	Unerupted third molars

 

 

ANS:   C

Edentulous means that all teeth are missing. A space maintainer is an appliance utilized to preserve space for either premature loss of a deciduous tooth or loss of any tooth. Unerupted third molars are considered impacted if they remain embedded in bone or soft tissue and fail to erupt.

 

REF:    pp. 50-52

 

14. The most common exception to the rule of eruption that mandibular teeth precede eruption of maxillary teeth is the maxillary first premolar because this tooth often precedes eruption of its mandibular counterpart.

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.

 

 

ANS:   A

Eruption of the maxillary first premolar often precedes eruption of the mandibular first premolar. This is in direct contradiction to the first general rule of tooth eruption, which states that mandibular teeth usually precede the maxillary teeth.

 

REF:    p. 50

 

15. The rounded protuberances on the incisal edge of a newly erupted incisor are called

a.	Mamelons
b.	Developmental grooves
c.	Cusp tips
d.	Tooth buds
e.	Attrition

 

 

ANS:   A

Mamelons, rounded protuberances on the incisal edge of a newly erupted incisor, are incisal ridges of the three labial developmental lobes. Regarding the incorrect selections, developmental grooves separate tooth lobes and are visible on erupted teeth as grooves separating cusps. Cusp tips are the most coronal and pointed aspect of a cusp. Tooth buds, also called tooth germs, are early cellular precursors to teeth. Attrition is the wearing away of tooth surface by contact with opposing tooth surfaces.

 

REF:    p. 45 | pp. 50-51

 

16. The first deciduous teeth, the mandibular central incisors, erupt at approximately 6.5 to 7 months. The first permanent teeth, the maxillary premolars, erupt at approximately 6 years of age.

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.

 

 

ANS:   B

The first deciduous teeth are the mandibular central incisors, which erupt at approximately 6.5 to 7 months. Approximately 1 month later, the maxillary central incisors become visible. The first permanent teeth to erupt are the mandibular first molars, followed by the maxillary first molars within a few weeks. These teeth are often called the 6-year molars because they erupt at approximately 6 years of age. The maxillary premolars do not erupt until approximately 10-11 years of age.

 

REF:    p. 47 | p. 50

 

17. It is unusual for a 3-year-old child to have all twenty primary teeth because second molars do not typically erupt until 4 years of age.

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.

 

 

ANS:   E

Both the initial statement and the reason provided are incorrect because all twenty deciduous teeth typically erupt by the time a child is  years of age. The second molars, often the last teeth to erupt, are called the 2-year-old molars. Their eruption is considered a factor in the somewhat cantankerous attitude of 2-year-olds.

 

REF:    p. 47

 

MULTIPLE RESPONSE

 

1. Which of the following selections include teeth that should be present in the dentition of a 3-year-old child (select all that apply)?

a.	Primary maxillary and mandibular canines
b.	Primary maxillary and mandibular central incisors
c.	Primary maxillary molars, but NOT primary mandibular molars
d.	Primary mandibular central and lateral incisors, but NOT primary mandibular incisors
e.	Primary mandibular and maxillary premolars

 

 

ANS:   A, B

In a 3-year-old child all primary teeth should be present. Selections C and D are incorrect because they exclude primary teeth. Selection E is incorrect because the primary dentition does NOT have premolars. The primary dentition consists of twenty teeth comprised of incisors, canines, and molars.

 

REF:    pp. 47-48 | pp. 51-52

 

2. Which of the following selections include teeth that should have erupted or may be in the process of eruption in the dentition of an 8-year-old child (select all that apply)?

a.	All deciduous teeth
b.	Permanent maxillary central and lateral incisors
c.	Permanent maxillary and mandibular first molars
d.	Permanent canines

 

 

ANS:   B, C

The mixed dentition begins at about 6 years of age. The deciduous maxillary and mandibular central and lateral incisors will have been exfoliated in an 8-year-old child. At this age the central incisors of both arches should be present; the corresponding lateral incisors should be in the process of eruption. Permanent maxillary and mandibular first molars, appropriately called the 6-year molars, erupt at approximately 6 years of age. Permanent canines do not erupt until ages 9-12, with the mandibular canines preceding the maxillary.

 

REF:    p. 47 | pp. 49-50

 

3. A 15-month-old toddler would generally have (select all that apply):

a.	Central incisors
b.	Lateral incisors
c.	Canines
d.	First molars
e.	Second molars

 

 

ANS:   A, B, D

Deciduous central and lateral incisors typically erupt between  and 8 months. First molars typically erupt between 12 and 16 months. Regarding the incorrect selections, canines do not erupt until 16 to 21 months; they are followed by the second molars between the twenty-first and thirtieth months. Deciduous second molars are often called the 2-year-old molars.

 

REF:    p. 47

 

4. A 10-year-old will generally have which of the following permanent teeth (select all that apply)?

a.	Maxillary lateral incisors
b.	Maxillary canines
c.	Mandibular canines
d.	Mandibular second premolars
e.	Mandibular first molars

 

 

ANS:   A, C, E

Maxillary lateral incisors erupt at 7 to 9 years of age. The mandibular canines erupt at 9 to 10 years of age. The mandibular first molars erupt at 6 to 7 years of age. Regarding the incorrect selections, the maxillary canines do not erupt until 11 to 12 years of age. The mandibular second premolars do not erupt until 10 to 12 years of age.

 

REF:    pp. 50-52

 

TRUE/FALSE

 

1. A tooth with two cusps, such as a maxillary premolar, was formed from two lobes.

 

ANS:   F

Premolars are formed from four lobes: three facial lobes and one lingual lobe.

 

REF:    p. 45

 

2. The crypt will become the tooth socket.

 

ANS:   T

Primary and secondary teeth develop from tooth germs, which form in small holes within the bone. Crypts later become tooth sockets, which house the root of the tooth.

 

REF:    p. 45

 

3. Third molars are the most unpredictable of all teeth.

 

ANS:   T

Development of third molars is the most unpredictable of all teeth. It is highly possible for mandibular third molars to be extremely well developed, better proportioned, and larger than the first molars in the same mouth. However, they are more likely to be poorly formed and can vary from three to eight cusps. The third molars are also the most common teeth to be congenitally missing.

 

REF:    p. 46 | p. 50

 

4. Calcification of all deciduous teeth begins near the end of the sixth month in utero.

 

ANS:   F

Calcification of the primary teeth begins to by about the fourth or fifth month of fetal life. This process continues until about the third or fourth year after birth, when the deciduous roots become fully formed.

 

REF:    p. 44

 

5. A developmental groove separates one cusp from another.

 

ANS:   T

Developmental grooves separate developmental lobes from each other. Cusps, which originate from lobes, are visibly separated after eruption by developmental grooves.

 

REF:    p. 45

 

6. Third molar roots continue to calcify until about 25 years of age.

 

ANS:   T

Calcification of permanent teeth begins soon after birth and continues until about the twenty-fifth year, when roots of the third molars become calcified. The last area of any tooth to become calcified is the apex of the root.

 

REF:    p. 45