Oral Anatomy Final - Primary Dentition

Question 1

What are the functions of primary (deciduous) teeth?

Answer 1

• chewing (mastication)
• support for lips and cheeks
• formulation of speech
• maintain arch space and room for secondary teeth

Question 2

What tooth type is present in secondary dentition, but not present in primary dentition?

Answer 2

premolars

Question 3

What range of adult teeth (in universal numbers) replace maxillary primary teeth A-J?

Answer 3

4-13

Question 4

What range of adult teeth (in universal numbers) replace mandibular primary teeth K-T?

Answer 4

20-29

Question 5

What is the definition of succedaneous teeth? Of non-succedaneous teeth? Give an example of a non-succedaneous tooth.

Answer 5

Succedaneous teeth replace primary teeth.
Non-succedaneous teeth do NOT replace primary teeth because they erupt distally to the primary teeth. All of the secondary molars are examples of non-succedaneous teeth.

Question 6

When do primary teeth crowns form?

Answer 6

4-6 months in utero

Question 7

At what age are all primary teeth erupted?

Answer 7

age 2-3

Question 8

At what age are all primary roots completed?

Answer 8

approximately age 3

Question 9

Between birth and 6 months, what teeth are erupted in the mouth?

Answer 9

none

Question 10

Between 6 months and 2 years old, what teeth (in general) are erupting in the mouth?

Answer 10

primary teeth are erupting

Question 11

From 2 to 5/6 years old, what teeth (in general) are erupted in the mouth?

Answer 11

only primary teeth present

Question 12

Explain the “Rule of Three” for permanent dentition.

Answer 12

Hard tissue formation begins. After 3 years, crown formation is complete. After 3 more years, the tooth erupts. After another 3 years, the root formation is complete.

Question 13

For PRIMARY teeth, at what age are crowns completely formed?

Answer 13

6 months (10-12 months after formation begins)

Question 14

For PRIMARY teeth, at what age are roots completely formed?

Answer 14

1.5 to 3 years after emergence of the tooth

Question 15

For PERMANENT teeth, between what ages are crowns forming/calcifying?

Answer 15

from birth to 16 years old

Question 16

How many years prior to eruption are permanent crowns completed?

Answer 16

3-4 years prior to eruption

Question 17

How many years after eruption are permanent roots completed?

Answer 17

3 years after eruption

Question 18

What is the order of emergence of the primary teeth?

Answer 18

1. mandibular central incisors (6 months old)
2. other incisors
3. first molars
4. canines
5. second molars (2 years old)

Question 19

At what age do the secondary first molars erupt?

Answer 19

6 years old

Question 20

At what age do the secondary mandibular central incisors erupt?

Answer 20

6 years old

Question 21

Between what ages do the secondary incisors (not including mandibular central incisors) erupt?

Answer 21

7-9 years old

Question 22

Between what ages do the secondary mandibular canines erupt?

Answer 22

9-10 years old

Question 23

Between what ages do the secondary premolars erupt?

Answer 23

10-12 years old

Question 24

At what age do the secondary maxillary canines erupt?

Answer 24

12 years old

Question 25

At what age do the secondary second molars erupt?

Answer 25

12 years old

Question 26

When do the secondary third molars typically erupt?

Answer 26

late teens or early 20s

Question 27

In GENERAL, what arch tends to erupt first with secondary dentition?

Answer 27

usually mandibular arch erupts before maxillary

Question 28

Which teeth (primary or secondary) are generally whiter in color?

Answer 28

primary teeth

Question 29

True or false: Primary teeth have relatively long roots compared to crowns.

Answer 29

true

Question 30

Which teeth (primary or secondary) generally have thinner enamel and dentin layers (easier access to pulp)?

Answer 30

primary teeth

Question 31

In which direction do primary anterior teeth roots bend?

Answer 31

Primary anterior roots bend labially in the apical third to allow permanent teeth to have proper alignment.

Question 32

Is the primary maxillary central incisor wider incisocervically or mesiodistally?

Answer 32

The primary maxillary central incisor is wider mesiodistally. *NOTE: this is different than permanent dentition

Question 33

On which primary incisors are marginal ridges most prominent?

Answer 33

maxillary central incisors; mandibular lingual anatomy is less distinct

Question 34

On which side (mesial or distal) is the curve of the CEJ greater for primary teeth?

Answer 34

mesial (like permanent dentition)

Question 35

Which proximal contact is more cervical in primary maxillary canines?

Answer 35

mesial contact is more cervical | *NOTE: this is only true for primary maxillary canines and permanent mandibular first premolar

Question 36

Which cusp ridge is longer in primary maxillary canines?

Answer 36

mesial cusp ridge is longer | *NOTE: this is only true for primary maxillary canines and permanent maxillary first premolar

Question 37

On which arch do the primary canines have marginal ridges and lingual ridges more prominent?

Answer 37

maxillary arch (like secondary dentition)

Question 38

True or false: The crown tapers toward the cervical in primary molars.

Answer 38

FALSE. The crowns taper narrower toward the occlusal with a narrow occlusal table. *NOTE: this is different than permanent teeth

Question 39

For primary dentition, which are larger: first or second molars?

Answer 39

second molars are larger than first | *NOTE: this is different than permanent teeth

Question 40

What bulge is prominent on primary molars?

Answer 40

mesiobuccal bulge

Question 41

For a primary mandibular second molar, what buccal cusp is the widest?

Answer 41

distobuccal cusp is the widest; mesiobuccal and distal cusps are almost the same *NOTE: this is different than the permanent mandibular first molar in which the mesiobuccal cusp is the largest and distal cusp is the smallest

Question 42

What permanent teeth do primary second molars resemble?

Answer 42

permanent first molars

Question 43

What permanent teeth do primary first molars resemble?

Answer 43

none (maxillary molars sometimes look similar to a premolar, but still not truly resembling)

Question 44

What two cusps are prominent in primary maxillary first molars?

Answer 44

mesiobuccal and mesiolingual cusps

Question 45

How many cusps are present in primary mandibular first molars? Which cusp is the largest and longest?

Answer 45

4; mesiobuccal cusp is the largest and longest

Question 46

What is the shape of the groove pattern of primary maxillary first molar?

Answer 46

"H" pattern

Question 47

Between what ages does the secondary mandibular first molar erupt?

Answer 47

6-7 years old

Question 48

Between what ages does the secondary mandibular central incisors erupt?

Answer 48

6-7 years old

Question 49

Between what ages does the secondary mandibular lateral incisors erupt?

Answer 49

7-8 years old

Question 50

Between what ages does the secondary mandibular canines erupt?

Answer 50

9-10 years old

Question 51

Between what ages does the secondary mandibular first premolar erupt?

Answer 51

10-12 years old

Question 52

Between what ages does the secondary mandibular second premolar erupt?

Answer 52

11-12 years old

Question 53

Between what ages does the secondary mandibular second molar erupt?

Answer 53

11-13 years old

Question 54

Between what ages does the secondary maxillary first molar erupt?

Answer 54

6-7 years old

Question 55

Between what ages does the secondary maxillary central incisor erupt?

Answer 55

7-8 years old

Question 56

Between what ages does the secondary maxillary lateral incisors erupt?

Answer 56

8-9 years old

Question 57

Between what ages does the secondary maxillary first premolar erupt?

Answer 57

10-11 years old

Question 58

Between what ages does the secondary maxillary second premolar erupt?

Answer 58

10-12 years old

Question 59

Between what ages does the secondary maxillary canines erupt?

Answer 59

11-12 years old

Question 60

Between what ages does the secondary maxillary second molars erupt?

Answer 60

12-15 years old

Question 61

Give an example of isomorphism.

Answer 61

The primary second molars look like the secondary first molars.