Dental Development

Question 0

At what age (in months in utero) does each primary tooth begin to calcify?

Answer 0

A: 4 months
B: 4 months
C: 4 - 5 months
D: 4 - 5 months
E: 4 - 6 months

Question 1

What is the order of calcification of the primary dentition from the first to start to the last to start?

Answer 1

A B C D E

Question 2

In what order do the primary teeth erupt?

Answer 2

A B D C E

Question 3

At what age (is months after birth) does each primary tooth erupt?

Answer 3

A: 6 - 7 months
B: 7 - 8 months
C: 18 months
D: 12 months
E: 24 - 36 months

Question 4

What is the general rule for crown completion in primary dentition in relation to its eruption date? And what are the crown completion dates for the primary dentition?

Answer 4

Half the eruption age. 
A: 3 months
B: 3 months
C: 9 months
D: 6 months
E: 12 months

Question 5

When is root formation of the primary dentition complete? And therefore at what ages should the roots be formed?

Answer 5

Root formation is complete 1 - 1.5 years after eruption.
A: 2 years
B: 2.5 years
C: 3 years
D: 2.5 years
E: 3 years

Question 6

Using plain vision in a child’s mouth, at what age should you see completion of the primary dentition?

Answer 6

3 years old

Question 7

Between the maxillary and mandibular primary dentition, which arch usually erupts first?

Answer 7

Mandibular arch

Question 8

At what age do the permanent mandibular 1 and 2 and maxillary 1 calcify?

Answer 8

3 months

Question 9

At what age do the permanent maxillary lateral incisors calcify?

Answer 9

10 months

Question 10

At what age do the permanent mandibular and maxillary canines calcify?

Answer 10

4 months

Question 11

At what age do the maxillary and mandibular 4s calcify?

Answer 11

18 months

Question 12

At what age do the mandibular and maxillary 5s calcify?

Answer 12

24 months

Question 13

At what age do all of the first permanent molars calcify?

Answer 13

At birth

Question 14

At what age do the 7s calcify?

Answer 14

2.5 years

Question 15

At what age do the 8s calcify?

Answer 15

7 - 10 years

Question 16

At 4 years old, which permanent crowns are complete?

Answer 16

1 _ _ _ _ 6 _ _

Question 17

At 5 years old, list all of the permanent crowns that are complete.

Answer 17

1 2 _ 4 _ 6 _ _

Question 18

At 3 years old, which permanent crowns are complete?

Answer 18

_ _ _ _ _ 6 _ _

Question 19

At 6 years old, which permanent crowns are complete?

Answer 19

1 2 3 4 5 6 _ _

Question 20

What is the permanent tooth whose crown completes calcification at around age 7?

Answer 20

All of the 7s

Question 21

If they are present, at what age do the 8s finish crown formation?

Answer 21

12 - 16 years

Question 22

What is the first permanent tooth to erupt and at what age does it do so?

Answer 22

First permanent molar (6) and at around age 6

Question 23

At what age do the permanent central incisors erupt?

Answer 23

Mandibular 6.5 years

Maxillary 7 years

Question 24

At what age do the permanent lateral incisors erupt?

Answer 24

Mandibular 7.5 years

Maxillary 8 years

Question 25

At what age do the permanent canines erupt?

Answer 25

Mandibular 9 - 10 years

Maxillary 11 - 12 years

Question 26

At what age to the permanent first premolars erupt?

Answer 26

10 - 12 years

Question 27

At what age to the permanent second premolars erupt?

Answer 27

11 - 12 years

Question 28

At what age do the permanent second molars erupt?

Answer 28

12 - 13 years

Question 29

At what age do the permanent third molars erupt?

Answer 29

17 - 25 years

Question 30

What is the diagram to remember the order of permanent dentition eruption?

Answer 30

6 1 2 4 5 3 7
______________________________

6 1 2 3 4 5 7

Question 31

A child comes into your practise aged 7. What mixed dentition do you expect to see?

Answer 31

6 E D C B 1 1 B C D E 6
____________________________

6 E D C _ 1 1 _ C D E 6

Question 32

A patient comes into your practise aged 9. What dentition do you expect to see in the mouth?

Answer 32

6 E D C 2 1 1 2 C D E 6
____________________________

6 E D 3 2 1 1 2 3 D E 6

Question 33

A patient comes into your practise aged 12. What dentition could you expect to see in the mouth?

Answer 33

6 E 4 C 2 1 1 2 C 4 E 6
____________________________

6 E 4 3 2 1 1 2 3 4 E 6

Question 34

Notate the lower left deciduous first molar using the Palmer system

Answer 34

___

| D

Question 35

Notate the upper right second deciduous molar using the FDI system.

Answer 35

55

Question 36

At 9 months old, what dentition do you expect to see in a baby? In what direction should these deciduous teeth have erupted?

Answer 36

_ _ _ B A A B _ _ _
_ _ _ B A A B _ _ _
Path of eruption ensures that maxillary incisors erupt labially, they may be spaced.

Question 37

What is the last permanent tooth to erupt and at what age should you expect to see a completed permanent dentition?

Answer 37

Upper canines, their timing overlaps with the upper premolar eruption path. At aged 12.

Question 38

When is permanent root formation usually complete?

Answer 38

2 - 3 years after eruption

Question 39

Neonatal teeth are a deviation from the norm. Why?

Answer 39

Deciduous central incisors usually erupt at around 6 months. If there are teeth present at birth, these will usually be lower central deciduous incisors. They are usually part of the normal sequence but occasionally can be supernumerary. If they cause an aspiration risk or are interfering with feeding/causing trauma they should be removed.

Question 40

At what age should the permanent canines be palpable buccally? If they aren’t, what could be a possible reason?

Answer 40

Age 10. If not, they could be ectopic and this requires intervention.

Question 41

What problems arise from a deviation in the timing of eruption?

Answer 41

Early loss of deciduous/primary teeth can delay or accelerate the eruption of the successor. It can also causes crowding/space loss in the permanent arch.

Question 42

What problems arise from delayed exfoliation?

Answer 42

If a primary tooth is not exfoliating when expected, it may be because the successor is missing. Parents may worry if the permanent tooth starts eruption before the primary is lost but this is common and not usually a problem… Until further failure to resorb after more permanent eruption which may lead to deciduous extraction.

Question 43

What is important in eruption sequence?

Answer 43

Eruption dates may vary but it is more important that the sequence of eruption does not vary. A tooth may not erupt at the same time as its contralateral counterpart but you should be suspicious if there is no counterpart 6 months after its full eruption.

Question 44

Is attrition, tooth surface loss and pulp exposure normal in the primary dentition?

Answer 44

Attrition is normal; significant tooth wear and pulp exposure is not. This is pathological non-carious tooth surface loss and causes should be addressed.