Primary Dentition and Tooth Eruption

Question 1

What teeth are found in each quadrant of the deciduous dentition

Answer 1

2 incisors
1 canine
2 molars

Question 2

Describe the shapes of the crowns and roots of upper right central incisors

Answer 2

• Acute angle mesially
• Smooth curve distally
• Convex cingulum
• Concave lingual fossa
• Oval to circular root

Question 3

Describe the shapes of the crowns and roots of lower right central incisors

Answer 3

• Mesially forms obtuse angle from apex of root to crown
• Distally = straight line from apex of root to crown
• Slightly convex cingulum
• Slightly concave lingual fossa
• Flattened oval root

Question 4

Describe the shapes of the crowns and roots of deciduous upper right central incisors (A’s)

Answer 4

• Mesial right angle on crown
• Distal smooth curve on crown
• Convex cingulum
• Shallow lingual fossa
• mesiodistal length greater than crown height
• Oval root

Question 5

Describe the shapes of the crowns and roots of deciduous lower right central incisors (A’s)

Answer 5

• Mesial and distal = obtuse angle from apex of root to crown, distal = more obtuse
• Convex cingulum
• Slightly concave lingual fossa
• Slight labial bulge
• Flattened oval root

Question 6

Describe the shapes of the crowns and roots of deciduous upper right lateral incisors (B’s)

Answer 6

• Mesial acute angle on crown
• Distal smooth curve on crown
• Convex cingulum
• Concave lingual fossa
• Labial bulge
• Flattened root

Question 7

Describe the shapes of the crowns and roots of deciduous lower right lateral incisors (B’s)

Answer 7

• Mesial acute angle on crown
• Distal smooth curve on crown
• Mesial and distal obtuse angle from apex of root to crown
• Crown rotated towards canine
• convex cingulum
• Shallow lingual fossa
• Circular root

Question 8

Describe the shapes of the crowns and roots of upper right canines

Answer 8

• slightly convex crown mesially
• markedly convex crown distally
• Mesial slope shorter than distal slope, on crown
• convex cingulum
• Slightly concave fossa
• Wide buccal/lingual dimensions

Question 9

Describe the shapes of the crowns and roots of lower right canines

Answer 9

• crown and root in a straight line
• markedly convex
• mesial slope shorter than distal
• slightly concave lingual fossa

Question 10

Describe the shapes of the crowns and roots of deciduous upper right canines

Answer 10

• Short convex cervial curve mesially
• Long convex curve distally
• Mesial slope longer than distal
• Convex cingulum
• Shallow lingual fossa
• Curved triangular root

Question 11

Describe the shapes of the crowns and roots of deciduous lower right canines

Answer 11

• Slightly convex mesially
• convex distally
• Mesial slope shorter than distal
• Convex cingulum
• Shallow lingual fossa
• Curved triangular root

Question 12

When do the permanent and deciduous dentition develop relative to each other

Answer 12

They develop simultaneously

Question 13

Where do teeth develop within

Answer 13

Alveolar bone

Question 14

What happens to deciduous teeth before they are replaced with permanent teeth

Answer 14

Root resorption

Exfoliation (loss)

Question 15

What is classified as clinical emergence of teeth

Answer 15

When the tooth is visible in the oral cavity

Question 16

Describe what tooth eruption is

Answer 16

A process of tooth movement from within alveolar bone up to functional occlusion

Question 17

What are the 5 stages of passive and active eruption stages

Answer 17

1. Pre-eruptive movement
2. Intra-osseus
3. Mucosal penetration
4. Pre-occlusal
5. Post-occlusal movement

Question 18

Describe the active stages of tooth eruption

Answer 18

1. Intra-osseus - tooth in alveolar bone, alveolar eruption
2. Mucosal penetration - clinical/gingival emergence
3. Pre-occlusal - prior to reaching functional occlusion

Question 19

What is the dental follicle

Answer 19

A sac containing the developing tooth and its odontogenic organ.

Question 20

What does the dental follicle differentiate into

Answer 20

The periodontal ligament

Question 21

Roughly when does the first permanent tooth erupt

Answer 21

around 6 years

Question 22

Roughly when does the last of the first 28 permanent teeth erupt

Answer 22

around 13 years

Question 23

Roughly in what order do deciduous teeth erupt

Answer 23

1. Lower central and lateral incisors, upper central and lateral incisors (6-12 months)
2. Eruption of first molars (14 months)
3. Eruption of canines (18 months)
4. Eruption of second molars (24 months)

Question 24

What are the different stages of developing dentition

Answer 24

1. before any teeth have erupted
2. deciduous dentition
3. mixed dentition (early)
4. mixed dentition (ugly duckling)
5. permanent dentition

Question 25

Roughly in what order do permanent teeth erupt

Answer 25

1. lower central incisors and lower 1st molars (6yrs)
2. lower lateral incisors and upper central incisors (7yrs)
3. upper lateral incisors (8yrs)
4. pre molars (10-11yrs)
5. canines and 2nd molars (11-12yrs)
6. 3rd molars (16-20yrs)

Question 26

How do permanent mandibular incisors erupt relative to deciduous incisors

Answer 26

lingually

Question 27

What is active and passive eruption

Answer 27

Active eruption - movement of the tooth

Passive eruption - exposure of the crown by migration of the gingival attachment

Question 28

When do the first and last teeth of deciduous dentition erupt

Answer 28

1st - 6months ish

last = 2.5 yrs each

Question 29

When do permanent teeth begin to erupt relative to root growth

Answer 29

Permanent teeth begins to erupt during early root growth