DEVELOPMENT OF THE PERMANENT DENTITION

Question 1

1. Variability

Answer 1

More so than deciduous dentition, the

sequence is VARIABLE

Question 2

2: Gender differences

Answer 2

Girls are ahead of boys in calcification and
except for the third molars, girls are ahead of boys
by an average of 5-6 months in the eruption
pattern

Question 3

1. Timing is consistent within a dentition –

Answer 3

children who erupt any

tooth early or late tend to acquire others early or late

Question 4

2. Both sides should erupt at the

Answer 4

same time

Question 5

3. Different eruption sequences explain most frequently crowded
   teeth:

Answer 5

maxillary cuspids and mandibular second bicuspids

Question 6

Local influences which hasten permanent tooth

eruption (2)

Answer 6

1. localized pathosis:
2. if the primary tooth is extracted during active eruption of permanent tooth
   (more than 2/3 of the root formed)

Question 7

1. localized pathosis:

Answer 7

➢ periapical lesions (abscess), pulpitis and pulpotomy? of a primary molar)

Question 8

Local influences which slow permanent tooth

eruption (1)

Answer 8

When a primary tooth is extracted before active eruption of
permanent tooth (i.e. before root formation)

Question 9

• Arch width

The increases are tied to

Answer 9

alveolar
process growth (both dental
eruption and vertical process
growth)

Question 10

▪Vertical Alveolar Process Growth

2

Answer 10

▪ occurs during general growth
“spurts”
▪ different for maxilla and
mandible: divergent maxillary
process translates into more arch
width growth

Question 11

Arch width changes

3

Answer 11

• Dental Eruption
▪ wider placement of the permanent teeth
▪ apposition of alveolar bone to support these teeth will result in
increase in arch width

Question 12

Maxillary arch (3)

Answer 12

➢ increases occur during growth spurts
➢ increases occur during eruption of incisors
➢ large increase occurs during eruption of the
cuspids

Question 13

NO SIGNIFICANT INCREASES IN —
WIDTH OCCUR IN EITHER THE MAXILLA OR
MANDIBLE AFTER THE ERUPTION OF PERMANENT
CANINES

Answer 13

INTERCANINE

Question 14

Dimensional changes in the Dental Arches (3)

Answer 14

➢ changes are quite variable
➢ different for males and females
➢ different for maxillary and mandibular arches

Question 15

Arch perimeter changes
Maxillary arch (3)

Answer 15

▪ Variable(depends on pattern of tooth eruption)
▪ Not difference between sexes
▪ Factors which limit loss include greater labial angulation of incisors, greater
increases in arch width and smaller leeway space

Question 16

What about third molars? (2)

Answer 16

• Prophylactic extraction of impacted teeth is a reasonable option.
• Extraction of third molars to avoid orthodontic relapse has a weak
correlation. Association vs Correlation?