Lecture 4

Question 1

variability of perm tooth eruption sequence

Answer 1

More so than deciduous dentition,
the sequence is VARIABLE

Question 2

sex differences of perm tooth eruption

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 months in eruption

Question 3

can there be difference in eruption times R vs L?

Answer 3

yes can differ slightyl if a lot may not be ideal

Question 4

perm max eruption time in years

Answer 4

Question 5

perm max eruption sequence

Answer 5

Question 6

perm man eruption times

Answer 6

Question 7

perm man eruption sequence

Answer 7

Question 8

timing of permanent eruption

Answer 8

1. Timing is consistent within a dentition –children who erupt any tooth early or late tend to acquire others early or late
2. Both sides should erupt at the same time
3. Different eruption sequences explain most frequently crowded teeth: maxillary cuspids and mandibular second bicuspids

Question 9

Local influences which hasten permanent tooth
eruption

Answer 9

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

Question 10

what can be done here

Answer 10

may do extractions but R side would likely also require space maintence

Question 11

Local influences which slow permanent tooth
eruption

Answer 11

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

Question 12

If extraction must be preformed with a perm tooth root not 2/3 formed what should you do?

Answer 12

space maintenence

Question 13

arch width changes tied to?

Answer 13

The increases are tied to alveolar process growth (both dental
eruption and vertical process growth)

Question 14

▪Vertical Alveolar Process Growth

Answer 14

▪occurs during general growth “spurts”
▪different for maxilla and mandible: divergent maxillary
process translates into more arch width growth
man teeth come in at an angle and may lose space

Question 15

how can eruption increase arch width

Answer 15

▪ wider placement of the permanent teeth
▪ apposition of alveolar bone to support these teeth will result in increasde in arch width

Question 16

Maxillary arch increases

Answer 16

➢increases occur during growth spurts
➢increases occur during eruption of incisors
➢large increase occurs during eruption of the cuspids
from about 8-11, avg increase of 4mm

Question 17

max arch decreases?

Answer 17

can be some lost at 11-12, very little

Question 18

when observing moderately crowded teeth, what should you do first?

Answer 18

trace the arch form, examine if there is space to alter intercanine/molar distance

Question 19

Arch perimeter changes of Maxillary arch

variation? sexes? what limits loss?

Answer 19

▪ 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