Development of the Permanent Dentition Part 1

Question 1

what is the variability of the permanent dentition

Answer 1

more than the deciduous
- highly variable

Question 2

what are the sex differences in perm dentition

Answer 2

girls are ahead of boys in calcification except for 3rd molars
- girls are ahead of boys by an avergae of 5 months in eruption

Question 3

what is the emergence of the mandibular arch

Answer 3

• first molar: 6-7 years
• central incisor: 6-7 years
• LI: 7-8 years
• canine: 9-10 years
  -first premolar” 10-12 years
• second premolar: 11-12 years
• second molar: 11-13 years
• third molar: 17-21 years

Question 4

what is the emergence of the maxillary arch

Answer 4

• first molar: 6-7 years
• CI: 7-8 years
  -LI: 8-9 years
• first premolar: 10-11 years
• second premolar: 10-12 years
• canine: 11-12 years
• second molar: 12-13 years
• third molar: 17-21

Question 5

is the sequence of emergence between maxillary and mandibulr arch the same

Answer 5

no

Question 6

timing is consistent within a dentition meaning:

Answer 6

children who erupt any tooth early or late tend to acquire others early or late

Question 7

both sides should erupt at the:

Answer 7

same time

Question 8

what are the most frequentyl crowded teeth

Answer 8

maxillary cuspids and mandibular second bicuspids

Question 9

what explains most frequently crowded teeth

Answer 9

different eruption sequences

Question 10

what are the local influences that accelerate permanent tooth eruption

Answer 10

if the primary tooth is extracting during active eruption of the permanent tooth ( more than 2/3 of the root formed)

Question 11

what are the local influences that slow permanent tooth eruption

Answer 11

• when a primary tooth is extracted before active eruption of permanent tooth (before root formation)

Question 12

arch width increases are tied to:

Answer 12

alveolar process growth - both dental eruption and vertical process growth

Question 13

describe vertical alveolar process growth

Answer 13

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

Question 14

what makes arch width increase

Answer 14

• dental eruption
• wider placement of the permanent teeth
• apposition of alveolar bone to support these teeth will result in increase in arch width

Question 15

describe the increase in growth of the maxillary arch

Answer 15

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

Question 16

describe arch perimeter changes in the maxillary arch

Answer 16

• variable depending on the pattern of tooth eruption
• not different between the sexes

Question 17

what are the factors that limit maxillary arch perimeter loss

Answer 17

-greater labial angulation of incisors
- greater increases in arch width and smaller leeway space

Question 18

prophylactic extraction of impacted teeth/third molars is a ______

Answer 18

reasonable option

Question 19

extraction of third molars to avoid orthodontic relapse has a:

Answer 19

weak correlation