Paediatric tooth morphology

Question 1

What are distinguishing features of the primary central incisor

Answer 1

• medial edge of the crown tends to be straighter
• root may have a slight bend going to the distal

Question 2

How can we distinguish between an upper and lower central incisor

Answer 2

• upper central incisors are more bulbous than the lower
• the lowers are more triangular and thinner
• palatal of upper has a cingulum

Question 3

What are distinguishing features of primary canines

Answer 3

medial is straighter than the distal, the distal flares out

diamond shaped

Question 4

How can we distinguish between upper primary canines and lower ones

Answer 4

• lowers are slimmer than uppers

Question 5

What are distinguishing features of upper primary first molars

Answer 5

• has a prominent tubercle on the mesiobuccal
• square shaped crown
• has an S shaped fissure

Question 6

What are distinguishing features of upper primary second molars

Answer 6

• has a transverse ridge and two buccal roots
• resembles the upper first permanent molar

Question 7

What are distinguishing features of the lower primary second molar

Answer 7

• large tubercle on the mesio-buccal

Question 8

What are distinguishing factors of lower primary second molars

Answer 8

• looks like first permanent lower molar
• 5 cusps
• smallest cusp is distalbuccal
• largest cusp is medial buccal
• has 2 roots that splay because of germs

Question 9

Why do we want anterior spacing in primary dentition

Answer 9

prevents crowding in permanent

Question 10

What is the spacing medial to the upper canine and distal to the lower called

Answer 10

primate spacing

Question 11

What is primate spacing

Answer 11

spacing mesial to upper canine and distal to lowers

Question 12

What is lee way space

Answer 12

extra mesiodistal space occupied by primary molars which are wider than the premolars that will replace them

Question 13

What is the extra mesiodistal space occupied by primary molars which are wider than the premolars that will replace them called

Answer 13

lee way space

Question 14

What are anatomical differences between the crowns of primary and permanent teeth

Answer 14

• coronal dentine is thinner on primary teeth
• enamel of primary teeth is thin but has a consistent depth unlike permanent teeth where enamel thickness varies

Question 15

What are anatomical differences in the roots of primary teeth vs permanent teeth

Answer 15

primary roots are narrower and flare to allow room for permanent

Question 16

What are anatomical differences in the pulp of primary and permanent teeth

Answer 16

primary teeth have larger pulp chambers in proportion to the crown

pulp horns extend higher occlusal