Comparison Of Deciduous and Permanent Dentition

Question 1

How do the crowns of primary central incisors compare to their permanent counterparts?

Answer 1

Primary incisors are smaller in proportion

Question 2

How do the crowns of primary molars compare to their permanent counterparts?

Answer 2

Primary molars are wider mesiodistally than the permanent premolars which take their place
Primary molar crowns are more bulbous

Question 3

How does colour differ between primary and permanent teeth

Answer 3

Primary teeth are usually whiter in colour

Question 4

How do the roots of primary teeth compare to their permanent counterparts?

Answer 4

Roots of primary teeth tend to be narrower

Question 5

How do the roots of primary molars compare to their permanent counterparts?

Answer 5

Roots of primary molars are longer and more slender

Roots also tend to flare apical to allow room in between for the developing permanent crowns

Question 6

How do the pulp chambers of primary teeth compare to permanent teeth?

Answer 6

Pulp chambers in the primary dentition are relatively large in proportion to the crowns that surround them

Question 7

How do the pulp horns of primary teeth compare to permanent teeth?

Answer 7

Pulp horns of primary teeth extend high occlusally, placing them closer to the enamel than the pulp horns of permanent teeth - hence pulpal exposure on cavity prep more likely

Question 8

How do the root canals of primary teeth compare to permanent teeth

Answer 8

Primary root canals tend to be ribbon shaped with multiple interconnecting and accessory canals
Clinically impossible to clean completely

Question 9

How does the dentine of primary teeth compare to the permanent teeth?

Answer 9

The thickness of the coronal dentine is much thinner than in permanent dentition

Question 10

How does the enamel of primary teeth compare to the permanent teeth

Answer 10

The enamel of the primary teeth is relatively thin and has a consistent depth

Question 11

What components of occlusion are found in primary teeth but not in permanent teeth?

Answer 11

Anterior spacing
Leeway space
Upright deciduous incisors

Question 12

What is anterior spacing?

Answer 12

Space between the primary anterior teeth so there is no crowding in the permanent dentition

Question 13

What is Leeway Space?

Answer 13

Extra mesiodistal space occupied by the primary molars which are wider than the premolars which will replace them
Usually equates to 1.5mm per side on the upper arch and 2.5mm on the lower arch

Question 14

What’s the difference in incisor occlusion between primary and permanent teeth?

Answer 14

Deciduous incisors are upright, but permanent incisors are proclined leading to an increase in A-P arch length