What are the main differences between primary and secondary teeth? (6)
- Primary teeth are smaller
- Enamel is whiter and more opaque
- Enamel is more permeable and prone to wear
- Depth of enamel is more consistent and thinner
- More pronounced cervical margin with bulging enamel (instead of tapering gently at the cementum-enamel junction)
- Coronally bulbous (crowns)
How do the roots of primary teeth compare to secondary roots?
Primary teeth have shorter, weaker and lighter coloured roots.
Prominent pulp horns, with relatively large pulp chambers.
Very fine root canals
How does the appearance of a primary central incisor compare to the appearance of secondary central incisors?
The crown and root form is similar in primary and secondary - but smaller scale in primary.
Crown mesiodistal width is larger than cervico-incisal length.
Rounder, fuller, shovel-shaped crown
Describe the root of a primary maxillary central incisor
Tilts towards the distal, and slightly tilts labially.
Tapers to blunt apex
Describe the palatal and labial surface of the primary maxillary central incisor
Palatal - Large cingulum
Labial - pronounced bulge
Describe the appearance of a primary upper central incisor
- DI angle rounded
- MI angle sharp
- crown is small and plump
- MD and CI dimensions are nearly the same (almost a rounded square shape)
Which primary tooth is the smallest?
The lower (Md) primary central incisor
Describe the primary lower central incisor root
- Single root
- Tapered
- More rounded than the secondary incisior
- Distal incline
On which side is the cervical margin most curved on a primary lower central incisor?
Mesial side
On which surface of a primary lower central incisor is there a bulge at the CEJ?
Labial surface
How would you describe the shape of the crown on a primary lower central incisor?
Chisel shaped
How does the primary upper lateral incisor compare to the primary central incisor?
Smaller and narrower
On which side is the cervical margin most curved on a primary upper lateral incisor?
Mesial
Describe the appearance of a primary upper lateral incisor
DI angle rounded
MI angle sharp
Less pronounced palatal cingulum
Describe the appearance of the lower primary lateral incisors
- DI angle rounded
- MI angle sharp
- Larger than the lower central incisor
Describe the root of the lower lateral incisor
- single
- tapered
- round cross section
- distally incline
- generally longer than lower central incisor roots
How does the lingual surface of the lower lateral incisor compare to the lower primary central incisor?
The lingual surface of the lower lateral incisor is more concave
How would you describe the crown and appearance of the upper primary canine?
- Mesial slope is longer than the distal slope
- Conical crown
- Pronounced cervical bulge
- Pointed cusp
- Cervical margin extends further incisally on mesial surface than on distal surface
How does the crown of the primary upper canine compare to the secondary upper canine?
The primary crown is smaller and more bulbous
Describe the occlusal of the upper primary canine
- Diamond shape with rounded corners
- Labial and palatal longitudinal ridges extending from cusp tip
Describe the root of the upper primary canine
- Distal incline
- Slender tapering single root
- twice the length of crown
- Triangular cross section
How does the lower primary canine compare in size to the upper primary canine?
The lower primary canine is smaller and slimmer in comparison
Describe the root of the lower primary canine
- Single root
- Tapered
- Distal incline
- Slight labial incline
Describe the characteristics of the crown of the primary lower canine
- Distal slope longer than mesial slope (opposite to max. prim. canine)
- Lingual surface is concave
- Labial and lingual longitudinal ridges; lingual ridge often completely absent
cervical margin more curved on mesial side
