How many deciduous teeth are there ?
20
Which deciduous teeth are bigger than the teeth that succeed them ?
The deciduous molars are bigger than the permanent premolars
(Ds and Es are bigger than 4s and 5s)
What are the characteristics of deciduous teeth ?
- bulbous crowns with pronounced cervical margins
- very pointed cusps when they are newly erupted
- short less robust roots
- roots which resorb as the permanent teeth begin to erupt
- extremely fine root canals
What are the differences between deciduous teeth and permanent teeth ?
- deciduous teeth are smaller
- deciduous teeth have more of a constant shape
- deciduous teeth have larger pulp chambers with prominent pulp horns
What 2 characteristics are unique to deciduous dentition ?
- The enamel is thinner and has a different structure
- Microscopic neo-natal lines
What are microscopic neo-natal lines ?
- found in deciduous teeth and the permanent 1st molar
- these teeth are formed at birth and birth is a traumatic event so these lines form due to the metabolic disturbance
What are the characteristics of the deciduous maxillary central incisors ?
- crown length and width are equal
- root is longer than the crown
- no mammelons
- poorly defined marginal ridges and palatal fossa
What are the characteristics of the deciduous mandibular central incisors ?
- crown length is much shorter than permanent
- root is circular in the cross section
- no mammelons
- poorly defined marginal ridges and lingual cingulum
- low labial cingulum
What are the characteristics of the deciduous maxillary lateral incisors ?
- smaller than maxillary central incisor
- acute mesio-incisal angle
- obtuse disto-incisal angle
- rounded labial cingulum
What are the characteristics of the deciduous mandibular lateral incisors ?
- wider crown and longer root compared to mandibular central
- difficult to distinguish from deciduous maxillary lateral incisor
What are the characteristics of the deciduous maxillary canine ?
- more bulbous than permanent
- crown wider than it is tall
- if not symmetrical then the mesial incisal slope is longer than the permanent
- ridge from the cingulum to the tip of the cusp with 2 fossae on each side
What are the characteristics of the deciduous mandibular canine ?
- more slender than deciduous maxillary canine
- tip of cusp is mesially placed (asymmetrical)
What are the characteristics of the deciduous maxillary second molars ?
Note - morphology of Es = morphology of 6s
- 4 cusps
- carabelli trait on mesio palatal cusp
What are the characteristics of deciduous mandibular second molars ?
(Very similar to permanent mandibular first molar)
- crown has convex mesial and distal surfaces
- prominent buccal cervical bulge
- buccal surface inclines lingually
What are the characteristics of deciduous maxillary first molars ?
- irregular quadrilateral - buccal and palatal sides are parallel
- 2 cusps (separated by fissure)
- buccal cusp is bigger
- mesiobuccal molar tubercle
- 3 roots - distobuccal and palatal may be fused
What are the characteristics of deciduous mandibular first molar ?
- irregular quadrilateral - buccal and lingual sides parallel
- 4 cusps
- mesiodistal fissure between 2 buccal cusps and 2 lingual cusps
- ridge connects mesial cusps
- mesiobuccal molar tubercle
- 2 roots are flattened mesiodistally
What are the differences between deciduous maxillary central and lateral incisors ?
- lateral are smaller
- lateral have a concave palatal surface with more pronounced marginal ridges
- smaller palatal cingulum
How do you distinguish between Es and 6s ?
- by size
- by whiteness
- by the widely divergent roots
