Paediatric tooth morphology

Question 1

When do deciduous teeth start to develop

Answer 1

7 weeks in utero

Question 2

When do deciduous teeth start to become mineralised

Answer 2

Approx at the 4 month of fatal development

Question 3

What is the pattern of eruption in deciduous teeth

Answer 3

Lower A's, Upper A's
Upper B's, Lower B's
Upper D's, Lower D's
Upper C's, Lower C's 
Upper E's, Lower E's

Question 4

When does eruption of deciduous teeth begin

Answer 4

6 months

Question 5

At what age is the primary dentition complete

Answer 5

2.5 years

Question 6

How many teeth are in the primary dentition

Answer 6

20 (10 maxillary, 10 mandibular) 
Central incisor (A)
Lateral incisor (B)
Canine (C)
1st molar (D)
2nd molar (E)

Question 7

Things to note in eruption patterns

Answer 7

If eruption is not fairly symmetrical in each arch
If certain teeth erupt before others when they’re not supposed to e.g. D’s erupting before A’s
Premature exfoliation

Question 8

What are natal teeth

Answer 8

Teeth that are present when a baby is born. Often not fully developed and have a weak root. Not common

Question 9

What are neonatal teeth

Answer 9

Teeth that erupt within the first 30 days of a birth

Question 10

What is an eruption cyst

Answer 10

Dentigerous cyst

Question 11

What is a dentigerous cyst

Answer 11

Common type of odontogenic cysts. An odontogenic cyst is a fluid-filled sac that develops in the jaw bone over a tooth that hasn’t erupted ye

Question 12

Key morphological characteristics of primary teeth

Answer 12

Crown:
Thinner enamel and dentine layers meaning caries can progress to the pulp more quickly. Easier pulpal exposure
Shorter clinical crowns meaning there is difficulty fitting matrix bands
Broad flat interproximal contact areas meaning there is more susceptibility for caries development

Roots:
Thin splayed roots meaning there is a greater fracture risk
Shallow pulpal floor and multiple canals meaning perforation risk and inter- radicular vs periodical lesions