1. DENTAL ANATOMY 1st Semester 2008/2009 Academic Year
Department of Stomatology
School of Stomatology
Wenzhou Medical College

2. Primary (and Mixed) Dentition
Kevin Yang
Li Hong-qing

3. SECTION 1 Background Info.
Objectives
Dental formulae
Functions of primary dentition

4. A definitions Deciduous teeth Primary teeth Nicknames
Deciduous: fall off
Primary teeth
Nicknames
Milk teeth
Temporary teeth

5. B Dental formulae Primary teeth Permanent teeth I2/2+C1/1+M2/2=5/5
I2/2+C1/1+P2/2+M3/3=8/8

6. Teeth numbering
A to T

7. 1D to 20D

8. C functions
Mastication of food

9. Support the cheeks and lips

11. Speech formulation

12. Maintaining the space and arch continuity

13. SECTION 2 Developmental Data
Objective
Time ranges for primary and secondary tooth eruption
Time ranges crown and root formation for primary and secondary teeth
Oder of eruption of primary and secondary teeth

14. A important times for tooth emergence
No teeth
Birth 6(or8) months old:
Primary dentition only
6(or8) months-2(or21/2)old:
2(or21/2)-6(or53/4)years old:

16. Mixed dentition Adult dentition only 6(or53/4)years old: 6-9years old:

17. B crown and root development
General development
primary teeth: Lobes- crown calcifications- root formation, tooth eruption process- resorption- exfoliation
Succedaneous teeth: Lobes- crown calcifications- root formation, tooth eruption process

18. Average primary crown calcification time?
When does root formation begin?
When does tooth start to erupt?
How long does the eruption process last?
Order of emergence of primary teeth?
When do the primary tooth roots are completed?
What’s Mixed dentition? Age of mixed dentition?
Age of crown formation of 2nd teeth?
Oder of emergence for 2nd teeth?
1st and last emergence tooth of 2nd teeth?

20. SECTION 3 Dentition traits of all primary teeth
Specimens
The best: in kids mouth
Or: plastic model

22. General traits compared to secondary teeth
Smaller in size
Whiter
Marked constriction at cervix
Relative longer roots
Large pulp cavity, thin enamel and dentin layer
Less mineralized
More consistent shape

23. Traits of all primary anterior teeth
Cervical ridges on facial surfaces are prominent
Lingual cingula are prominent
Labial surfaces are smooth

24. Root traits of primary teeth
Long to the crown
Narrow mesiodistally
Roots bend labially

25. Traits of primary posterior teeth
Prominent cervical ridge
Narrow occlusal table

26. Buccal view: wide mesiodistally
Shallow occlusal anotomy

27. Few grooves or depressions
Primary second molar larger than primary first molar

28. Root traits of primary teeth
Root furcation near the crown, little or no trunk
Roots are thin or slender
Root number and relative size

29. SECTION 4 Class and Type Traits
Primary incisor traits
Primary canine traits
Primary molar traits

30. SECTION 5 pulp cavity Anterior teeth Posterior teeth (molars)
Large pulp cavity
Slight projection
Posterior teeth (molars)
Chamber Less elongated vertically
Pulp chamber in root crown
Long, narrow pulp horns