1. Premolars

2. Position of Premolars
Posterior
Succedaneous teeth

3. Maxillary Premolars
1st : (#5, #12)
2nd: (#4, #13)

4. Eruption of Maxillary Premolars
1st: 10 – 11 years
2nd: 10 – 12 years

5. Occlusion
Maxillary cuspids are distal to mandibular cuspids by a ½ a cusp
Maxillary premolars are distal to mandibular premolars by a ½ cusp

6. Maxillary 1st Premolar Mesial/distal view
CEJ straighter than anteriors
Buccal and lingual cusps centered over the root
Mesial concavity
Buccal cusp larger than lingual
Single or bifurcated root. Bifurcation more common.

7. Maxillary 1st Premolar Occlusal view
Point angles are sharp on buccal, rounded on lingual
More rounding on the distolingual than the mesiolingual.
Hexagontal or pentagontal outline
Bulkier on the mesial
Sharper line angles on the mesial than the distal.
Mesial marginal ridge with a mesiomarginal groove
Transverse ridge
Grooves – 6 (Central, mesial mesiobuccal, mesiolingual, distobuccal, distolingual)
Distobuccal groove is the longest.

8. Maxillary 1st Premolar Buccal view Mesial view Lingual view
Occlusal view

9. Maxillary 1st Premolar (Lingual view)
Maxillary Right (#5)
Premolars and 1st molar: # 5, #4, #3, left to right

10. Maxillary 2nd Premolar No mesial concavity or groove
Buccal and lingual cusps of equal size
Usually one root
Short central groove, more secondary grooves
Heavier marginal ridges
Max. R 1st premolar, #5

11. Maxillary 2nd Premolar Occlusal view: Cusps bulk on the mesial
Rectangular or oval occlusal table
Max. R 1st premolar, #5

12. Maxillary 2nd Premolar
Distal view: More of the occlusal table can be seen from the distal than from the mesial view. (True of 1st premolar also.)
Usually only one root, sometimes bifurcated.
Distal view
Mesial view

13. Maxillary 2nd Premolar Buccal view Distal view Lingual view
Occlusal view

14. Maxillary Premolars (Buccal view)5
Tip of the buccal cusp is distal to the midline, therefore the mesial cusp
ridge is longer than the distal cusp ridge.

15. Maxillary Premolars (Lingual view)12 5 13 4

16. Maxillary Premolars (Mesial/Distal)
2 roots
1 root
Notice the depression on the first premolar on the mesial view.

17. Maxillary Premolars (Occlusal view)

18. Mandibular Premolars Mandibular 1st: (#21, #28)
Mandibular 2nd: (#20, #29)

19. Mandibular Premolars
Mandibular 1st: Two cusps (Buccal and an afunctional lingual cusp)
Mandibular 2nd: Two or three cusps (One buccal, with one or two lingual cusps. Lingual cusp(s) afunctional.)

20. Eruption of Mandibular Premolars
Mandibular 1st: 10 – 12 years of age
Mandibular 2nd: years of age
Roots complete: 12 – 14 years of age

21. Occlusion of Mandibular Premolars
Mandibular 1st: Maxillary cuspid and 1st premolar
Mandibular 2nd: Maxillary 1st and 2nd premolars
Lingual tipping of crowns

22. Mandibular 1st Premolar
Two cusps: large buccal and small lingual
Mesiolingual groove
Mesial cusp ridge is shorter than distal cusp ridge
Tip of the buccal cusp is centrally located over the root
Mandibular R 1st premolar

23. Mandibular 1st Premolar
Only premolar where more of the occlusal table can be seen from the mesial view, rather than the distal view
Mandibular R 1st premolar

24. Mandibular 1st Premolar
Occlusal view:
Transverse ridge (union of two triangular ridges)
Pits
Diamond-shaped or triangular shaped
Mandibular R 1st premolar

25. Mandibular 1st Premolar (Left)
Buccal view
Mesial view
Lingual view
Occlusal view

26. Mandibular 2nd Premolar
Two or three cusps
Buccal cusp is the largest
In a 3 cusp form: ML is the second largest, DL is the smallest
Bulks to the mesial
Square or rectangular occlusal table
Mandibular R 2nd premolar

27. Mandibular 2nd Premolar
Occlusal view
Y shape: B, ML, DL
H shape: B, L
U shape: B, L
Most common
Mandibular R 2nd premolar

28. Mandibular 2nd Premolar (Right)
A. Buccal view
B. Occlusal view
C. Distal view

29. Mandibular Premolars (Buccal view)

30. Mandibular Premolars (Lingual view)

31. Mandibular Right Premolars (Mesial/Distal View)

32. Mandibular 2nd Premolars (Occlusal view)

33. References Woelfel and Scheid. Dental Anatomy,
6th Edition. Lippencott, Williams, and Wilkins,
2002, p
Brand and Isselhard. Anatomy of Orofacial
Structures,
6th Edition. Chapter 32 (p. 400 – 425),
7th Edition. Chapter 14 (p. 146 – 165).