2nd Upper Premolar Anatomy

Anatomy of the 2nd upper bicuspid (with my own sketches).

1. Second Upper Premolar Adam Bilski

2. Second Upper Premolar – notation : - Universal Numbering – 13 ( Left ), 4 (Right) FDI – 25 (L), 15 (R) Haderup’s - +5 (L), 5+ (R) Palmer/ Zsigmondy – 5 (L), 5 (R) Adam Maciej Bilski

3. Formation of the tooth : First evidence of calcification 2 – 2,25 yr Enamel completed 6-7 yr Eruption 10-12 yr ( also then – K9 and 1st) Root completed 12-14 yr Adam Maciej Bilski

4. v Adam Maciej Bilski

5. Adam Maciej Bilski

6. 2nd upper premolar – blood supply : Adam Maciej Bilski

7. Trigeminal Nerve (V)  2nd Branch (V2) Adam Maciej Bilski

8. Second Upper Premolar – occlusion : Articulating with: 1st molar ( mesial half) 2nd premolar ( distal half) Adam Maciej Bilski

9. Their function is to masticate , and maintain the vertical dimention of occlusion (*OVD) . * Vertical Dimention of Occlusion - is a term used in dentistry to indicate the superior- inferior relationship of the  maxilla  and the  mandible   when the teeth are   occluded  in maximum intercuspation . *RVD – Rest Vertical Dimention * Adam Maciej Bilski

10. Aesthetics Adam Maciej Bilski

11. Adam Maciej Bilski

12. Left Upper 2nd Premolar ( buccal / facial aspect ): M D Cusp tip is less pointed , and towards mesial side Mesial slope is shorter than distal ( opposite to 1st premolar ) Buccal ridge is not as prominent as in maxillary 1st premolar Cervical line is less curvy than in 1st premolar Adam Maciej Bilski

13. 10 specimens of 2nd upper premolars ( buccal aspect ): Trapezoid outline of the crown visible ( smallest line – cervical part of the tooth ) but it’s more oval than 1st M D Adam Maciej Bilski

14. Left Upper 2nd Premolar ( palatal / lingual aspect ): D M Lingual cusp the same height as buccal one Crown is 7,5 - 8,5 mm long Mesial slope shorter Adam Maciej Bilski

15. Left Upper 2nd Premolar ( mesial aspect ): P B Cusps at nearly the same level The occlusal table is narrow Crown is smooth and convex , but root has a deep developmental depression The contact point (with 1st premolar ) is occlusaly on the middle third and slightly to the buccal side Buccal cusp is slightly sharper than lingual Adam Maciej Bilski

16. 10 specimens of 2nd upper premolars ( mesial aspect ): Adam Maciej Bilski

17. Left Upper 2nd Premolar ( distal aspect ): P B The surface is smooth and convex Distal marginal ridge is more cervical than mesial marginal ridge Contact point (with 1st molar ) is more cervically positioned and placed more bucally than on the mesial aspect ( still it’s on the middle third) Adam Maciej Bilski

18. Left Upper 2nd Premolar ( occlusal aspect ): B P M D The buccal cusp is less developed than the palatal one ( which differs it from the 1st premolar ) The amount of fissures is also higher , so higher probability of an additional buccal cusp The outline is rounded Tendency of radiating suplementary grooves from the central groove Central groove shorter than in 1st Adam Maciej Bilski

19. 10 specimens of 2nd upper premolars ( occlusal aspect ): Adam Maciej Bilski

20. Root: Lenght of root – 13 - 14 mm ( longer then the 1st one’s ) Usually 1 ( very rarely 2 roots present ) In case of 2 the lingual is shorter and its apex is more blunt From lateral view – usually cervical part of root and crown is the thickest Often pointed distally at the apical part (not a rule though ) Adam Maciej Bilski

21. Root Canal: 21,5 mm Not well-defined border of pulp- root canal Pulp horns often visible Pulp cavity narrows usually at the apical half of the tooth Adam Maciej Bilski

22. Dentinal islands pulpal projections or fins are sometimes present at the level of the CEJ OR constrictions at the same level Adam Maciej Bilski

23. Adam Maciej Bilski

24. 1 root canal from the pulp to apex Adam Maciej Bilski

25. 1st Max. Premolar vs. 2nd Max. Premolar 1st 2nd Cusp tip pointed / sharp Cusp tip round Mesial slope longer Mesial slope shorter Cusp tip towards distal Cusp tip towards short Lingual cusp shorter ( about 1 mm) Cusps at about same level 2 roots 1 root ( sometimes biforcated ) 2 root canals 1 or 2 root canals Shorter on avarage Longer on avarage Adam Maciej Bilski

26. Pre-treatment radiograph : 32 year old male patient Pain There has to be endodontic treatment under the temporary restoration Adam Maciej Bilski

27. Post- treatment – 3 root canals visible , with 3 different foramina ( filled with gutta-percha points and root canal sealer )  Adam Maciej Bilski

28. 2nd premolars were blocked and couldn’t erupt correctly they have to be removed Adam Maciej Bilski

29. 1st PM 1st MO Adam Maciej Bilski

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33. Nicely erupted Adam Maciej Bilski

34. Adam Bilski Adam Maciej Bilski