Maxillary second premolar

lecture of maxillary second premolar

1. Menatalla M. Elhindawy

2. Morphology!!! A branch of biology that deals with the form and structure of animals and plants. T he form and structure of an organism or any of its parts.

3. Maxillary Second Premolar

4. Where is it??

5. Is it a successor??

6. It is a successor..

7. It is a successor.. Do we have problems??

8. Max. 2 nd premolar.. CHOROLOGY First evidence of calcification.. 2- 2 1\2 years. Enamel completed.. 6-7 years. Eruption.. 10-12 years. Root completion.. 12-14 years.

9. Max. 2 nd premolar.. In each aspect we need to full fill these requirements : Geometric outline. Outlines “M., D., B., L., cusp”. Contact areas or crest of curvatures. Surface anatomy. Cervical line. Root.

10. Max. 2 nd premolar.. LABIAL ASPECT Geometric outline Trapezoidal. II. Outline Mesial.. Slightly convex. Distal.. More convex. Cusp.. Short, less pointed and M. slop shorter then D. slop; tip is displaced to the M.

11. Max. 2 nd premolar.. LABIAL ASPECT III. Contact areas: M. at the junction bet. mid. and occ. 1\3s. D. at mid. of mid. 1\3. IV. Surface anatomy : Buccal and cervical ridges. V. Cervical line: convex root wise. VI. Root: single tapering from cervical to apical with a D. curved apecx .

12. Max. 2 nd premolar.. LINGUAL ASPECT Lingual convergence. Reversed outlines. Lingual cusp is sharp, same length as buccal cusp.

13. Max. 2 nd premolar.. MESIAL ASPECT Geometric outlin Trapezoidal. Outlines Buccal and lingual .. Slightly convex. Cusps.. Almost same length; greater distance between cusps which widen the occ. Surface.

14. Max. 2 nd premolar.. MESIAL ASPECT Crest of curtvture : Bucc . at junc. bet mid. and cervical ling.mid of the mid . IV. Surface anatomy : Aspect is smooth and convex with NO depressions. M. marginal ridge is more occ. than D. one. Contact area is broad. V. Cervical line: concave root wise. VI. Root: single; broad baccolingual with relatively blunt apex. Shallow developmental depression.

15. Max. 2 nd premolar.. DISTAL ASPECT Similar to the M. aspect. D. contact area is wider and more cervical. D. marginal ridge is more cervical. Straighter cervical lines. D eeper developmental depression.

16. Max. 2 nd premolar.. OCCLUSAL ASPECT Geometric outline: oval or rounded. Elevations: Cusps.. Both at the same size with wide distance inbetween. Marginal ridges.. thick, strong and well developed

17. Max. 2 nd premolar.. OCCLUSAL ASPECT Depressions: Central groove.. Short with multiple supplemtal grooves. Triangular fossae: near to each other; D. is larger and deeper than M.

18. Any questions??

19. Now Let’s compare 1 st and 2 nd maxillary premolars…

20. Let’s compare.. 1 st premolar Buccal aspect 2 nd premolar Buccal aspect Outlines: M. concave; D. less concave Cusp: M. slop longer than D.; tip is displaced to D. Contact areas: M. Just occ. to the mid. of the mid.1\3; D. at the junc. bet. mid. and occ. 1\3s Outlines: M. slightly convex ; D. convex Cusp: M. slop shorter than D.; tip is displaced to M. Contact areas: M. at the junc. bet. mid. and occ. 1\3s; D. at the mid. of the mid.1\3;

21. Let’s compare.. 1 st premolar Lingual aspect 2 nd premolar Lingual aspect Lingual cusp.. Shorter 1 mm than buccal Tip displaced to M. Sharp although the whole ling. surface is convex. Lingual cusp.. same length as the buccal. Sharp.

22. Let’s compare.. 1 st premolar Mesial aspect 2 nd premolar Mesial aspect Surface anatomy.. Canine fossa. Mesial marginal developmental groove. Root.. Bifurcation level mid root. Developmental depression. Surface anatomy.. smooth and convex with no depressions. Root.. Single; broad. Developmental depression.

23. Let’s compare.. 1 st premolar Distal aspect 2 nd premolar Distal aspect Surface anatomy.. No canine fossa. No mesial marginal developmental groove. Root.. Bifurcation level at the apical 1\3. Surface anatomy.. similar to M. aspect. Root.. Single; broad. Deeper developmental depression.

24. Let’s compare.. 1 st premolar Occlusal aspect 2 nd premolar Occlusal aspect Outline.. Hexagonal. Elevations.. Cusps.. Buccal and lingual. Marginal ridges.. Depressions.. Long central groove No supplementary ones. Mesial marginal developmental groove. 2 triangular fossae. Outline.. Oval or rounded Elevations.. Cusps.. Buccal and lingual. Marginal ridges.. Thicker ones Depressions.. short central groove Supplementary ones. 2 triangular fossae.

25. Any questions??

26. Thank you