The permanent mandibular second molar is the 7th tooth from the midline. It has 4 cusps of nearly equal size and a simpler occlusal design than the first molar, lacking a distal cusp and distobuccal groove. It resembles the first molar but is smaller in all dimensions. It develops later than the first molar, with initiation of calcification around 2.5-3 years and eruption typically occurring between 11-13 years of age. It has 2 roots that are shorter and less divergent than the first molar roots.

4. Mandibular second molar
DR Jameel kifayatullah
Demonstrator oral biology kcd
24/05/2017

5. Permanent mandibular second molar

6. PERMANANENT MANDIBULAR
SECOND MOLAR
• Arch position: 7th from midline
mesial contact: Permanent
mandibular first molar
distal contact: permanent
mandibular third molar if/when
it erupts

7. General form and function
• Resembles the first molar in many respects
though it is more symmetrical
• Smaller in all dimensions than mandibular first
molar.
• Least complicated occlusal design
• Only 4 cusps present
• No distobuccal groove
• No distal cusp
• Grinding function

8. Cusps
• 4 cusps of nearly equal size in mandibular
second molar
• Mandibular first molar : 5 cusps of differing
sizes
• 4 developmental lobes:MB,DB,ML,DL lobes

9. Developmental table
• Initiation of calcification:2.5-3 years
• Completion of enamel: 7-8 years
• Eruption: 11-13 years
• Completion of root: 14-15 years

10. Buccal aspect

11. Buccal aspect
• Trapezoidal
• Shorter occlusogingivally and narrower
mesiodistally
• Mesial margin: concave from cervical line to
contact area and convex occlusally
• Distal margin: more rounded or convex
• Cervical line: curvature less like that of first
molar ,some may exhibit dip over bifuraction
area

12. Buccal aspect
Occlusal Margin
• divided into two equal halves by the buccal
groove
• the two buccal cusps Mesiobuccal and
distobuccal cusps nearly equal in length

13. Buccal aspect
• Buccal groove ends in buccal pit/ may fade out
in middle third
• No distobuccal groove
• Buccogingival ridge in cervical third
horizontally running more prominent in mesial
portion

14. BUCCOCERVICAL RIDGE

15. Buccal aspect
• Mesial contact : junction of occlusal and
middle third
• Distal contact: slightly cervical ,but still at
junction of occlusal and middle third

16. Lingual Aspect

17. LINGUAL ASPECT
• TRAPEZOIDAL
• Shorter occlusocervically and narrower
mesiodistally than first molar
• Mesial,distal and cervical outlines similar to
lingual surface of mandibular first molar
• i.e concave mesial margin from contact area
to cervical line and then occlusally convex
• Convex distal margin
• Shorter cervical line mesiodistally located at
more occlusal level than buccal surface and
irregular to nearly straight

18. Lingual aspect
• OCCLUSAL OUTLINE: divided into half by the
lingual groove
• Only the two lingual cusps(ML and DL) visible
• Crown convergence lingually---part of mesial
and distal surfaces seen from this view.
• The height of contour is in middle third

22. Mesial aspect
• Mesial contact area ovoid whereas mesial
contact area of mandibular first molar is
round/slightly ovoid.
• Crown wider buccolingually on mesial aspect
than distal aspect(right from left
distinguished)

23. Distal aspect
• No distal cusp contour
• No distobuccal groove
• Less convergence of buccal surface towards the
distal.
• Distal surface is about the same size as mesial
and little of buccal surface visible.
• Contact area centered on the distal surface both
buccolingually and occlusogingivally.
• Irregular wider BL than occlusogingivally

25. Lingual tilt

27. Occlusal surface

28. Occlusal table

29. Occlusal view
• Rectangular outline
• 4 cusps two buccal two lingual
• Occlusal surface of second considerably
different from that of first because no distal
cusp and all cusps are of equal size.
• Cross shaped groove pattern: well defined
central grooove crossed by buccal groove and
lingual groove.

30. Occlusal view
• 3 occlusal pits; Central pit in central fossa
mesial pit in mesial triangular fossa
distal pit in distal triangular fossa
• Two transverse ridges

31. Occlusal table

32. Transverse ridge

33. occlusion

34. roots
• 2 roots i.e mesial and distal
• Smaller ,shorter and less divergent in
placement than those of first molar
• Root branches closer together
• Root trunk of second molar longer than that
of first
• Distal angulation of roots

35. Mandibular second molar roots

36. Roots of mandibular second molar

37. Root