1. Molar Review

2. Maxillary Molars Three roots: L, MB, DB
Three major cusps: ML, MB, DB (trigon or tricuspid)
DL cusp : smallest, most variable
Lingual cusps unequal
Buccal cusps unequal (but closer to the same size)

3. Maxillary molars… Occlusal table centered over root
Lingual HOC at middle third
More of buccal surface visible from distal view

4. Maxillary molars... Wider F-L than M-D
Lingual root broader M-D than F-L*
Presence of DLG
Presence of an oblique ridge
Lingual pit common

5. Mandibular Molars Two roots: M and D (three pulp canals - MB, ML, D)
Four major cusps: MB, ML, DL, DB
Buccal cusps more equal
Lingual cusps more equal

6. Mandibular molars… Occlusal table lingually placed
(From occlusal view) more buccal surface visible
Lingual HOC in middle third
CE line on lingual more occlusal than on facial
Wider M-D than F-L
Buccal pit(s) common, lingual pit absent

7. How to differentiate between MAXILLARY first, second, and third molars…

8. Maxillary First Molar:
Four cusps; DL cusp smallest but present
Largest F-L dimension of any tooth*
Presence of Carabelli trait
ML and MB cusps large
(From occlusal view) less rhomboidal, more squarish, less lingual taper with possible divergence
MB & DL corners acute angle
ML & DB corners obtuse angle

9. Maxillary first molar…
Buccal roots appear “plier-handled”
MB root apex in line with MB cusp
Lingual root in line with long axis of tooth and buccal groove
Lingual root depression

10. Maxillary Second Molar:
Usually four cusps; 3 cusps possible:
DL diminished - heart-shaped
No Cusp of Carabelli
(From occlusal view) more rhomboidal than 1st: MB and DL angles acute, ML and DB obtuse

11. Maxillary second molar…
All roots more distally inclined than first, less flared
MB root apex in line with buccal groove

12. Maxillary Third Molar:
Typically three cusps; DL usually missing or greatly diminished
(From occlusal view) more heart-shaped, more supplementary grooves
Morphology most variable (trait shared with mandibular 3rd)
Occlusal table is narrower

13. Maxillary third molar... Shortest O-C dimension of any tooth*
Crown:root ratio nearly 1:1
Roots typically fused, very distally inclined

14. How to differentiate between MANDIBULAR first, second, and third molars…

15. Mandibular First Molar:
Largest M-D dimension of any tooth*
Five cusps; D smallest
Five developmental pits (M,Cen,D,MB,DB)
Four developmental grooves
2 buccal (MB & DB), 1 central, lingual
No transverse ridges (?)

16. Mandibular first molar…
Buccal surface wider than lingual surface
Mesial surface wider than distal surface
Mesial and distal marginal grooves present
Presence of mesial and distal root concavities
M root has greatest F-L dimension of any tooth*

17. Mandibular Second Molar:
Four cusps; no D cusp
Single buccal groove
Four developmental pits (M,Cen,D,Buc)
Occlusal grooves exhibit a “+” pattern
Two transverse ridges
MB prominence in cervical third

18. Mandibular second molar…
Buccal and lingual dimensions more equal
Mesial and distal dimensions more equal
No pronounced marginal grooves
No root concavities
Roots more distally inclined

19. Mandibular Third Molar:
Four to five cusps
Occlusal table narrower; anatomy variable
Extensive supplementary grooves
Crown:root ratio more 1:1; roots fused
Shortest O-C crown dimension of all mandibulars*

20. Let’s look at some examples...

27. Final Wax Exam

31. Lights!