Curvature of mesial CEJ wider that CEJ of distal
Cingulum slightly offset to distal side
Incisal angle – mesial angle 90 degrees
Mesial CEJ is more curved than distal CEJ
Apex of root is sharper than Max. Central
Linguogingival groove may be present
Mesial incisal angle sharper than distoincisal angle
Variation --- shovel shaped
Fan shaped crown
Mesioincisal angle slightly shaper than distoincisal
CEJ curvature is higher on the mesial than the distal
Crown appears tilted distally
Mesioincisal angle is sharper than distoincisal angle
In incisal view, the cingulum appears displaced toward the distal
Developmental depression on the distal surface of root
CEJ curves higher on the mesial than the distal
Mesial cusp slope is shorter than the distal cusp slope
Distal outline is shorter and rounder than the mesial outline from the labial view.
Mesial cusp slope is shorter than distal cusp slope.
CEJ curve is more toward incisal on the mesial surface
Larger than Max. 2nd premolar
2 roots ( buccal & lingual)
Mesial root concavity extending from contact point to bifurcation of root
Buccal cusp about 1mm longer than lingual cusp.
Only tooth that has a buccal cusp with a mesial cusp slope longer than the distal.
CEJ curvature is more on mesial than distal.
Occlusal view is hexagon shaped
Has prominent mesial marginal groove.
Central groove is “V” shaped.
Smaller than Max. 1st premolar
Only a single root
Buccal cusp about the same height as lingual cusp.
Lingual cusp slightly displaced to the mesial.
No mesial developmental depression
No mesial marginal groove on occlusal view.
Central groove is shorter than central grove of the Max. 1st premolar.
Lingual cusp very small Looks like a cingulum.
Mesobuccal cusp slope shorter than distobuccal cusp slope.
Crown tapers toward lingual.
Occlusal view looks diamond shaped with a notch in the mesial outline at the mesiolingual groove.
2 types 2 cusp & 3 cusp
3 cusp has a square shape from occusal view
Mesial marginal ridge straighter than distal marginal ridge from occlusal view.
“V” shaped central groove joins with lingual groove to form a “Y” shape.
2 cusp is either a “U” shaped central groove or a straight central groove that looks like an “H” from the occusal view.
Largest tooth in dentition.
3 roots (2 buccal & 1 lingual (longest))
4 cusp with variable 5th cusp off the mesiolingual cusp (Cusp of Carabelli)
Cusp size from largest to smallest--- mesiolingual, mesiobuccal, distobuccal, distolingual
Occlusal view has an overall rhomboidal outline.
Prominent oblique ridge.
Permanent Maxillary 2nd Molar #2 & #15
Distolingual cusp very small
Occlusal view may be rhomboidal or heart shaped.
Permanent Maxillary 3rd Molar #1 & #16
May be heart shaped. If so it has 3 cusp (No distolingual cusp)
May be rhomboid shaped. If so it has 4 cusp (very small distolingual cusp)
Distobuccal cusp much shorter than mesiobuccal cusp
Roots are fused with distobuccal root being the smallest
Roots are curved distally.
5 cusp (3 buccal and 2 lingual)
2 roots (mesial and distal)
Mesiobuccal cusp in the largest
Buccal cervical ridge more prominent in mesial
Mesial marginal groove notches mesial marginal ridge
Occusal view has a pentagon shape with the 5th side created by the distal cusp.
Size of cusp (from largest to smallest) mesiobuccal, mesiolingual, distolingual, distobuccal, distal
Permanent Mandibular 2nd Molar #18 & #31
4 cusp all cusp equal size.
Outline of occusal view is rectangular
Cross-shaped groove pattern
2 transverse ridges
Molar is wider buccolingually on the mesial surfaces than the distal.
Crown tapers distally when viewed from mesial aspect.