Posterior Flashcards
Upper first premolar
- Two cusps present – lingual cusp is shorter than buccal cusp by 1 mm
- Mesial slope of the buccal cusp is slightly longer than the distal slope.
- Canine fossae present on mesial surface
- MMDG (Mesial marginal developmental groove) is present on the mesial
surface - Occlusal surface – hexagonal in shape
- Longer central developmental groove
- Usually, two roots are present
Upper second premolar
- No canine fossa
- NO MMDG
- Distal surface of the buccal cusp is longer than mesial slope
- Occlusal surface – oval in shape
- Buccal and lingual cusp similar length
- Short central developmental groove
- Presence of supplementary grooves
- Mostly single root
Lower first premolar
Severe lingual inclination
- Severe lingual convergence
- Occlusal outline – diamond
- Snake eyes appearance – occlusal surface
- MLDG (mesiolingual developmental groove) is present
Lower second premolar – can have 2 or 3 cusps.
Occlusal surface – 2 cusp type
Oval shaped
- Has lingual convergence
- U-shaped or H-shaped CDG
- Supplementary groove present
Occlusal surface – 3 cusp type
- Square shaped
- No lingual inclination and no lingual convergence
- Y-shaped CDG
- One buccal cusp and two lingual cusp – one large mesiolingual cusp and
distolingual cusp - Supplementary grooves present
Upper molars, in general
- Thickness (Buccolingual) > Width (Mesiodistal)
- Two buccal roots and one palatal (longest root)
Upper first molar
Tubercle of carabelli present
- Occlusal surface is rhomboid with 4 cusps
- Mesiolingual is the largest cusp with tubercle of carabelli present
- Oblique ridge connects between ML (mesiolingual) and DB (distobuccal)
cusps
- Roots are long and widely placed
Upper second molar
- Occlusal surface is rhomboid (4 cusps) or heart-shaped (4 or 3 cusps)
- No tubercle of carabelli
- Roots are shorter and less widely placed
Upper third molar
- Occlusal surface is rhomboid or heart-shaped
- No tubercle of carabelli
- Multiple supplementary grooves
- Root is short and fused
- No distal contact area
Lower molars, in general
- Width (Mesiodistal) > Thickness (Buccolingual)
- Two roots – mesial and distal
Lower first molar
- Occlusal surface is hexagonal
- Has 5 cusps – Three buccal (Mesiobuccal, Distobuccal, and Distal) and two
lingual (Mesiolingual and Distolingual) - Roots are long and widely placed – mesial and distal
Lower second molar
- Has four cusps that are nearly equal in size
- Occlusal surface is rectangular
- Has cross-form developmental groove
- Roots are short and less widely placed
Lower third molar
- It may look like 1st molar (5 cups) or like 2nd molar (4 cups)
- Multiple supplementary grooves
- Roots are short, may be fused or distally curved
- No distal contact area
