Tooth Morph - Which side is which

Question 1

Tell me how to tell which side is which for upper central and lateral incisors and canines.

Answer 1

-Upper central incisor - Straighter sharper side is mesial.
Distal side is curved.

-Upper lateral incisor - distal incisal angle is more curved than mesial incisal angle.

-Upper canine - Prominent distal bulge.

Facial side (side facing outside of mouth) is convex.

Question 2

How to tell which side is which for upper 1st and 2nd premolars.

Answer 2

-Upper first premolar - mesial marginal developmental groove which crosses the mesial marginal ridge crosses the mesial side and the lingual cusp is mesial to the centre.

• Upper second premolar - lingual cusp is mesial to the centre.

taller/larger cusp is towards the facial side.

Question 3

How to tell which side is which for the upper molar teeth.

Answer 3

-Upper first molar - Distal lingual cusp is on the distal side and cusp of carabelli is on the mesial side.

-Upper second molar - Distal lingual cusp is on the distal side.

-Upper third molar - difficult to tell.

The two roots face the facial side of tooth.

Question 3

How to tell which side is which for lower central, lateral incisors and canine.

Answer 3

-Lower central incisor - very symmetrical, so difficult to tell.

-Lower lateral incisor - cingulum is twisted to distal side when looking at teeth from incisal side, when placed horizontally.

-Lower canine - distal bulge to the distal side. Mesial side is in line with the mesial root.

Facial side of tooth is convex.

Question 4

How to tell which side is which for lower premolars.

Answer 4

-Lower 1st premolar - Look at the two close pits. One pit comes off towards the mesial side crossing the mesiolingual groove.

Lower second premolar:
-2 cusp variation - Lingual cusp is towards the mesial side.

-3 cusp variation - mesiolingual cusp is larger than distolingual cusp.

Looking from proximal view - crown tilts away from facial side.

Question 5

How to tell which side is which for lower molars.

Answer 5

Lower 1st molar - distal cusp (which is the smallest of the 5 cusps) is towards distal.
crown converges (or tapers) towards distal.
distal side is more curved and convex, mesial side is more straight.

Lower 2nd molar - Crown again converges (or tapers) towards distal side.
distal side is convex, mesial outline is more straight.

Lower third molar - Difficult to tell.

In general, roots tilt distally and crown tilts away from facial from proximal view.