Tooth Morphology

Maxillary central incisors (11 / 21)

1. Crown:root Ratio 1:1

2. Incisal slopes 1/3 crown

3. Mesial-incisal corner more square (~90 degree angle)

4. Disto-incisal corner more round

5. Distal half of crown bulges out of the tooth more than the mesial.

6. Non-twisted crown

7. Groove on distal (all teeth)

8. Potential root curve to distal

Maxillary lateral incisor (12 / 22)

1. Crown:root Ratio 1:2 ; Incisal slopes 1/5 Crown

2. Asymmetrical crown: NOT symmetrical from medial to distal when viewing labial side of crown

3. Mesial-incisal corner more square (~90 degree angle)

4. Disto-incisal corner more round

5. Distal half of crown bulges out of the tooth more than the mesial.

6. Slightly twisted crown in line with teeth arch

7. Groove on distal (all teeth)

8. Potential root curve to distal

Mandibular lateral incisor (32 / 42)

1. Crown:root Ratio 1:2

2. Symmetrical from medial to distal when viewing labial side of crown

3. Twisting of crown on root towards distal side to follow arch of dentition

4. Groove on distal (all teeth)

5. Potential root curve to distal

Maxillary Canine (13 / 23)

1. Incisal edge 1/3 of crown

2. Crown bulges distally and medially on root (when viewed from buccal)

3. Crown shape is ~equilateral triangle (when viewed from proximal)

4. Crown does not lean to lingual

5. Large cingulum with pit

6. Palatal cusp ridge often present (down center of palatal surface dividing fossa)

7. Prominent marginal ridges

8. Round/Triangular cross section of root

R from L

1. Distal slope of incisal edge is longer than mesial

2. Distal surface is more convex (larger bulge) than mesial

3. Crown bulges more at distal

Mandibular Canine (33 / 43)

1. Incisal edge 1/5 of crown

2. Crown continues in ~straight line from root (viewed from buccal)

3. Crown shape is ~scalene triangle (when viewed from proximal)

4. Crown leans to lingual

5. Small or less developed cingulum

6. Lingual cusp ridge not often present

7. Less Prominent marginal ridges

8. Round cross section of root

R from L

1. Distal slope of incisal edge is longer than mesial

2. Distal surface is more convex (larger bulge) than mesial

3. Crown bulges more at distal

Maxillary upper first premolar (14 / 24)

1. Crown shape is OVOID (egg shaped) whereas the lower premolars are round.

2. Canine fossa present on mesial

3. Buccal cusp is higher

4. Buccal cusp is wider on occlusal surface mesial to distal than palatal cusp

5. Palatal cusp in narrower & smaller

6. Buccal cusp is less centrally located relative to palatal cusp tip

How to tell right from left:

1. Canine fossa on mesial

Maxillary upper second premolar (15 / 25)

1. Crown shape is OVOID (egg shaped) whereas the lower premolars are round.

2. No Canine fossa present

3. Buccal cusp is higher

4. Buccal cusp is wider on occlusal surface

5. Palatal cusp in narrower & smaller

6. Buccal cusp is less centrally located relative to palatal cusp tip

How to tell right from left:

1. palatal cusp tip is toward the mesial of the tooth (highest at mesial side)

Mandibular lower first premolar (35 / 45)

1. Crown shape is round and not egg shaped.

2. 2 Occlusal fossa - Distal fossa largest

3. Groove on mesial side: groove crosses mesial marginal ridge onto vertical surface of tooth

4. Mesial shorter than distal when viewed from occlusal

How to tell 1st from 2nd:

1. Buccal cusp larger than lingual cusp = 1st (even height in 2nd)

How to tell right from left:

1. Distal occlusal fossa larger

2. Groove runs over mesial marginal ridge

Mandibular lower second premolar (36 / 37)

1. Crown shape is round therefore lower premolar.

2. 2 Occlusal fossa - Distal fossa largest

3. Groove on mesial side: groove crosses mesial marginal ridge onto vertical surface of tooth

4. Mesial shorter than distal when viewed from occlusal

How to tell 1st from 2nd:

1. No difference between buccal and lingual cusp = 2nd

How to tell right from left:

1. If one lingual cusp the tip of lingual cusp is closest to the mesial surface

2. If two lingual cusps the taller one is closest to mesial

Maxillary upper first molar (16 / 26)

How to tell 1st or 2nd molar:

1. Cusp of Carabelli 1(Y) 2(N)

2. Occlusal outline 1st(Rhomboid) 2nd(heart shaped)

3. Distopalatal cusp 1st(larger) 2nd(small or cut off)

4. Buccal cusps relative height 1st(same) 2nd(DB < PB)

5. MB cusp % surface 1st(1/2) 2nd(2/3)

6. Buccal groove ends % way down buccal surface 1st(1/2) 2nd(1/3)

7. Root splay 1st(more splay) 2nd (less splay)

How to tell right from left:

1. DP cusp is smallest

2. MP cusp is largest

3. Usually 2 roots on buccal, 1 on palatal

4. P cusps are functional cusps

5. Cusp of Carabelli on MP cusp (1st m only)

Maxillary upper second molar (17 / 27)

How to tell 1st or 2nd molar:

1. Cusp of Carabelli 1(Y) 2(N)

2. Occlusal outline 1st(Rhomboid) 2nd(heart shaped)

3. Distopalatal cusp 1st(larger) 2nd(small or cut off)

4. Buccal cusps relative height 1st(same) 2nd(DB < PB)

5. MB cusp % surface 1st(1/2) 2nd(2/3)

6. Buccal groove ends % way down buccal surface 1st(1/2) 2nd(1/3)

7. Root splay 1st(more splay) 2nd (less splay)

How to tell right from left:

1. DP cusp is smallest

2. MP cusp is largest

3. Usually 2 roots on buccal, 1 on palatal

4. P cusps are functional cusps

Mandibular lower first molar (36 / 46)

1. 3 buccal, 2 lingual cusps

2. Pattern is 3B (MB, DB, D) 2L (ML, DL)

3. Usually 2 roots

How to tell left from right:

1. B has 3 cusps

2. B side has "buccal inroll"

3. "distal" cusp on DB

4. M Cusps higher

5. M Root has deeper grooves

6. Root tips to distal

Mandibular lower second molar (37 / 47)

1. Hot cross bun pattern (only tooth)

2. 4 cusps B(MB, DB) and L(ML, DL)

3. 2 roots usually unless fused

How to tell right from left:

1. Buccal side has "buccal inroll"

2. M cusps are higher

3. M root has deeper grooves (usually)

4. Root tips curve to distal