Tooth Morphology Flashcards
1
Q
Mandibular central incisor - Labial Aspect
A
- Crown 2x long as mesiodistal aspect
- Roughly triangular with base at incisal line
- Rounded CEJ
- Mesio-incisal angle sharper than distal
- Convex surface; flatter mesio-distally at incisal edge
- Contact area in the incisal 1/3
2
Q
Mandibular central incisor - Lingual Aspect
A
- Smooth and slightly concave from incisal to cervix
- Less concave from mesial to distal
- Cingulum, mesial and distal marginal ridges less defined than maxillary centrals
- Lingual pits/fissures rarely present
- Apical 1/3 may have slight distal inclination
3
Q
Mandibular central incisor - Mesial and Distal Aspects
A
- Incisal edge has lingual inclination
- Triangular in outline (base towards root)
- CEJ more pronounced on mesial aspect
- Distal root developmental groove deeper than mesial
4
Q
Mandibular central incisor - Root structure
A
- Flat below CEJ
- Developmental depression on mesial and distal aspects
- Distal groove deeper than mesial
- Apex may have slight distal inclination
5
Q
Maxillary central incisor - Labial Aspect
A
- Crown - 4 line margins
- Cervical margin crests towards distal
- Convex from mesial-distal and cervical to incisal
- Mesial margin- longer and straighter than the distal
- Mesio incisal angle sharper than distal
- Contact area in incisal 1/3
6
Q
Maxillary central incisor - Palatal Aspect
A
- Concave crown
- Distinct mesial and distal ridges
- Shovel shaped
- Cingulum may be single or divided
7
Q
Maxillary central incisor - Mesial and Distal Aspects
A
- Crown is triangular/wedge shaped: base at cervical 1/3 and apex at incisal apex
- cervical curvature of the CEJ is usually greater on mesial aspect
- Less defined CEJ on distal
8
Q
Maxillary Central Incisor - Root Structure
A
- Conical in shape
- Rounded at apex
- 1 root canal, 2 pulp cornua
- Immature/newly emerged teeth more sensitive to thermal changes
- Pulp chamber decreases with age
9
Q
Mandibular Lateral Incisor - Labial Aspect
A
- Slightly wider mesio-distally and longer inciso-cervically than central incisor
- Mesial side slightly longer than distal
- Distal lobe is larger than mesial lobe
10
Q
Mandibular Lateral Incisor - Lingual Aspect
A
- Lingual fossa slightly more developed
- Root is usually straight, longer and thicker
- Proximal grooves often give appearance of double root
- Apex may have a labial/distal inclination
11
Q
Maxillary Lateral Incisor - Labial Aspect
A
- Same line angles as the central: Mesial and distal line angles are more curved
- Labial surface: more convex than central
- Narrower mesio-distally and shorter cervico-incisally than the central
- Mesio incisal angle is sharper than the distal
12
Q
Maxillary Lateral Incisor - Palatal Aspect
A
- Mesial and distal margins are more pronounced
- Cingulum is usually prominent –> palatal concavity appears deeper
- Deep pit may be present in the cingulum
13
Q
Maxillary Lateral Incisor - Mesial and Distal Aspects
A
- Wedge shaped
- Greater curvature of CEJ on mesial
- Distal surface rounded
14
Q
Maxillary Lateral Incisor - Root Structure
A
- Same length as central root: may be longer
- Apical 1/3 often distally inclined and terminates sharply
- Narrow/Flattened mesiodistally
- 2 pulp cornua
15
Q
Mandibular Canines - Labial Aspect
A
- Crown generally narrower mesiodistally than maxillary crown
- Crown longer and more symmetrical than maxillary
- Mesio-incisal angle shorter than distal
- More pronounced labial ridge
- Cusp tip not as developed as maxillary crown
16
Q
Mandibular Canine - Lingual Aspect
A
- Lingual features less pronounced
- No lingual pits
- Ridges less distinct
- Lingual fossae less developed
17
Q
Mandibular Canine - Mesial Aspect
A
- Wedge shaped and a pointed cusp
- Less developed cingulum and thinner marginal ridges
- Cusp tip is on the long axis of the tooth
- Cervical line curves toward the incisal aspect
18
Q
Mandibular Canine - Distal Aspect
A
- Wedge Shaped
- Both mesial and distal proximal surfaces are longer than those of the 13 and 23
- Cervical line shows less curvature toward the cusp tip
- Distal surface above the contact point shows a greater concavity
19
Q
Maxillary Canine - Labial Aspect
A
- Cusp tip forms approx 1/3 of crown
- Distal marginal ridge is more developed and heavier than the mesial
- Mid lobe extension is most developed and forms cusp tip
- Palatal lobe: longer and thicker than the incisors, canines are wider labiopalatally
20
Q
Maxillary Canine - Proximal Aspect
A
- Distal marginal ridge is more developed and heavier than the mesial
- Distal surface is smaller and more concave than mesial above the contact point
- Mesial root has a comparatively shallow depression
21
Q
Canine Root
A
- Triangular (resist deplacement forces)
- Wider labially than palatally
- Apex generally blunt
- May have palatal or distal inclination
- Developmental depression appears to divide the root into two (anchorage and prevention of rotation)
22
Q
Mandibular 1st premolar - Buccal Aspect
A
- Large and sharp buccal cusp, similar to lower canine
- Develops from 3 facial lobes and 1 lingual lobe
- Mid lobe most developed
- Mesial cusp ridge is shorter than distal
- Convex mesio-distally and cervico-occlusally
23
Q
Mandibular 1st premolar - Lingual Aspect
A
- Crown tapers lingually
- Lingual cusp small and pointed
- Mesiolingual developmental groove crosses over mesial groove
- Most of buccal cusp is visible from lingual aspect
24
Q
Mandibular 1st premolar - Occlusal Aspect
A
- Rounded shape
- Mid buccal lobe forms bulk of crown: forms part of a transverse ridge
- Very small lingual cusp
- Both cusps lingually inclinded
- 2 fossa present - mesial and distal
- Mesial fossa smallest - mesial pit and mesiolingual development groove travels over the mesiolingual marginal ridge
- Distal fossa much larger, presents with a broader contact area
25
Mandibular 1st premolar - Proximal Aspects
- Mesiolingual groove is visible only on mesial aspect
- Distal marginal ridge is more developed than the mesial
- Convexity of distal aspect is greater than the mesial
26
Mandibular 2nd premolar - Buccal Aspect
- shorter buccal cusp than 1st premolar
- Mesiobuccal and distobuccal ridges are more rounded
- Cusp tip is displaced toward the mesial
27
Mandibular 2nd premolar - Lingual surfaces
- Lingual cusps are larger than 1st premolar
| - 3 cusp form has a lingual developmental groove between the 2 lingual cusps
28
Mandibular 2nd premolar - proximal surfaces
- Distal marginal ridge is lower than mesial marginal ridge
- Broad proximal contact area
- No mesiolingual developmental groove
29
Mandibular 2nd premolar - Occlusal aspect
- Buccal cusp is shorter than the 1st premolar and the lingual cusp is more pronounced
- Mesial, distal, buccal and lingual surfaces are wider and more rounded
- Shallower developmental grooves and more supplemental grooves
- Well defined transverse ridge, seldom unites with the lingual cusp
30
Maxillary 1st premolar - Occlusal Aspect
- Hexagonal
- Buccal profile is inverted V
- Sharp MB and DB
- Slightly convergent M and D profile
- Palatal profile is strongly convex
- Buccal ridge and depressions are visible
- Tip of palatal cusp is mesial from midline
- Mesial marginal ridge is shorter and interrupted by marginal groove
31
Maxillary 1st premolar - Buccal Aspect
- Buccal cusp: larger mesiodistally and occlusopalatally than the palatal cusp
- Kite shaped, similar to the canine
- Tip of buccal cusp is located distally to midline and separates the occlusal border into a long straight mesial ridge and short rounded distal ridge
- Mesial slope of cusp is longer than distal
- Distal slope shorter and rounder
- Broad longitudinal ridge extends from cusp tip to cervical line
- Convex
32
Maxillary 1st premolar - Palatal Aspect
- Similar to buccal
- Entire buccal outline visible
- Palatal cusp tip is mesial to midline of the crown
- No protuberances, ridges or depression
33
Maxillary 1st premolar – Mesial Aspect
- Mesial-marginal ridge is marked by mesial marginal groove
- Runs continuously from the central developmental groove on the occlusal aspect over the MM ridge and onto the occlusal 1/3 and towards the mid 1/3
- Developmental depression present on the cervical 1/3 of the crown and the cervical 1/3 root of the mesial aspect – canine fossa
34
Maxillary 1st premolar – Distal aspect
- Smaller than mesial aspect
- similar in outline
- shallower concavity present on distal aspect of crown or root
35
Maxillary 1st premolar – Root structure
- Buccal and palatal roots
- Usually two roots – bifurcation may not be complete
- Often delicate and curved
- If the root isn’t bifurcated, it’s compressed M-D with depressions on both mesial and distal surfaces
36
Maxillary 2nd premolar – Buccal and palatal aspects
- Cusps appear to be of equal height
- Viewed palatally, less of the buccal crown is visible than on the 1st premolar
- Root may be 1mm longer than the 1st premolar
- Buccal cusp smaller and less pointed than 1st
- Lingual cusp is displaced mesially
37
Maxillary 2nd premolar – Occlusal aspect
- Occlusal outline is ovoid in shape
- Cusps are further apart buccopalatally
- Cusps are of similar height
38
Maxillary 2nd premolar – Mesial and distal aspects
- No developmental groove on mesial marginal ridge
- Deeper fossa present on the distal aspect of the root
- mesial contact area is closer to the centre of the crown and distal contact area is closer to the buccal surface
