Tooth Morphology

Question 1

When is the initiation stage of tooth development?

Answer 1

6-7 weeks

Question 2

When is the bud stage of tooth development?

Answer 2

As early as the 6th week

Question 3

When is the cap stage in tooth development?

Answer 3

8-10 weeks

Question 4

When is the bell stage of tooth development?

Answer 4

11-12+ weeks

Question 5

What structures are formed in the bud tooth development stage?

Answer 5

Tooth bud
Oral epithelium
Mesenchyme

Question 6

What structures are formed during the cap stage of tooth development?

Answer 6

Enamel organ
Dental papilla
Dental sac

Question 7

What does the enamel organ produce?

Answer 7

Enamel

Question 8

What does the dental papilla produce?

Answer 8

Dentin
Pulp

Question 9

What does the dental sac produce? (PAC the sac)

Answer 9

Periodontal Ligament
Alveolar bone
Cementum

Question 10

What does the tooth germ give rise to that makes up a tooth?

Answer 10

Enamel
Dentin
Cementum
Pulp

Question 11

What are the final stages in tooth development?

Answer 11

Apposition
Maturation

Question 12

Dental tissues fully mineralized

Answer 12

Maturation stage

Question 13

Enamel, dentin and cementum secreted in successive layers
initially as a matrix

Answer 13

Apposition stage

Question 14

What teeth have wide and longer crowns with straight incisal edges?

Answer 14

Maxillary central incisors
#8, #9

Question 15

 Smaller and more rounded edges with straight incisal edge
 Most likely to have lingual caries
 Most often affected by microdontia

Answer 15

Maxillary lateral incisors
#7, #10

Question 16

 Rounded facial surface with a single pointed cusp
 Longest root in the mouth
 Largest cingulum

Answer 16

Maxillary canines
#6, #11

Question 17

 Most commonly extracted
 Most likely have divided root
 Long central groove that extends over mesial marginal ridge
 Mesial crown concavity

Answer 17

Maxillary 1st premolars
#5, #12

Question 18

Short central groove, only 1/3 of occlusal surface

Answer 18

Maxillary 2nd premolars
#4, #13

Question 19

 3 roots
 Has oblique ridge (runs from DB cusp to ML cusp)
 Likely to have Cusp of Carabelli

Answer 19

Maxillary 1st molars
#3, #14

Question 20

 3 roots
 Oblique ridge (not as pronounced)
 NO cusp of Carabelli

Answer 20

Maxillary 2nd molars
#2, #15

Question 21

 Edges more rounded
 Incisal edge slopes distally slightly

Answer 21

Mandibular lateral incisors
#24, #26

Question 22

The most symmetrical teeth

Answer 22

Mandibular central incisors
#24, #25

Question 23

 One single cusp tip (not as pointed as maxillary)
 Rare bifurcated root (facial/lingual)

Answer 23

Mandibular canines
#22, #27

Question 24

 Most commonly extracted
 Short lingual cusp that is usually non-functional

Answer 24

Mandibular 1st premolars
#21, #28

Question 25

 Functional lingual cusp  Often has two lingual cusps

Answer 25

Mandibular 2nd premolars #20, #29

Question 26

 5 cusps  2 roots (mesial root may have two canals)  2 buccal pits  Zig-zag central groove

Answer 26

Mandibular 1st molars #19, #30

Question 27

 4 cusps  2 roots  1 buccal pit  Cross central groove

Answer 27

Mandibular 2nd molars #18, #31

Question 28

 Wider MD than they are long  Unlike permanent centrals there are no mamelons  Cingulum, lingual marginal ridges & fossa more prominent than on the permanent successor  Single root that tapers at the apex

Answer 28

Primary maxillary centrals E & F

Question 29

 Similar to the central but smaller  Longer from the incisal edge to the cervical line than mesial to distal (opposite of the central)  Incisal angles are more rounded than the central  Root is longer in proportion to the crown

Answer 29

Primary maxillary laterals D & G

Question 30

 Similar to successor only smaller  Prominent cingulum

Answer 30

Primary mandibular centrals O & P

Question 31

 Crown is wider and longer than the central * Incisal edge slopes distally  Cingulum is more developed with a deeper lingual fossa

Answer 31

Primary mandibular lateral incisors Q & N

Question 32

 Considerably smaller than permanent successor  Sharper cusp tip when first erupted  Root twice as long as crown

Answer 32

Primary maxillary canines C & H

Question 33

 Smaller than maxillary  Smoother lingual surface  Single root not as long as maxillary

Answer 33

Primary mandibular canines M & R

Question 34

What resemble permanent first molars?

Answer 34

Primary second molars

Question 35

 May resemble maxillary premolars  May have 3 or 4 cusps  Buccal groove separates two buccal cusps  3 roots: MB, DB and lingual  Lingual root is longest

Answer 35

Primary maxillary first molars B & I

Question 36

 Larger than the primary maxillary first molar  Closely resembles the permanent maxillary first molar but is smaller in all dimensions  4 cusps  May have a Cusp of Carabelli  Has oblique groove  3 roots

Answer 36

Primary maxillary second molars A & J

Question 37

 Does not resemble any other tooth in the primary or permanent dentition – most unique anatomy  Prominent buccal cervical ridge  4 cusps: mesial cusps are larger  ML cusp is the widest & long and pointed  Transverse ridge passes between the MB and ML cusps

Answer 37

Primary mandibular first molars L & S

Question 38

 Larger than the primary first molar  Closely resemble the form of the permanent mandibular first molar: 5 cusps  3 buccal cusps nearly equal in size  Oval occlusal shape  2 roots

Answer 38

Primary mandibular second molars K & T