Dental Anatomy Quiz Mandibular 1st and 2nd Premolars

#21, #28 vs #20, #29

First Evidence of Calcification in Mandibular 1st Premolars

1 ¾ - 2 years

First Evidence of Calcification in Mandibular 2nd Premolars

2 ¼ - 2 ½ years

Crown Completion of Mandibular 1st Premolars

5-6 years

Crown Completion of Mandibular 2nd Premolars

6-7 years

Tooth Eruption of Mandibular 1st Premolars

10-12 years 

Tooth Eruption of Mandibular 2nd Premolars

11-12 years

Root Completion of Mandibular 1st Premolars

12-13 years

Root Completion of Mandibular 2nd Premolars

13-14 years

In comparing #20 and #21, which of the following is false

a. mesial marginal ridge is less prominent on #21 than it is on #20

b. only one root is generally present on both #20 and #21

c. lingual cusp of #21 is generally smaller than the lingual cusp of #20

d. #20 may have three cusps

e. none of the above

e. none of the above

The third and smallest cusp on the mandibular 2nd premolar is called

a. mesio-buccal cusp

b. distobuccal cusp

c. distolingual cusp

d. mesio-lingual cusp

e. none of the above

c. distolingual cusp

The transverse ridge is most prominent on

a. #20

b. #21

c. #28

d. a and c

e. b and c

e. b and c

Which statement correctly compares #21 and #5

a. the buccal height of contour on #21 and on #5 is located on the middle 1/3 of the crown

b. the lingual profile is visible when viewing #5 and #21 from the buccal aspect

c. #21 has a much smaller lingual cusp than #5

d. a and c

e. b and c

c. #21 has a much smaller lingual cusp than #5

The transverse ridge on #28 extends

a. from the buccal cusp to the lingual cusp

b. from the buccal cusp to the apex of the central groove

c. from the mesiolingual cusp to the apex of the distolingual

d. from the central groove to the mesiolingual and mesiobuccal groove

a. from the buccal cusp to the lingual cusp

Choose the occlusal view that DOES NOT belong to a mandibular 2nd premolar

III

On Fig 6-32, the arrow points to which landmark?

mesiolingual groove 

Identify C in Fig 6-33

a. #20

b. #19

c. #27

d. #28

e. #29

d. #28

The figure is most likely the pulpal section of which tooth from Fig 6-33

C

The mandibular second premolar occludes with

a. maxillary second premolar and first molar

b. maxillary first and second premolars

c. mandibular second premolar and first molar

mandibular canine and first premolar

b. maxillary first and second premolars

Which of the following is true of mandibular 1st premolars

a. they have a rounded convex mesial surface

b. the mesial marginal ridge is more occlusal than the distal marginal ridge

c. they have functioning lingual cusps

d. a central groove is not present 

d. a central groove is not present 

Which statement is FALSE when comparing a mandibular 1st premolar to a mandibular 2nd premolar

a. both have functioning lingual cusps

b. the occlusal table of three cusp #20 is square and for #21 it is diamond

c. The two-cusp type for #20 has a round/ square occlusal outline form and the three-cusp type has a square outline form

a. both have functioning lingual cusps

Which of the following is TRUE of the mandibular 2nd premolar three-cusp type

a. has only two fossa both of which are triangular fossa

b. does not have a lingual groove present

c. has a long straight central groove

d. has a central fossa that is distal to the center of the tooth in a M-D direction

d. has a central fossa that is distal to the center of the tooth in a M-D direction

In the occlusal view which is TRUE of mandibular 1st premolars

a. occlusal outline is diamond shaped and smaller than the 2nd premolar

b. mesiolingual groove is not present

c. groove routinely crosses the transverse ridge

d. there is minimal convergence to the lingual

a. occlusal outline is diamond shaped and smaller than the 2nd premolar

Which of the following statements is FALSE concerning geometric outlines of premolars

a. maxillary 1st premolars are hexagonal in the occlusal view

b. mandibular 1st premolars are diamond in the occlusal view

c. mandibular 2nd premolars (three-cusp type) are almost square in the occlusal view

d. mandibular 2nd premolars are trapezoidal in the proximal view

d. mandibular 2nd premolars are trapezoidal in the proximal view

True or False: for mandibular 1st premolars the mesial marginal ridge is more cervical than the distal marginal ridge

true

Which of the following statements is TRUE of BOTH mandibular premolars

a. in the occlusal view the outline form is square

b. mesial marginal ridge is located more cervical than distal marginal ridge

c. crowns are tipped lingually with respect to the root axis line (proximal view)

d. they both have a transverse ridge

c. crowns are tipped lingually with respect to the root axis line (proximal view)

In the occlusal view which is true of the mandibular 1st premolar

a. occlusal table is square and larger than a 2nd premolar

b. mesiolingual groove is common

c. groove is routinely crosses the transverse ridge

d. there is minimal convergence to the lingual

b. mesiolingual groove is common

In the occlusal view of this tooth, list the tooth # and the structure that is outlined

#20 and occlusal table

What are the boundaries of the occlusal table

the circumscription of 2 marginal ridges and 4 cusp ridges