Dental Anatomy - Mandibular Second Premolars

evidence of calcification of mandibular second premolars

2.5 years

enamel completion of mandibular second premolars

6-7 years

eruption of mandibular second premolars

11-12 years

root completion of mandibular second premolars

13-14 years

General Characteristics of mandibular second premolars

- larger of the mandibular premolars

- more molar like than canine like

- more functional occlusion

from the buccal aspect, mandibular second premolars

- have shape and features similar to first premolar

- buccal cusp is shorter and more blunted than first premolar

- buccal cusp is centered

- M and D cusp ridges are equal lengths

from the lingual aspect, mandibular second premolars have a lingual cusp that is (larger/smaller) than first premolars

larger

from the lingual aspect of mandibular second premolars, there is either _______ or _____ lingual cusps

one, two

the lingual cusp is (shorter/longer) than the buccal cusp on the lingual aspect of mandibular second premolars

shorter

there is (more/less) lingual convergence on the lingual aspect of mandibular second premolars

less

on the lingual aspect of mandibular second premolars, if there are 3 cusps, they are the

buccal cusp, mesiolingual cusp, and distolingual cusp

on the lingual aspect of mandibular second premolars, the lingual groove is ______ to the distal

offset (helps with R vs L)

from the mesial aspect of mandibular second premolars, there is (more/less) lingual inclination of the crown

less

from the mesial aspect of mandibular second premolars it is (wider/narrower) buccal-lingual

wider

from the mesial aspect of mandibular second premolars, it is (longer/shorter) occlusocervically

shorter

from the mesial aspect, the marginal ridge on mandibular second premolars is

horizontal

there (is/is not) a mesiolingual developmental groove

is not

from the mesial aspect of mandibular second premolars, the proximal contact area is at the junction of the _______ and _______ 1/3

occlusal, middle

on the mesial aspect of mandibular second premolars, the contact area is

- circular

- towards the buccal

on the mesial aspect of mandibular second premolars, the lingual HOC is in the

occlusal 1/3

on the mesial aspect of mandibular second premolars, the buccal HOC is in the

cervical 1/3

from the distal aspect of mandibular second premolars, the distal marginal ridge is located (more/less) cervical (good identifying feature)

more

on mandibular second premolars, if you can see more of the occlusal plane or the ridge is closer to the cervical when viewing proximally, it will point you to the

distal aspect

all 3 cusps (can/can not be) visible from the distal aspect

can

from the distal aspect of mandibular second premolars, the proximal contact area is

- located in the same place as the mesial

- slightly larger B-L

on the occlusal aspect of mandibular second premolars it has a _______ outline shape

square

there are __ and __ cusp types in mandibular second premolars

2, 3

the _____ cusp pattern is most common in mandibular second premolars (55%)

three

3 cusp mandibular second premolars

- Y pattern

- central and lingual grooves

- cusp size is largest to smallest B, ML, DL

- all cusps have 4 cusp ridges

on the occlusal aspect of mandibular second premolars of the "Y" type, there are mesial and distal triangular ____ and no transverse ridge

fossae

on the occlusal aspect of mandibular second premolars of the "Y" type, there are 4 occlusal grooves:

- central

- triangular

- marginal

- lingual

there are 3 occlusal pits on the occlusal aspect of mandibular second premolars of the "Y" type:

- mesial

- distal

- central

on mandibular second premolars of the "Y" type, the central pit is

- deepest

- central and lingual groove meet

the two cusp types on mandibular second premolars are

U or H

the H is (more/less) common than the U type

more

on two cusp types, the occlusal outline is (more/less) rounded and there is no central pit or lingual groove

more

of two cusp types, there (is/is not) convergence of the lingual cusp

is

of two cusp types, triangular ridges (do/do not form) a transverse ridge

do

on two cusp types, the buccal cusp is (larger/smaller) and (lower/higher) than the lingual cusp

larger, higher

the H type has (more/less) distinct triangular grooves

more

on U and H type mandibular second premolars, the mesial and distal fossae are

round in shape

the U type mandibular second premolars have a ______ central groove

curved

the H type mandibular second premolars have a ______ central groove

straight

the root is _____ and ______ on mandibular second premolars than the first premolars, and bifurcation is _____

longer, wider, rare

there are ___ or ___ pulp horns depending on the number of cusps on mandibular second premolars

2, 3

the cross section on mandibular second premolars is

ovoid

there is distal inclination of the ______ 1/3 on the root and pulp aspect of mandibular second premolars

apical