dat 118 ch. 17

Permanent posterior teeth

Premolars and molars

Number of permanent premolars

8 (2 in each quadrant)

Number of permanent molars

12 (3 in each quadrant)

Root trunk

Part of a posterior tooth before root division

Bifurcated

Tooth with two roots

Trifurcated

Tooth with three roots

Furcation

Area where roots divide

Furcation crotch

Space between roots after division

Central fossa

Depression where developmental grooves meet

Triangular fossa

Fossa near the marginal ridges

Occlusal pit

Small pinpoint depression where grooves meet

Why are pits and grooves susceptible to caries?

Plaque retention and thin enamel walls

Premolars are succedaneous because

They replace primary molars

Old name for premolar

Bicuspid

Location of premolars

Posterior to canines and anterior to molars

Most premolars have how many roots?

One root

Only premolar usually with two roots

Maxillary first premolar

Maxillary first premolar numbers

5 and #12

Roots of maxillary first premolar

Two roots (buccal and lingual)

Cusps of maxillary first premolar

One buccal and one lingual cusp

Important root feature of maxillary first premolar

Deep mesial root concavity

Which premolar has a mesial marginal groove?

Maxillary first premolar

Unique cusp slope feature of maxillary first premolar

Mesial cusp slope longer than distal cusp slope

Buccal cusp compared with lingual cusp on maxillary first premolar

Buccal cusp is about 1 mm taller

Pulp horns in maxillary first premolar

Two

Maxillary second premolar numbers

4 and #13

Roots of maxillary second premolar

One root

Root canals of maxillary second premolar

One root canal

Lingual cusp of second premolar compared with first premolar

More equal in length to buccal cusp

Mesiobuccal cusp slope of maxillary second premolar

Shorter than distobuccal cusp slope

Shape of maxillary second premolar

Wider buccolingually than mesiodistally

Mandibular first premolar numbers

21 and #28

Functional cusp of mandibular first premolar

Buccal cusp

Lingual cusp of mandibular first premolar

Small and nonfunctional

Mandibular first premolar resembles which tooth?

Mandibular canine

Occlusal shape of mandibular first premolar

Diamond-shaped

Important groove on mandibular first premolar

Mesiolingual groove

Direction of crown tilt on mandibular first premolar

Lingually

Nickname for Class I metallic restorations on mandibular first premolars

Snake eyes

Mandibular second premolar numbers

20 and #29

Two forms of mandibular second premolar

Three-cusp type and two-cusp type

Most common form of mandibular second premolar

Three-cusp type

Cusps of three-cusp mandibular second premolar

One buccal and two lingual cusps

Groove pattern of three-cusp mandibular second premolar

Y-shaped

Groove pattern of two-cusp mandibular second premolar

U-shaped or H-shaped

Lingual groove is found on which type?

Three-cusp type

Three-cusp mandibular second premolar pulp horns

Three

Two-cusp mandibular second premolar pulp horns

Two

Meaning of molar

Grinding

Three types of molars

First, second, and third molars

6-year molar

First molar

12-year molar

Second molar

Wisdom teeth

Third molars

Permanent molars are what type of teeth?

Nonsuccedaneous

Maxillary molars usually have how many roots?

Three roots

Term for maxillary molars with 3 roots

Trifurcated

Major cusps of maxillary molars

MB, DB, ML, DL

Maxillary first molar numbers

3 and #14

Age of eruption of maxillary first molar

About 6 years

Largest tooth in maxillary arch

Maxillary first molar

Largest crown in permanent dentition

Maxillary first molar

Developmental lobes of maxillary first molar

Five

Fifth cusp of maxillary first molar

Cusp of Carabelli

Largest cusp of maxillary first molar

Mesiolingual cusp

Second largest cusp of maxillary first molar

Mesiobuccal cusp

Third largest cusp of maxillary first molar

Distobuccal cusp

Smallest major cusp of maxillary first molar

Distolingual cusp

Order of cusp size on maxillary first molar

ML, MB, DB, DL

Oblique ridge formed by

Mesiolingual cusp ridge and distobuccal cusp ridge

Largest root of maxillary first molar

Lingual root

Weakest root of maxillary first molar

Distobuccal root

Number of pulp canals in maxillary first molar

Three

Lingual groove of maxillary first molar

DL groove

Buccal groove divides which cusps?

MB and DB cusps

Maxillary second molar numbers

2 and #15

Age of eruption of maxillary second molar

12–13 years

Roots of maxillary second molar

Three

Roots compared with first molar

Smaller and less divergent

Most common crown shape of maxillary second molar

Rhomboidal

Less common crown shape of maxillary second molar

Heart-shaped

Distolingual cusp on maxillary second molar

Smaller or absent

Cusp of Carabelli on maxillary second molar

Usually absent

Root fusion is more common on which maxillary molar?

Second molar

Maxillary third molar numbers

1 and #16

Common name for maxillary third molars

Wisdom teeth

Most common crown shape of maxillary third molar

Heart-shaped

Typical number of cusps on maxillary third molar

Three

Roots of maxillary third molar

Often fused

Why are maxillary third molars commonly impacted?

Lack of space

Peg molar is associated with

Partial microdontia

Most variable tooth in dentition

Third molar

Mandibular molars usually have how many roots?

Two roots

Term for mandibular molars with two roots

Bifurcated

Mandibular molars are wider in which dimension?

Mesiodistally

Mandibular first molar numbers

19 and #30

Age of eruption of mandibular first molar

6–7 years

Usually first permanent tooth to erupt

Mandibular first molar

Number of cusps on mandibular first molar

Five

Cusps of mandibular first molar

MB, DB, Distal, ML, DL

Largest cusp of mandibular first molar

MB