2. General Information
There are six maxillary molars, three in each quadrant
Like premolars, they are named for their position in the arch from
anterior to posterior
Permanent molars erupt posterior to the primary second molars and
do not replace deciduous teeth
Nonsuccedaneous
The first molar is the first permanent tooth to erupt
The mandibular first molar precedes the maxillary first molar by a few months
Both usually erupt before permanent central incisors
3. General Information
With the exception of the third molars, all maxillary molars have at
least four cusps.
The maxillary first molar usually has a fifth, nonfunctioning cusp, or
tubercle, that is positioned on another cusp
The fifth cusp is known as the cusp of Carabelli
The number of lobes from which a molar develops is the same as the
number of cusps
Maxillary molars have trifurcated (divided into three) roots
Mesiobuccal, distobuccal and lingual
Each root has one pulp canal
4. General Information
Molars are structured so that they are narrower (that is,
they converge) toward the posterior portion of the mouth.
Thus, the distal of the tooth is narrower than the mesial.
Because they have multicups, molars perform major tasks
of mastication and comminution by grinding a pulverizing
food.
6. Maxillary First Molars
Universal Number: 3, 14
Eruption Date: 7 years old
First Evidence of Calcification: birth
Crown Completion:2.5-3 years old
Root Completion: 9-10 years old
7. Maxillary First Molars
Function: mastication and comminution of food
Length of Crown: 7.5mm
Length of Root: 12mm buccal, 13mm lingual
Antagonists: mandibular first and second
molars
8. Maxillary First Molars
Identifying Features
Five cusps: Mesiobuccal, distobuccal, mesiolingual, distolingual,
cusp of Carabelli
Three roots: Mesiobuccal, distobuccal, lingual
Three pulp canals, one in each root
The Mesiobuccal root may have two pulp canals
Cusp of Carabelli, or fifth cusp, located on mesiolingual cusp, is a
nonfunctioning cusp
Largest and strongest of the maxillary teeth
9. Maxillary First Molars
Buccal Surface of the crown
There are two buccal cusps: Mesiobuccal and distobuccal
Two longer lingual cusp tips are visible
The buccal groove divides the two buccal cusps; it extends one-half the crown
length and terminates in a shallow depression
The mesial outline is straight
The mesial contact is two-thirds the distance from the cervical line
The distal side is convex
The distal contact area is in the middle of the surface
10. Maxillary First Molars
Buccal Surface of the Root
There are two buccal roots: Mesiobuccal and distobuccal
The Mesiobuccal root extends in a mesial direction for half of its length and
then curves distally
The distobuccal root is straight for half of its length, then curves mesially
The root trunk is about 4mm long before bifurcating
A shallow depression extends from the cervical line and terminates in a deep
groove at the bifurcation.
The lingual root extends between and above the buccal roots
11. Maxillary First Molars
Lingual Surface
Crown:
Three visible cusps: mesiolingual, distolingual, and cusp of Carbelli
Mesiolingual cusp about three-fifths the width of the crown
A cusp of Carabelli positioned on the mesiolingual cusp
A fifth cusp groove on mesiolingual cusp if fifth cusp is not present
A lingual groove dividing the two lingual cusps
Root:
A broad, tapered lingual root, the longest of the three roots, with a furrow or depression
A visible outline of both buccal roots
12. Maxillary First Molars
Mesial Surface
Crown:
Visible cusps: Mesiobuccal, mesiolingual, a cusp of Carabelli
A depression on the crown from the contact area to the root trunk
A mesial marginal ridge about one-fifth the distance from the cusp tips
Root:
Two visible roots: a broad, flat mesiobuccal root and a tapered lingual root
A depression on the lingual root
13. Maxillary First Molars
Distal Surface
Crown:
Visible buccal and occlusal surfaces
An almost straight cervical line
Root:
All three roots visible (only the border of the Mesiobuccal root
can be seen)
A depression from the cervical line to the distobuccal root
No concavity in the root bifurcation
14. Maxillary First Molars
Occlusal Surface
Dimensions that are wider from the buccal to the lingual than from
the mesial to the distal
Four functioning cusps and a small fifth cusp (in order of size):
mesiolingual, Mesiobuccal, distobuccal, distolingual, and cusp of
Carbelli
Grooves: buccal, central, transverse groove of the oblique ridge, and
distal oblique, the lingual and fifth cusp groove are visible from this
view
Fossae: central, distal linear, mesial triangular, distal triangular
16. Maxillary Second Molar
Universal Number: 2,15
Eruption Date: 12-13 years old
First Evidence of Calcification: 2.5-3 years old
Crown Completion:7-8 years old
Root Completion: 14-16 years old
17. Maxillary Second Molar
Function: mastication and comminution
Length of Crown: 7mm
Length of Root: 11mm buccal, 12mm lingual
Antagonists: mandibular second and third
molars
18. Maxillary Second Molar
Identifying Features
Four cusps: Mesiobuccal, distobuccal,
mesiolingual, distolingual
Three roots: Mesiobuccal, distobuccal, lingual
Three pulp canals: one in each root
19. Maxillary Second Molar
Maxillary second molar is similar to the maxillary first molar in
size, shape and function, but has the following differences:
Both the crown and root are slightly smaller
The second molar only has four cusps (no cusp of Carabelli)
The roots are not as divergent. They are closer together
The occlusal surface has more supplementary grooves
There is no transverse groove of the oblique ridge
23. Maxillary Second Molar
Occlusal Surface
Grooves: Buccal, lingual, distal oblique, and central
groove
Fossae: central, distal linear, distal triangular, and
mesial triangular
Cusps, in order of size: mesiolingual, Mesiobuccal,
distobuccal, and distolingual
27. Maxillary Third Molar
Universal Number: 1, 16
Eruption Date: 17-21 years old
First Evidence of Calcification: 7-9 years old
Crown Completion: 12-16 years old
Root Completion: 18-25 years old
28. Maxillary Third Molar
Function: mastication and comminution
Length of Crown: 6.5mm
Length of Root:11mm
Antagonists: Mandibular third molar
29. Maxillary Third Molar
Identifying Features
Often the crown is heart shaped
Fused roots (three roots)
May resemble first or second molar
30. Maxillary Third Molar
Clinical Considerations
Because of developmental variations, there is no standard
description for the maxillary third molars
When well-formed, they will be smaller than, but similar to,
the first molars in number of cusps and roots.
Usually, however, the roots are fused and the crowns will
have numerous supplemental (small, indistinct) grooves.
