Tooth Morphology
Mandibular
Molars
Crown & Bridge
Stage 3
Construct Crown & Bridge Structures 510B Ver2
Important Note
All notes for today’s lesson can be found in your
anatomy text book purchased in Stage 1:-
Anatomy of Orofacial Structures
Authors: Brand & Isselhard
All page numbers are from the 7th Edition
Outcomes for Today
At the end of today’s session you should
be able to:• Identify and describe Mandibular Molars
Mandibular Molars
Teeth begin to develop in the alveolar process during
the sixth week of fetal life. A tiny tooth bud forms
(tooth germ) where four or more growth centers are
present. From these growth centers developmental
lobes are formed. These lobes grow and develop
until they fuse together to form a tooth.
Mandibular Molars
Mandibular Molars have four lobes:
• Two on the buccal surface of a tooth
• Two on the lingual surface of a tooth
Exception: 1st molars may have a 5th or
minor lobe
Special note: 3rd molars can vary from 1-8
cusps
Mandibular Molars
All the lobes growth and partially fuse to form
the cusps of a molar. The formed cusps are
named according to location:• Mesiobuccal Cusp
• Distobuccal Cusp
• Mesial Lingual Cusp
• Distolingual Cusp
• Distal Cusp
Mandibular Molars
The permanent dentition has twelve molars
in total:• Six in the maxillary arch
• Six in the mandibular arch
The Mandibular Arch contains two:• 1st Molars
• 2nd Molars
• 3rd Molars
Mandibular
st
1
Molar
Mandibular 1st Molar
Buccal View
• Generally three flat buccal
cusps
Mandibular 1st Molar
Lingual View
• Lingual cusps are
almost equal in size
• Lingual cusps are
more pointed than
buccal cusps
Mandibular 1st Molar
Mesial and Distal View
• Buccal surface is convex and
tips lingually
• Mesial marginal ridge has a
prominent crest
• Distal marginal ridge is
bisected by distal marginal
groove
• Flat lingual surface
Mesial
Distal
Mandibular 1st Molar
Occlusal View
• Two transverse ridges are
present
• Mesial & distal profiles
straight, converging lingually
• Outline of crown is
rectangular in shape
• Wider mesiodistally than
buccolingually
Mandibular
nd
2
Molar
Mandibular 2nd Molar
Buccal View
• Similar to first molar,
but not as wide
mesiodistally
• Smaller crown overall
• Possible to have two
or three buccal cusps
Mandibular 2nd Molar
Lingual View
• Two lingual cusps are
nearly the same size
Mandibular 2nd Molar
Mesial and Distal View
• Mesial and distal profiles
are generally curved
• Mesial view very similar to
the 1st molar
• If the distal cusp is not
present, it looks very
different to the 1st molar
from the distal
Mesial
Distal
Mandibular 2nd Molar
Occlusal View
• Outline of crown is
rectangular in shape
• All four cusps are equal in
size when there is no 5th
cusp present
• Main occlusal grooves form a
cross (+) if there are only two
buccal cusps
Mandibular
rd
3
Molar
Mandibular 3rd Molar
Buccal View
• Smallest in width
• Distobuccal cusps much
shorter than mesiobuccal
Mandibular 3rd Molar
Lingual View
• Distolingual cusp usually
missing, but maybe present
• Pronounced distal
inclination of roots
Mandibular 3rd Molar
Mesial and Distal View
• Mesial and distal are the
same as 2nd molar
• Buccal and lingual
surfaces are convex
• Three roots are close
together and usually fused
Mesial
Distal
Mandibular 3rd Molar
Occlusal View
• Crown outline
more round
• Wrinkled
appearance with
irregular pattern
and numerous pits
Mandibular Molars
1st Molar
Buccal
2nd Molar
Lingual
Buccal
Occlusal
Mesial
Lingual
3rd Molar
Occlusal
Distal
Mesial
Lingual
Buccal
Occlusal
Distal
Mesial
Distal
Outcomes achieved
You should be able to:• Identify and describe Mandibular Molars