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Permanent maxillary first molar
1. Presented by,
Dr. manjula marandi,
MDS Oral Pathology, Microbiology
and Forensic Odontology
The Permanent Maxillary First
Molar
2. Introduction
First permanent molar is present at the
center of the fully developed adult jaw
anteroposteriorly- corner stone of the dental
arch.
First permanent molar (mand & max) erupts
posterior to the second decidous molar, in
contact with it- so permanent molar is not a
succedaneous tooth, has no predecessor.
3. The Permanent Maxillary First Molar
Largest and strongest maxillary teeth- bulk
and anchorage in the jaws
The maxillary first molar is
the tooth located laterally (away from the
midline of the face) from both the maxillary
second premolars of the mouth but mesial
(toward the midline of the face) from
both maxillary second molars.
The function of this molar is similar to that of
all molars in regard to grinding being the
principal action during mastication,
commonly known as chewing.
5. Maxillary first molar
Crown – wider buccoligually (1mm) than
mesiodistally.
Four well developed functional cusp and one
supplemental cusp.
Supplemental cusp- cusp or tubercle of Carabelli,
Found lingual to the mesiolingual cusp.
Three roots- well separated and well developed
Lingual root- longest, tapered and smoothly
rounded.
Mesiobuccal root- broader buccolingually
Distobuccal root –smallest of the three, smoothly
7. The Buccal Aspect
Trapezoidal shape
Cervical line is the shorter of the uneven
sides
Parts of all 4 cusps visible
Portion of distal surface can be seen
because of the obtuse distobuccal line
angle
Mesiobuccal cusp broder of the buccal
cusps
Prominent buccal groove that
continues over from the occlusal surface
and terminates half distance to the
cervical line.
Cervical line does not have much
curvature from measial to distal
P
BD
8. Buccal Aspect
Root trunk –commom root
trunk.
Deep developmental
groove buccally on the root
trunk- starts at the
bifercation & progress
downward becomes
shallower until it terminates
in the shallow depression
at the cervical line.
Lingual root is the longest
& two buccal roots are
equal in length
10. Palatal Aspect
Outlines reversed from the
buccal aspect, still
trapezoidal.
Lingual cusps are only see
from the lingual aspect.
Mesiopalatal largest cusp
Distopalatal smallest cusp,
almost spheroidal
Lingual developmental
groove –starts approx at the
center of the lingual surface
mesiodistally, curves distally
as it crosses b/w the cusp and
11. Palatal Aspect
• There may be a cusp on the
palatal surface of the mesiopalatal
cusp.
This is a fifth cusp called the cusp of
Carabelli, which is visible in addition to
the four cusps on the occlusal surface
All three roots are visible lingual root
making up most of the foreground
Lingual root- conical, terminating in a
bluntly rounded apex
13. Mesial Aspect
Mesiobuccal and
mesiopalatal and fifth cusps
visible.
Mesiobuccal root hides the
distobuccal
root
Mesiolingual cusp is on a line
with the long axis of the lingual
root
Mesial marginal ridge
confluent with the mesiobuccal,
mesiopalatal cusp ridges is
irregular and curved cervically
14. Mesial Aspect
Cervical line irregular and
curves occlusally
The contact area at the
junction of the middle and
occlusal third, closer to
the buccal aspect Shallow
concavity just below the
contact area.
Level of bifurcation is a
little closer to the cervical
line than in the roots
buccaly.
LM
16. Distal Aspect
Basic outlines reverse from
mesial aspect
Distobuccal and
distopalatal cusps are seen
Marginal ridge dips sharply
cervically
More of occlusal surface
seen because of distal tilt of
crown.
Cervical line almost
straight
17. Distal Aspect
Distobuccal root is narrower
at its base than either of the
others
The buccal outline of the
distobuccal root lies entirely
within the confines of the
outline of the mesiobuccal
root.
Birfurcation is more apical
than either of the two areas
on the tooth
Area from cervical line to
birfurcation is 5mm or more
5mm
19. Occlusal Aspect
Crown- rhomboid, acute angles
mesiobuccal and distolingual,
obtuse angle mesiolingual and
distobuccal
Wider mesially than distally and
wider lingually than buccally
Four major cusp and a fifth
minor, small cusp on lingual
surface of the mesiolingual cusp
Mesiolingual cusp-largest in size
followed by
mesiobuccal,distolingual,
distobuccal and fifth cusp
Maxillary molar primary cusp
triangle- cusp outline,mesial
marginal ridge and oblique ridge
OCCLUSAL
ASPECT
B
P
D
20. Cusp size:
- Mesiopalatal: largest
- Mesiobuccal
- Distobuccal
- Distopalatal: smallest
Ridges:
- Mesial and distal marginal ridges and
oblique ridge
Fossae:
- Major: Central and Distal fossa
- Minor: Mesial and distal triangular
Grooves:
- Central, buccal and palatal
developmental groove
- Distal oblique groove
- Transverse groove
- Fifth cusp groove
- Supplemental grooves
Pit:
- Central Pit
22. The Root
Maxillary first molar has three roots; 2
buccal , 1 Palatal
Palatal root is long and slender
Mesiobuccal root broader, curves distally.
Distobuccal root narrow at base and a lot
straighter
Buccal roots are of equal size, smaller
than the palatal root
Level of bifurcation closer to the cervical
line mesially than distally
24. Questions?
Describe the occlusal aspect of permanent
maxillary first molar with diagram?
Write a short note on roots of permanent
maxillary first molar with diagram?
Describe in detail characteristic features of
permanent maxillary first molar with diagram?