Download Mesial aspect

MANDIBULAR
CANINE
(8)
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Prof. A. El-Sahn
CHRONOLOGY
 Initial calcification
:
4 – 5 month after birth
 Completion of crown:
6 – 7 years
 Eruption
9 – 10 years
:
 Completion of root :
12 – 14 years
Prof. A. El-Sahn
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43

The mandibular canine is the third tooth
from the midline of the mandible.

It closely resembles the upper canine.
Prof. A. El-Sahn
+0.4 mm.
-0.8 mm.
Its features are less well developed
than those of upper canine.
Its crown appears long and narrow compared
with that of upper canine.
It is actually 0.4 mm. longer and 0.8 mm.
narrower.
Prof. A. El-Sahn
Labial aspect
The crown
The mesial outline:
Is nearly straight from the cervical line to
the mesial contact area, then continues to
the cusp slope.
It is nearly in line with the mesial side of
the root and does not project or bulge
beyond the root outline.
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Prof. A. El-Sahn
Labial aspect
The distal outline:
Is slightly concave in the cervical
third, then, it becomes convex incisally.
It projects beyond the root outline. The
distal outline is shorter than the mesial
outline.
From this aspect the crown appears to be
tilted or bent distally due to the difference
in mesial and distal outlines.
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Prof. A. El-Sahn
Labial aspect
The crown
Incisal outline:
The cusp tip is usually on the root
axis line.
Its slopes form a more obtuse
angle than those of upper canine.
The cusp is less pointed than that
of upper canine.
Prof. A. El-Sahn
Incisal outline : (Cont.)
 The mesial slope of the cusp
is shorter than the distal slope,
more so than on maxillary canine.
 The mesial cusp slope is also
in a more nearly horizontal plane
compared to the longer distal
cusp slope, which slopes more
severely in an apical direction. M
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Prof. A. El-Sahn
Labial aspect
Contact areas:
Mesial In the incisal third just below
the mesioincisal angle.
Distal At the junction of the middle
and incisal thirds, more cervically
located than the mesial contact area.
Prof. A. El-Sahn
Labial aspect
Cervical line:
It has a semicircular curvature root ward.
Morphology of the labial surface
The labial surface is smooth and
convex.
It often shows a labial ridge, which
is not as prominent as on the upper
canine.
Prof. A. El-Sahn
Morphology of the labial surface cont.
 Shallow vertical depressions
may be present on either side of
the labial ridge in the incisal third.
 The incisal third of the crown is
slightly flattened mesial and distal
to the labial ridges.
Prof. A. El-Sahn
-0.6 mm -2 mm.
The root
 The root is shorter than that
of the upper canine by 0.6 mm
to 2 mm.
 Its apical end is more sharply pointed.
 Its apical end is more often straight than
curving toward mesial or distal sides.
 The root is convex on the labial surface.
Prof. A. El-Sahn
Lingual aspect
The crown
The crown taper toward
the lingual surface.
The lingual surface of the
crown resembles those of
the lower incisors in being
smooth, However;
A faint lingual ridge is running from the cusp
tip to the cingulum.
Prof. A. El-Sahn
Lingual aspect
The crown cont.
 The cingulum is poorly developed
 The marginal ridges are not prominent.
 The mesial marginal ridge is longer
and straighter than the shorter, more
elevated and curved distal marginal ridge.
Prof. A. El-Sahn
The Root
 The lingual portion of the
root is narrower than that of
the upper canine.
 The lingual surface of the
root is convex.
Prof. A. El-Sahn
Mesial aspect
The Crown
 The mesial surface of the
crown is wedge-shaped.
 The crown mesially is longer
than of upper canine.
 The crown is narrower
labiolingually than the upper
canine (by 0.4 mm).
Prof. A. El-Sahn
Mesial aspect
 The labial outline has less
curvature than that of upper
canine with very little crest of
curvature directly above the
cervical line.
The lingual outline is similar
to that of the upper canine. The cingulum is not
prominent.
 Incisally: the incisal portion of the crown is
thinner labiolingually.
Prof. A. El-Sahn
Mesial aspect
 The cusp appears more
pointed.
 The tip of the cusp is most
often located slightly lingual
to the root axis line, but it may
be centered over it.
Cervical line:
Curves more incisally than does the cervical
line on upper canine.
Prof. A. El-Sahn
The Root
 The root surface is similar to that
of the upper canine from the mesial
aspect except:
 The root tip is more pointed than
that of upper canine.
 The developmental depression
mesially is more pronounced than
that on upper canine.
Prof. A. El-Sahn
Distal aspect
 The general shape from the
distal aspect is similar to the
shape from the mesial aspect.
 The distoincisal angle is
slightly more lingual in position
than the cusp tip because of the
distolingual twist of the crown
to the lower lateral incisors).
(similar
 The cervical line curvature is less on the distal
surface than on the mesial surface.
Prof. A. El-Sahn
The Root
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The vertical developmental depression on the
distal side of the root is often deeper than the
depression on the mesial side.
Prof. A. El-Sahn
Incisal aspect
 The outline of lower canine
from the incisal aspect is often
similar to that of upper canine.
 The labiolingual dimension
of the crown is longer than the
mesiodistal dimension similar to
upper canine.
The cusp tip is more likely to
be inclined lingually.
Prof. A. El-Sahn
Incisal aspect
Labially, the mesiolabial outline is more convex
while the distolabial outline is flat or concave
The distal cusp slope is directed
slightly lingually from the cusp
tip, which places the distoincisal
angle in a lingual position to the
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cusp tip.
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Prof. A. El-Sahn
-This lingual placement of the distoincisal angle
gives the incisal part of the crown a distolingual
twist like lower lateral incisor. This twist matches
closely the curvature of the dental
arch.
The crown tapers lingually and the cingulum is
represented by a curved line.
Prof. A. El-Sahn
Thank you
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