Human dentition Dr. Hazem Al Ajrami First Year in Dentistry First Semester by lama el banna Al-Azhar University - Gaza lecture 7

2. College of DentistryCollege of Dentistry
Human Dentition IHuman Dentition I
Maxillary CanineMaxillary Canine
Dr. Hazem Al AjramiDr. Hazem Al Ajrami

3. General featuresGeneral features
The maxillary and mandibular canines bear aThe maxillary and mandibular canines bear a
close resemblance to each other, and theirclose resemblance to each other, and their
functions are closely related. The four canines arefunctions are closely related. The four canines are
placed at the "corners" of the mouth, andplaced at the "corners" of the mouth, and
therefore to as the CORNER STONES of thetherefore to as the CORNER STONES of the
mouth, each one the third tooth from the medianmouth, each one the third tooth from the median
line, right and left, in the maxilla and mandible.line, right and left, in the maxilla and mandible.
They are the longest teeth in the mouth; theThey are the longest teeth in the mouth; the
crowns are usually as long as those of thecrowns are usually as long as those of the
maxillary central incisors and the single roots aremaxillary central incisors and the single roots are
longer than those of any of the other teeth.longer than those of any of the other teeth.

4.  The middle labial lobes have been highlyThe middle labial lobes have been highly
developed incisally into strong well-formeddeveloped incisally into strong well-formed
cusps. Crowns and roots are markedly convexcusps. Crowns and roots are markedly convex
on most surfaces.on most surfaces.
 The shape of the crowns, with their singleThe shape of the crowns, with their single
pointed cusps, their locations in the mouth,pointed cusps, their locations in the mouth,
and the extra anchorage furnished by the long,and the extra anchorage furnished by the long,
strongly developed roots, makes these caninesstrongly developed roots, makes these canines
resemble those of the Carnivora. Thisresemble those of the Carnivora. This
resemblance to the prehensile teeth of theresemblance to the prehensile teeth of the
Carnivora gives rise to the termCarnivora gives rise to the term canine.canine.

5. Because of the labiolingual thickness ofBecause of the labiolingual thickness of
crown and root and the anchorage in thecrown and root and the anchorage in the
alveolar process of the jaws, these teeth arealveolar process of the jaws, these teeth are
perhaps the most stable in the mouth. Theperhaps the most stable in the mouth. The
crown portions of the canines are shaped in acrown portions of the canines are shaped in a
manner that promotes cleanliness. This self-manner that promotes cleanliness. This self-
cleansing quality, along with the efficientcleansing quality, along with the efficient
anchorage in the jaws, tends to preserve theseanchorage in the jaws, tends to preserve these
teeth throughout life. When teeth are lost, theteeth throughout life. When teeth are lost, the
canines are usually the last ones to go.canines are usually the last ones to go.

6.  They are very valuable teeth, when consideredThey are very valuable teeth, when considered
either as units of the natural dental arches or aseither as units of the natural dental arches or as
possible assistants in stabilizing replacements ofpossible assistants in stabilizing replacements of
lost teeth in prosthetic procedures.lost teeth in prosthetic procedures.
 Both maxillary and mandibular canines haveBoth maxillary and mandibular canines have
another quality that must not be overlooked: Theanother quality that must not be overlooked: The
positions and forms of these teeth and theirpositions and forms of these teeth and their
anchorage in the bone, along with the bone ridgeanchorage in the bone, along with the bone ridge
over the labial portions of the roots, called theover the labial portions of the roots, called the
canine eminence, have a cosmetic value.canine eminence, have a cosmetic value.

9.  They help to form a foundation that ensuresThey help to form a foundation that ensures
normal facial expression at the "corners" of thenormal facial expression at the "corners" of the
mouth. Loss of all of these teeth makes itmouth. Loss of all of these teeth makes it
extremely difficult, if not impossible, to makeextremely difficult, if not impossible, to make
replacements that will restore that naturalreplacements that will restore that natural
appearance of the face for any length of time.appearance of the face for any length of time.
 It would therefore be difficult to place a valueIt would therefore be difficult to place a value
on the canines, their importance being madeon the canines, their importance being made
manifest by their efficiency in function, theirmanifest by their efficiency in function, their
stability, and their help in maintaining naturalstability, and their help in maintaining natural
facial expression.facial expression.

11. In function, the canines support the incisorsIn function, the canines support the incisors
and premolars, since they are located betweenand premolars, since they are located between
these groups. The canine crowns have somethese groups. The canine crowns have some
characteristics of functional form which willcharacteristics of functional form which will
bear a resemblance to incisor form, and somebear a resemblance to incisor form, and some
which resemble the premolar form. They helpwhich resemble the premolar form. They help
holding and tearing the food materials.holding and tearing the food materials.

12. The Maxillary CanineThe Maxillary Canine

13.  The crown and root are narrow mesio-distallyThe crown and root are narrow mesio-distally
than those of a maxillary central incisor. Thethan those of a maxillary central incisor. The
cervico-incisal length of the crown is muchcervico-incisal length of the crown is much
larger on a maxillary canine than any otherlarger on a maxillary canine than any other
anterior teeth, with the exception of theanterior teeth, with the exception of the
maxillary central incisor.maxillary central incisor.
 The mesial half of the crown of this toothThe mesial half of the crown of this tooth
resembles a portion of an incisor and contactresembles a portion of an incisor and contact
with the lateral incisor.with the lateral incisor.
 The distal half resembles a portion of premolarThe distal half resembles a portion of premolar
and contacts first premolarand contacts first premolar

14.  It is apparent that the construction of this toothIt is apparent that the construction of this tooth
has reinforcement, labiolingually, to offsethas reinforcement, labiolingually, to offset
directional lines of the force brought against itdirectional lines of the force brought against it
when in use. The incisional portion is thickerwhen in use. The incisional portion is thicker
labiolingually than that of either the maxillarylabiolingually than that of either the maxillary
central or the lateral incisor.central or the lateral incisor.
 The labiolingual measurement of the crown isThe labiolingual measurement of the crown is
about 1 mm. greater than that of the maxillaryabout 1 mm. greater than that of the maxillary
central incisor. The mesiodistal measurementcentral incisor. The mesiodistal measurement
is approximately 1 mm. less.is approximately 1 mm. less.

15.  Universal Numbering System:Universal Numbering System:
6 and 116 and 11
 Palmer Notation System:Palmer Notation System:
 FDI Numbering System:FDI Numbering System:
13 and 2313 and 23
33 andand 33

16.  Chronology:Chronology:
A.A. First evidence of calcification:First evidence of calcification: 44 toto 55 months.months.
B.B. Enamel completed:Enamel completed: 66 toto 77 years.years.
C.C. Eruption:Eruption: 1111 -- 1212 years.years.
D.D. Root completed:Root completed: 1414 -- 1515 years.years.

17. Cervico-
Incisal
Length of
Crown
Length of
Root
Mesiodistal
Diameter of
Crown
Mesiodistal
Diameter of
Crown at Cervix
Maxillary Canine 10 17 7.5 5.5

18. Labio-lingual
Diameter of
Crown
Labio-lingual
Diameter of
Crown at
Cervix
Curvature of
Cervical Line
(Mesial)
Curvature of
Cervical Line
(Distal)
Maxillary Canine 8 7 2.5 1.5

19. Labial AspectLabial Aspect
 The crown and root are narrower mesiodistallyThe crown and root are narrower mesiodistally
than those of the maxillary central incisor.than those of the maxillary central incisor.
 The difference is about 1 mm. in most mouths.The difference is about 1 mm. in most mouths.
 The cervical line labially is convex, with theThe cervical line labially is convex, with the
convexity toward the root portion.convexity toward the root portion.

20. MesialDistal

21.  TheThe mesial outlinemesial outline of the crown may be convexof the crown may be convex
from the cervix to the center of the mesialfrom the cervix to the center of the mesial
contact area, or the crown may exhibit a slightcontact area, or the crown may exhibit a slight
concavity above the contact area from the labialconcavity above the contact area from the labial
aspect. The center of theaspect. The center of the contact areacontact area mesiallymesially
is approximately at the junction of middle andis approximately at the junction of middle and
incisal thirds of the crown.incisal thirds of the crown.
 TheThe distal outlinedistal outline of the crown is shorter andof the crown is shorter and
usually concave between the cervical line andusually concave between the cervical line and
the distal contact area. The distalthe distal contact area. The distal contact areacontact area
is usually at the center of the middle third of theis usually at the center of the middle third of the
crown. The two levels of contact areas mesiallycrown. The two levels of contact areas mesially
and distally should be noted.and distally should be noted.

22. Unless the crown has been worn unevenly,Unless the crown has been worn unevenly,
the cusp tip is on a line with the center of thethe cusp tip is on a line with the center of the
root. The cusp has a mesial slope and a distalroot. The cusp has a mesial slope and a distal
slope, the mesial slope being the shorter of theslope, the mesial slope being the shorter of the
two. The mesial slope shows tendency towardstwo. The mesial slope shows tendency towards
concavity, while the distal slope showsconcavity, while the distal slope shows
tendency towards convexity, before wear hastendency towards convexity, before wear has
taken place. These depressions aretaken place. These depressions are
developmental in character.developmental in character.

23. The labial surface of the crown is smooth,The labial surface of the crown is smooth,
with no developmental lines of note exceptwith no developmental lines of note except
shallow depressions mesially and distally,shallow depressions mesially and distally,
dividing the three labial lobes. The middledividing the three labial lobes. The middle
labial lobe shows much greater developmentlabial lobe shows much greater development
than the other lobes. This produces a labialthan the other lobes. This produces a labial
ridge incisocervically near the center of theridge incisocervically near the center of the
crown. It is prominent in the middle andcrown. It is prominent in the middle and
incisal thirds.incisal thirds.

24. This ridge is responsible for the greatestThis ridge is responsible for the greatest
mesiodistal convexity by the labial surface ofmesiodistal convexity by the labial surface of
the canine. A line drawn over the crest of thisthe canine. A line drawn over the crest of this
ridge, from the cervical line to the tip of theridge, from the cervical line to the tip of the
cusp, is a curved one inclined mesially at itscusp, is a curved one inclined mesially at its
center. All areas mesial to the contrast of thiscenter. All areas mesial to the contrast of this
ridge exhibit convexity. Distally to the labialridge exhibit convexity. Distally to the labial
ridge, there is a tendency toward concavity atridge, there is a tendency toward concavity at
the cervical third of the crown, althoughthe cervical third of the crown, although
convexity is noted elsewhere in all areasconvexity is noted elsewhere in all areas
approaching the labial ridge.approaching the labial ridge.

25. The rootThe root of the maxillary canine appearsof the maxillary canine appears
slender from the labial aspect when comparedslender from the labial aspect when compared
with the bulk of the crown: it is conical inwith the bulk of the crown: it is conical in
form with a bluntly pointed apex. Thisform with a bluntly pointed apex. This
curvature may be in a mesial or distal directioncurvature may be in a mesial or distal direction
but mostly to abut mostly to a distal directiondistal direction. The labial. The labial
surface of the root is smooth and convex at allsurface of the root is smooth and convex at all
points.points.

26. Palatal AspectPalatal Aspect
 The crown and root are narrower palatally thanThe crown and root are narrower palatally than
labially.labially.
 The cervical line from this aspect is lessThe cervical line from this aspect is less
convex than that of the labial aspect or evenconvex than that of the labial aspect or even
straight.straight.
 The cingulum is large, and in some instancesThe cingulum is large, and in some instances
is pointed like a small cusp. Incisal to theis pointed like a small cusp. Incisal to the
cingulum, is the concavity of the palatal fossa.cingulum, is the concavity of the palatal fossa.

27.  The mesial and distal marginal ridges areThe mesial and distal marginal ridges are
strongly developed.strongly developed.
 Very often a well developed palatal ridge isVery often a well developed palatal ridge is
seen extending from the cusp tip to a pointseen extending from the cusp tip to a point
near the cingulum.near the cingulum.
 Two shallow palatal fossae are locatedTwo shallow palatal fossae are located
between two marginal ridges and the palatalbetween two marginal ridges and the palatal
ridge are termed distopalatal and mesiopalatalridge are termed distopalatal and mesiopalatal
fossae.fossae.

28. Palatal ridge
Mesiopalatal fossae Distopalatal fossae

29.  The palatal portion of the root is narrower thanThe palatal portion of the root is narrower than
the labial portion. Because of this formation,the labial portion. Because of this formation,
much of the mesial and distal surface of themuch of the mesial and distal surface of the
root is visible from the palatal aspect.root is visible from the palatal aspect.
 Developmental depressions mesially andDevelopmental depressions mesially and
distally may be seen on most of these roots,distally may be seen on most of these roots,
extending most of the root length. The palatalextending most of the root length. The palatal
ridge of the root is rather narrow, but it isridge of the root is rather narrow, but it is
smooth and convex at all points from thesmooth and convex at all points from the
cervical line to the apical end.cervical line to the apical end.

30. Mesial AspectMesial Aspect
 The mesial aspect of the maxillary canineThe mesial aspect of the maxillary canine
presents the outline of the functional form ofpresents the outline of the functional form of
an anterior tooth. It shows greater bulkan anterior tooth. It shows greater bulk
generally, however, and greater labiopalatalgenerally, however, and greater labiopalatal
measurement than any of the other anteriormeasurement than any of the other anterior
teeth.teeth.
 The outline of the crown isThe outline of the crown is wedge-shapedwedge-shaped, the, the
greatest measurement being at the cervicalgreatest measurement being at the cervical
third and the wedge point being represented bythird and the wedge point being represented by
the tip of the cusp.the tip of the cusp.

32. The curvature of the crown below theThe curvature of the crown below the
cervical line labially and palatally correspondscervical line labially and palatally corresponds
in extent to the curvature of maxillary centralin extent to the curvature of maxillary central
and lateral incisors. Nevertheless, the crest ofand lateral incisors. Nevertheless, the crest of
that curvature is found at a level more incisal,that curvature is found at a level more incisal,
since the middle labial and the palatal lobessince the middle labial and the palatal lobes
are more highly developedare more highly developed..

33.  Below the cervical third of the crown, theBelow the cervical third of the crown, the
labial facelabial face may be presented by a line onlymay be presented by a line only
slightly convex from the crest of curvature atslightly convex from the crest of curvature at
the cervical third to the tip of the cusp. Thethe cervical third to the tip of the cusp. The
line usually becomes straighter as itline usually becomes straighter as it
approaches the cusp.approaches the cusp.
 The entireThe entire labial outlinelabial outline from the mesialfrom the mesial
aspect exhibits more convexity from theaspect exhibits more convexity from the
cervical line to the cusp tip than the maxillarycervical line to the cusp tip than the maxillary
central incisor.central incisor.

34.  The palatal outlineThe palatal outline of the crown from theof the crown from the
mesial aspect may be represented by a convexmesial aspect may be represented by a convex
line describing the cingulum, which convexityline describing the cingulum, which convexity
straightens out as the middle third is reached,straightens out as the middle third is reached,
becoming convex again in the incisal thirdbecoming convex again in the incisal third..
 The cervical lineThe cervical line which outlines the base ofwhich outlines the base of
the crown from this aspect curves toward thethe crown from this aspect curves toward the
cusp, on the average, approximately 2.5 mm.cusp, on the average, approximately 2.5 mm.
(cementoenamel junction).(cementoenamel junction).

35.  The outline of the root from this aspect isThe outline of the root from this aspect is
conical, with a tapered or bluntly pointed apex.conical, with a tapered or bluntly pointed apex.
The root may curve labially toward the apicalThe root may curve labially toward the apical
third.third.
 The position of the tip of the cusp in relation toThe position of the tip of the cusp in relation to
the long axis of the root is different from thatthe long axis of the root is different from that
of maxillary central and lateral incisors. Aof maxillary central and lateral incisors. A
line bisecting the cusp is labial to a lineline bisecting the cusp is labial to a line
bisecting the root. Lines bisecting the roots ofbisecting the root. Lines bisecting the roots of
central and lateral incisors also bisect thecentral and lateral incisors also bisect the
incisal edges.incisal edges.

36.  The mesial surface of the root appears broadThe mesial surface of the root appears broad
labiopalatal at the cervical and middle thirdslabiopalatal at the cervical and middle thirds
then it tapers gradually to a sharp or slightlythen it tapers gradually to a sharp or slightly
blunt apex, with a shallow developmentalblunt apex, with a shallow developmental
depression for part of the root length.depression for part of the root length.
 Developmental depressions on the heavy rootsDevelopmental depressions on the heavy roots
help to anchor the teeth in the alveoli and helphelp to anchor the teeth in the alveoli and help
to prevent rotation and displacement.to prevent rotation and displacement.

37. Distal AspectDistal Aspect
The distal aspect of the maxillary canineThe distal aspect of the maxillary canine
shows somewhat the same form as the mesialshows somewhat the same form as the mesial
aspect, with the following variations:aspect, with the following variations:
1.1. The cervical line exhibits less curvatureThe cervical line exhibits less curvature
toward the cusp tip.toward the cusp tip.
2.2. The distal marginal ridge is heavier and moreThe distal marginal ridge is heavier and more
irregular in outline.irregular in outline.
3.3. The surface is more concavity usually aboveThe surface is more concavity usually above
the contact area, and the developmentalthe contact area, and the developmental
depression on the distal side of the root isdepression on the distal side of the root is
more pronounced.more pronounced.

39. Incisal AspectIncisal Aspect
 The labiopalatal dimension is greater than theThe labiopalatal dimension is greater than the
mesiodistal dimension due to the existence ofmesiodistal dimension due to the existence of
bulky cingulum and the labial and palatalbulky cingulum and the labial and palatal
ridges.ridges.
 The cusp tipThe cusp tip is labial to the center of theis labial to the center of the
crown labiopalatally and mesial to the centercrown labiopalatally and mesial to the center
mesiodistally.mesiodistally.

41.  The labial and palatal ridges are located at theThe labial and palatal ridges are located at the
center of labial and palatal surfaces. The twocenter of labial and palatal surfaces. The two
shallow palatal fossae are seen lateral to theshallow palatal fossae are seen lateral to the
palatal ridge.palatal ridge.
 The ridge of the middle labial lobe is veryThe ridge of the middle labial lobe is very
noticeable labially from the incisal aspect. Itnoticeable labially from the incisal aspect. It
attains its greatest convexity at the cervicalattains its greatest convexity at the cervical
third of the crown, becoming broader andthird of the crown, becoming broader and
flatter at the middle and incisal thirds.flatter at the middle and incisal thirds.
 The cingulum is large and is located at theThe cingulum is large and is located at the
center mesiodistally. The cingulum showscenter mesiodistally. The cingulum shows
greater development than that of the centralgreater development than that of the central
incisor.incisor.

42. As was mentioned in maxillary lateralAs was mentioned in maxillary lateral
incisor lecture, there are two types ofincisor lecture, there are two types of
maxillary lateral incisors, some resemblingmaxillary lateral incisors, some resembling
canines from the incisal aspect and somecanines from the incisal aspect and some
resembling central incisors. The latter areresembling central incisors. The latter are
supposed to be in the majority. Naturally, thesupposed to be in the majority. Naturally, the
lateral incisors that resemble canines arelateral incisors that resemble canines are
relatively wide labiolingually and thoserelatively wide labiolingually and those
resembling central incisors are narrow in thatresembling central incisors are narrow in that
direction.direction.

43.  The incisal aspect of most canines, maxillaryThe incisal aspect of most canines, maxillary
or mandibular, may be outlined in many casesor mandibular, may be outlined in many cases
by a series of arcs.by a series of arcs.
 The mesial slope is shorter than the distalThe mesial slope is shorter than the distal
slope.slope.

44. Thank YouThank You