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Maxillary Canine Principal Identifying Features

The “single” members of the dental arches.

The most stable teeth in the dental arches.

Their roots are the longest (16.2 mm) and thickest “labio-lingually”.

Well anchored in the alveolar bone last teeth to be lost.

They are referred to as the “corner stones” of the dental arches- help

to support the facial musculature.

Both maxillary and mandibular canines have the canine eminence

which is the bone ridge over the labial portions of the roots.

Function :

a) Anchorage in the bone

b) Cosmetic value.

c) Ensures normal facial expression at the corners of the mouth.

Chronology

First evidence of calcification 4-5 m.

Crown completed 6-7 y.

Eruption 11-12 y

Root completion 13-15 y

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Labial aspect

Geometric out line

Trapezoidal.

The mesial outline

Convex from the cervix to the center of the mesial contact

area.

The distal outline

Usually concave between the cervical line and the distal

contact area.

Contact areas

Mesially: at the junction of middle and incisal thirds

Distally: is usually at the center of the middle third of the crown.

The cusp:

The cusp tip is on a line with the center of the root. The cusp has a

mesial slope and a distal slope, the mesial slope being the shorter of

the two. Both slopes show a tendency toward concavity

Surface description

The labial ridge:

The middle labial lobe shows much greater development than the

other lobes. This produces a ridge on the labial surface of the crown.

The labial surface of the crown is smooth, with shallow

depressions mesially and distally, dividing the three labial lobes.

Cervical line

Convex root wise.

The root

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Appears slender, conical in form with a bluntly pointed apex. Mostly

curved distally in the apical third.

The labial surface of the root is smooth and convex at all points

Lingual Aspect

The crown and root are narrower lingually than labially.

The cingulum is large and pointed like a small cusp

Strongly developed marginal ridges:

Well-developed lingual ridge is seen that is

confluent with the cusp tip; this extends to a point

near the cingulum.

Shallow concavities are evident between this ridge

and the marginal ridges. They are called mesial and

distal lingual fossae

The lingual portion of the root of is narrower than the labial portion.

Mesial aspect

Greater labiolingual measurement than any of the other

anterior teeth

The crown is wedge-shaped, the greatest measurement

being at the cervical third and the wedge point being

represented by the tip of the cusp.

Labial outline is convex with the crest of curvature at

the cervical third

The lingual outline is convex line describing the

cingulum, which convexity straightens out as the

middle third is reached, becoming convex again in the

incisal third

A line bisecting the cusp is labial to a line bisecting the root

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Cervical outline: curved incisally

The outline of the root from this aspect is conical, with a tapered or

bluntly pointed apex with a shallow developmental depression.

Distal Aspect

The same form as the mesial aspect, with the following

variations:

the cervical line exhibits less curvature

the distal marginal ridge is heavier and more irregular

in outline;

The developmental depression on the distal side of the

root is deeper.

Incisal Aspect

Diamond in shape

The labiolingual dimension is greater than the mesiodistal.

The labial surface wider than the lingual

surface

The tip of the cusp is labial to the center of

the crown labiolingually and mesial to the

center mesiodistally.

The labial ridge is very noticeable labially

from the incisal aspect.

The cingulum development makes up the cervical third of the crown

lingually.

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Variations and Anomalies:

a) Crown form does not vary widely, although the sharpness of the

cusp tip has considerable range.

b) b. On rare occasions, the lingual surface may exhibit a tubercle

which is located near the most incisal level of the cingulum. When

a tubercle is present, a lingual pit is often associated with it.

c) c. Root form is subject to variations. There may be several

curvatures along its length. If curved in the apical third, the

deflection is most commonly to the distal.

d) d. Since the maxillary canine normally erupts after the maxillary

premolars, its space is sometimes partially closed. It may then

erupt well to the labial or lingual of the other teeth, or not erupt at

all, in which case it is considered to be impacted.

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Mandibular Canine

Principal Identifying Features

The mandibular canine crown is narrower mesiodistally than that of

the maxillary canine

-The root is somewhat shorter. The labiolingual diameter of crown

and root is smaller

-The lingual surface of the crown is smoother, with less cingulum

development and less bulk to the marginal ridges.

-The cusp of the mandibular canine is not as well developed as that of

the maxillary canine, and the cusp ridges are thinner labiolingually.

Usually the cusp tip lies lingual to the line, as with the mandibular

incisors.

Chronology

First evidence of calcification 4-5 m.

Crown completed 6-7 y.

Eruption 9-10 y

Root completion 12-14 y

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Labial Aspect

Less mesio-distal dimensions than those of the maxillary canine.

The crowns of the mandibular canines appear longer; the effect of

greater length is increased by:

a) The narrowness of the crown mesiodistally

b) The height of the contact areas above the cervix.

The mesial outline

Nearly straight with the mesial outline of the root, with the mesial

contact area being.

The distal outline

Convex inciso-cervical.

Contact areas

Mesially: near the mesioincisal angle “at the

middle of the incisal third”.

Distally: at the junction between middle and incisal

thirds.

The cusp:

The cusp angle is on a line with the center of the

root, as on the maxillary canine. The mesial cusp ridge is shorter.

The cervical line:

Semicircular curvature apically.

The root

The mandibular canine root is shorter by l or 2 mm on average than

that of the maxillary canine, and its apical end is more sharply

pointed.

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Lingual Aspect

The lingual surface of the crown of the mandibular

canine is flatter, simulating the lingual surfaces of

mandibular incisors

The lingual surface of the crown is smooth and regular;

the cingulum is smooth and poorly developed. The

marginal ridges are less distinct, the lingual ridge is

shallow except toward the cusp tip, where it is raised.

The lingual portion of the root is narrower relatively

than that of the maxillary canine.

Mesial Aspect

The mandibular canine has less curved labial outline while

the lingual outline of the crown is curved in the same

manner as that of the maxillary canine; as the cingulum is

not as pronounced, and the incisal portion of the crown is

thinner labiolingually, which allows the cusp to appear

more pointed.

The tip of the cusp is more nearly lingual over the root

The cervical line curves more toward the incisal portion

The roots of the two canines are similar but more pointed

root tip on the mandibular canine.

The developmental depression mesially on the root of the mandibular

canine is more pronounced

M

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Distal Aspect

Little difference from the distal aspect can be seen

between mandibular and maxillary canines; contact

area position, less curvature of the cervical line, and

deeper depression on the root surface.

Incisal Aspect

The outlines of the crowns of mandibular and maxillary canines from

the incisal aspect are often similar

The main differences to be noted are as follows:

The mesiodistal dimension of the mandibular

canine is less than the labiolingual dimension.

A similarity is evident in this.

The cusp tip and mesial cusp ridge are more

likely to be inclined in a lingual direction in the

mandibular canine.

Variations and Anomalies

a) Crown form is not greatly variable.

b) Irregularly curved roots ate occasionally seen, and bifurcated roots,

with labial and lingual branches, are also possible.