MORPHOLOGYOF

PERMANENT CANINES

Dr. Firas Alsoleihat, BDS, PhD Dental Morphology

Department of Conservative Dentistry

The permanent canines Eruption sequence

Lower before upper

Function No type traits Class traits

The most stable Longest & thickest roots LL Single conical cusp Only cusped teeth without

occlusal surface Support the arch and

facial musculature

Arch traits Upper larger than lower Smaller IC / MD proportion

in maxillary canine

The maxillary canine

Labial aspects Cusp tip is on a line bisecting the tooth MD Incisal outline has 2 sloping ridges

• Mesial ridge sloping less markedly and shorter than distal

Mesial HOC is close to the incisal margin Distal HOC is at the middle portion of the crown Mesial outline is slightly convex Mesial cusp slope might exhibit slight concavity Distal outline is markedly concave Distal cusp slope is straight or slightly convex CEJ is slightly convex incisally Labial surface

• Labial ridge• Slight depressions on either sides, but more distally

Root is long & narrow

The maxillary canine Lingual aspect

Crown & root narrower lingually Well-elevated marginal ridges (arch trait) Accentuated lingual cingulum – slightly

concave at midpoint (arch trait) Pronounced lingual ridge (arch trait) ML & DL fossae A lingual pit and/or developmental grooves

marking the inner boundaries of marginal ridges Mesial aspect

Cusp tip labial to a line bisecting the tooth LL Thick cervical third HOC is between cervical and middle thirds From HOC outline is straight toward cusp tip Lingual outline starts cervically convex

then slightly concave then convex again HOC is close to cervical line Thick incisal ridge LL (arch trait) Root is wide with a slight longitudinal

concavity and blunt apex

The maxillary canine

Distal aspect Deeper and longer longitudinal

concavity on the root

Incisal aspect Asymmetry

• Distal half is wider & has a concavity

on the labial outline• Mesial part of the labial outline is convex

Prominent convexity of the cingulum

Pulp Double convex lens shape in LL section,

widest near cervix Narrow in MD section

Maxillary Canine

The mandibular canine Narrower MD and LL (arch trait) Smaller MD/IC proportion (arch trait)

Labial surface• The crown length is equal or longer by 0.5 to 1 mm• The root is usually shorter but sometimes as long as the maxillary

canine. Cusp is not as long & pointed as in maxillary (arch trait) The labiolingual diameter of crown and root is usually a fraction

of a millimeter less. Mesio-distally it is narrower. Mesial cusp ridge is shorter and high adjacent to cusp tip Distal cusp ridge is low Incisal outline = 1/4 to 1/5 IC height Mesial outline is straight while distal is convex

• Both converge slightly toward the cervix Mesial HOC is just below MI angle while

DI angle is between incisal & middle thirds The crowns of the mandibular canines appear longer than maxillary

canines due to the narrowness of the crown mesiodistally and the height of the contact areas above the cervix.

The cusp angle is on a line with the center of the root, as on the maxillary canine

Root is conical with blunted root• Mesial inclination from cervix to apex• Crown appears tilted distally in relation to root long axis

The mandibular canine Lingual aspect

Marginal ridges, lingual ridge & cingulum are less prominent

ML & DL fossae are shallower Pits or grooves are rare Root narrower lingually than labially Distinct longitudinal depressions

extends down proximal surfaces• The lingual portion of the root is narrower relatively than that of

the maxillary canine. It narrows down to little more than half the width of the labial portion.

Mesial aspect Cusp tip with long axis of the tooth Cervical third is narrower HOC is just above CL &

entire labial outline is convex Root is narrower and root tip more pointed CL curves more toward the incisal portion than in the maxillary

canine. Mesial developmental depression is more pronounced than in The

max. canine incisal portion of the crown is thinner labiolingually, which allows

the cusp to appear more pointed and the cusp ridge to appear more slender.

The mandibular canine

Distal aspect Similar to mesial CL curves less toward the incisal portion than in

the maxillary canine.

Incisal aspect M & D halves are more nearly symmetrical Lingual outline is less round Less bulky appearance of the incisal edge The cusp tip and mesial cusp ridge are more

likely to be inclined in a lingual direction

Pulp Similar to maxillary canine

chronology

Maxillary Canine

First evidence of calcification:4-5mo

Enamel completed:6-7yr

Eruption:11-12yrRoot completed:13-15yr

Mandibular Canine

First evidence of calcification:4-5 mo

Enamel completed:6-7yr

Eruption:9-10yr

Root completed:12-14yr

Canine relationship

Class IClass IIClass III