morphology of permanent canines
TRANSCRIPT
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