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MORPHOLOGYOF
PERMANENT CANINES
Oral HistologyDent 201
Summer semester 2005/2006
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 Greater 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
• MI angle is higher and more rounded than DI angle Mesial HOC is close to the incisal margin Distal HOC is at the middle portion of the crown Mesial outline is slightly convex Distal outline is markedly convex CEJ is slightly convex incisally Labial surface
• Labial ridge
• Slight depressions on either sides 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 3 distinct lobes
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 Cusp is not as long & pointed as in maxillary (arch trait) Mesial cusp ridge is 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 3 lobes & 2 depressions on the labial surface 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 are shallower Pits or grooves are rare Root narrower lingually than labially Distinct longitudinal depressions
extends down proximal surfaces 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
The mandibular canine
Distal aspect Similar to mesial
Incisal aspect M & D halves are more nearly symmetrical Lingual outline is less round Less bulky appearance of the incisal edge Vertical lobe grooves are less marked
Pulp Similar to maxillary canine
Canine relationship
Class IClass IIClass III