The Permanent Maxillary Canine Notes

The Permanent Maxillary Canine

There are four canines in the oral cavity with two each in the maxilla and the mandible. They are the third teeth from the midline and are present between the lateral incisor and the first premolar. The canines in the maxilla and the mandible resemble each other and are referred to as the corner stones ofthe dental arch.
The single pointed cusps of the canine make it the most efficient in cutting and shearing of food. The canine eminence which is the bony ridge over the labial portion of the root has high aesthetic value. The self-cleansing property of the canine and the anchorage helps in preserving this tooth throughout life.

Read And Learn More: Oral Anatomy Notes

Class Traits Of Canines

The characteristics that are common to all the canines are referred to as class traits of canines:

• Canines develop from four lobes; three labial and one lingual.
• Canines have a well-developed middle lobe.
• The crown is wider labiolingually than mesiodistally.
• The pointed cusp tip is due to the union of the mesial and the distal incisal ridges also called slopes; the distal cusp ridge/slope is longer than the mesial cusp ridge/slope.
• On the buccal aspect, the labial ridge extends from the cusp tip to the cervical line.
• On the lingual aspect, a well-developed cingulum and a lingual fossa is present.
• A lingual ridge divides the lingual fossa into the mesial and distal.
• The distal contact area is more cervically placed compared to the mesial contact area.
• Canines are the longest teeth in the dental arch and most suitable for anchorage.
• The developmental depressions on the root mesially and distally help in secure anchorage in the jaw.

The Maxillary Canine

From the labial aspect mesial half of the canine is similar to an incisor and the distal half to a premolar from the labial aspect.

The canine is 1 mm greater labiolingually and 1 mm smaller mesiodistally than the maxillary central incisor. The cingulum is well developed compared to the central incisor.

The morphology of this tooth will be described from the labial, lingual, mesial, distal and incisal aspects. The nomenclature, chronology and the measurement of the maxillary canine are given below

Nomenclature: Maxillary canine:

Maxillary canine: Chronology and measurements:

labial aspect:

Features of the crown:

Shape and surface:

• The surface is smooth and convex.
• The middle lobe is well-developed, And shallow depressions are present mesial and distal to the middle Lobe dividing the three labial lobes.
• The ridge on the labial surface is called the labial ridge, which is curved and extends from the cusp tip to the cervical line.

Mesial outline:

• The mesial outline may be convex or slightly concave from the cervical Line to the mesial contact area.
• The mesial contact area is at the junction of the middle and the incisal Third.

Distal outline:

• The distal outline is concave from the cervical line to the distal contact Area.
• The distal contact area is at the middle of the middle third.

Cusp tip:

• The cusp tip is formed by the union of the mesial and distal cusp ridges (slopes) at a point.
• The distal slope is longer than the mesial slope. The slope may exhibit Concavities before wear has taken place.
• The junction between the mesial slope and the mesial outline is sharp And the junction between the distal slope and the distal outline is more Rounded.

Cervical line:

• It is convex with the convexity towards the root.

Features of the root:

• The root is slender compared to the bulk of the crown; conical in shape with a blunt and pointed apex.
• The tip of the root may be curved in a distal direction in the apical third in most of the cases.

Lingual aspect:

Features of the crown:

Shape and surface:

• The crown tapers in a lingual direction and there is a tendency towards Concavities.

Cingulum:

• The cingulum is large, prominent and pointed and located in the Cervical third of the crown and centred mesiodistally; it might Resemble a small cusp.

Lingual fossa and marginal ridges:

• The lingual fossa in the canine is more pronounced than in the anterior teeth.
• The mesial and distal marginal ridges border the lingual fossae And are prominent in nature.
• A well-developed lingual ridge that runs in a cervicoincisal direction From the cusp tip to the cingulum divides the lingual fossa into the Mesial and distal lingual fossae.
• The cingulum, marginal ridges and the lingual ridge are confluent with The absence/lack of evidence of developmental grooves.
• Developmental grooves may not be seen.

Features of the root:

• The root is thinner than the labial aspect and most of the mesial and the distal surface of the root is seen.
• Developmental depressions may be seen extending along the root length.

Mesial aspect:

Features of the crown:

Shape and surface:

• Crown is triangular or wedge shaped with the apex of the triangle being the tip of the cusp.
• The labiolingual measurement is greater than the rest of the anterior Teeth.
• The mesial surface exhibits convexities at all points on the mesial aspect except a small point between the contact area and the cervical Line which is slightly concave and flat.

Labial and lingual outline:

• The labial outline is convex in the cervical third and then straight to the cusp tip.
• The labial and lingual crest of curvatures correspond to that of the Maxillary central and lateral incisors but might be more incisal due to The well-developed middle labial and lingual lobes.
• The labial crest of curvature is in the cervical third.
• The lingual outline
  • Convex in the cervical third due to the cingulum, straightens In the middle third and becomes convex in the incisal third
• The lingual crest of curvature is in at the cingulum which is in the Cervical third.

Cusp tip:

• The cusp tip is labial to the line bisecting the tooth labiolingually.

Cervical line:

• The cervical line is curved towards the crown exhibiting greater Curvature on the mesial side.
• It curves by approximately 2.5 mm from the cementoenamel junction Towards the cusp tip

Features of the root:

• The root is conical with a tapered apex.
• A shallow developmental depression may be present along a part of the root Length. The root might be labially curved in the apical one-third.

Distal aspect:

The distal aspect is similar to the mesial aspect except the following differences:

• Lesser curvature of the cervical line
• Heavier and irregular distal marginal ridge
• More concave surface
• More pronounced developmental grooves

Incisal aspect:

• The labiolingual dimension is more than the mesiodistal dimension.
• The cusp tip is labial to the centre of the crown labiolingually and is mesial to the centre mesiodistally.
• When bisected labolingually the mesial portion of the crown would have greater bulk labiolingually and the distal portion would seem to be stretched to make contact with the first premolar.
• The labial ridge is more prominent labially from the incisal aspect and is most convex at the cervical one third of the crown and becomes flatter in the middle and incisal third.
• The arc of the lingual outline is shorter than that of the labial outline due to the cingulum and the lingual convergence of the tooth.
• The features that can help in identificaton of the maxillarym canine are given in boxx.

Features to identify the maxillary canine:

• Labial ridge on the crown
• Prominent cingulum occupying the cervical third of the lingual surface
• Two lingual fosaa with a lingual ridge between them

Differentiation Between Right And The Left Maxillary Canine

• Distal slope is longer than the mesial slope.
• The root may exhibit a distal tilt.

Development And Landmarks Crown And Root Of The Maxillary Canine

Variation And Developmental Anomalies

• Canines are the second most common impacted teeth after the third molars.

The Permanent Maxillary Canine Synopsis

Labial aspect:

Crown:

• The surface of the crown is smooth and convex with a well-developed middle Lobe.
• The ridge on the labial surface is called the labial ridge.
• Mesial outline is convex or slightly concave. The mesial contact area is at the junction of the middle and the incisal third.
• Distal outline is concave. The distal contact area is at the middle of the middle third of the crown.
• The cusp tip is formed by the union of the mesial and distal slopes with the distal slope being longer than the mesial slope.
• Cervical line is convex with the convexity towards the root.

Root:

• It is conical in shape with a blunt and pointed apex.

Lingual aspect:

Crown:

• The crown tapers in a lingual direction.
• Cingulum is in the cervical third of the crown and centred mesiodistally
• The lingual fossa in the canine is more pronounced than in the anterior teeth.
• A well-developed lingual ridge that runs in a cervicoincisal direction from the cusp tip to the cingulum is present.

Root:

• It is narrower than the labial aspect.

Mesial aspect:

Crown:

• Crown is triangular or wedge shaped with the apex being the tip of the cusp.
• The labiolingual measurement is greater than the rest of the anterior teeth.
• The labial outline is convex in the cervical third; the labial crest of curvature is located in the cervical third.
• The lingual outline is convex in the cervical third due to the cingulum.
• A line bisecting the cusp is labial to a line bisecting the root.
• Cervical line is curved towards the crown exhibiting greater curvature on the mesial side.

Root:

• It is conical with a tapered apex.
• A shallow developmental depression may be present along a part of the root Length.

Distal aspect:

• The distal aspect is similar to the mesial aspect except the following differences:
• Lesser curvature of the cervical line
• Heavier and irregular distal marginal ridge
• More concave surface
• More pronounced developmental grooves

Incisal aspect:

• The labiolingual dimension is more than the mesiodistal dimension.
• The tip of the cusp is labial to the centre of the crown labiolingually and is mesial to the centre mesiodistally.
• The arc of the lingual outline is shorter than that of the labial outline due to the cingulum the lingual convergence of the tooth.