Ch 13 Canines
Canines
Overview of Canines
Description of canines:
Four permanent canines: two maxillary and two mandibular.
Location: located at the corners of the mouth, acting as anchors due to long roots and canine eminence (special bone projection).
Function:
Act as holding and tearing tools.
Assist incisors and premolars.
Self-cleaning qualities
Shape: "V" shape at the corners of the mouth dissipates pressure on surrounding teeth (incisors and premolars).
Stability: canines considered the most stable teeth due to:
Long, thick roots.
Smooth, pointed shape.
Maxillary Canines
Calcification times:
Evidence of calcification: 4 months.
Enamel completion: 6 to 7 years.
Eruption: 11 to 12 years.
Root completion: 13 to 15 years.
General Structure
Similar to incisors, consisting of four developmental lobes:
Three facial lobes, one lingual lobe.
Middle facial lobe extends incisally more than others, forming a single cusp.
Cusp tip forms at the junction of four ridges (two facial, two lingual).
Lingual lobe is larger than that of incisors, resulting in a wider labiolingual measurement.
Cingulum:
Well-developed, larger and bulkier than any other anterior teeth.
Labial Aspect
Crown and root are narrower mesiodistally compared to maxillary central incisor.
Crown length:
Longer than most anterior teeth (except for maxillary central incisor, mandibular canine).
Mesial and distal contours:
Mesial: straighter outline.
Distal: rounded appearance.
Contact Areas:
Mesial contact area at the junction of the middle and incisal thirds of the crown.
Distal contact area at the center of the middle third.
Distal contact area is positioned more cervically than the mesial contact area.
Cervical line crests slightly mesial to the center of the crown.
Root: slender, conical with a blunt apex.
Apical curvature often towards the distal side.
Lingual Aspect
Root tapers toward the lingual.
Cervical line: even curvature, centered over the middle of the tooth.
Prominent structures:
Well-developed cingulum and lingual ridge.
Lingual ridge creates mesial and distal lingual fossae, bordered by marginal ridges.
Cross-section of root: triangular.
Mesial Aspect
Wedge-shaped outline indicative of function:
Larger labiolingual bulk compared to any anterior tooth.
Greatest measurement at cervical third.
Cervical line curves toward cusp tip an average of 2.5 mm.
Root: broad labiolingually, with potential for apical curvature.
Developmental depression present on mesial root, aiding in anchorage.
Distal Aspect
Similar form as mesial aspect.
Outlines and curvature:
Distal marginal ridge is more developed than mesial ridge.
Distal surface displays more concavity than mesial surface.
Incisal Aspect
Incisal view shows:
Wide mesiodistally and thickest labiolingually among anterior teeth.
Cusp tip is labial to center and mesial to the mesiodistal center.
Distal aspect of crown appears thinner than mesial aspect.
Root Structure
Longest root compared to any tooth, tapering from labial to lingual.
Cross-sectional view shows tapered shape.
Apical portion may point distally.
Pulp Cavity
Large pulp chamber with a single pulp canal and one pulp horn extending toward the cusp tip.
Important Data for Maxillary Canines
Identifying Characteristics:
Universal code: 6 (right), 11 (left).
International code: 13 (right), 23 (left).
Palmer notation: with one root and one cusp.
Proximal contact areas:
Mesial: junction of incisal and middle thirds.
Distal: middle third.
Height of Contour:
Facial: cervical third, 0.5 mm.
Lingual: cervical third, 0.5 mm.
Mandibular Canines
Calcification times:
Evidence of calcification: 4 months.
Enamel completion: 7 years.
Eruption: 9 to 10 years.
Root completion: 13 years.
General Structure
Resemble maxillary canines in shape and structure but differ in:
Crown narrower mesiodistally (about 0.5 mm).
Longer crown length than maxillary canine.
Root may be equal in length but usually shorter than that of a maxillary canine.
Smaller labiolingual measurements compared to maxillary canines.
Smoother lingual surface, less developed cingulum and marginal ridges.
Less pronounced cusp tip development with thinner labiolingual cusp ridges.
Cusp tip may be more lingually centered compared to maxillary canine.
Potential presence of bifurcated roots.
Distal contact area located more incisal than that of the maxillary canine.
Labial Aspect
Straighter mesial outline than maxillary counterpart.
Distal outline resembles the maxillary canine's distal outline but is less convex.
Distal contact area more incisal and somewhat cervical to the junction of the incisal and middle thirds.
Mesial contact area positioned nearer the mesioincisal point.
Lingual Aspect
Crown is flatter compared to maxillary canines.
Lingual features less prominent, with a larger cingulum than other mandibular anterior teeth but less developed than maxillary canines.
No lingual pits present.
Mesial Aspect
Similar in wedge shape to maxillary canines but with:
Less developed cingulum and thinner marginal ridges.
Lingually inclined cusp tip compared to maxillary canine.
Distal Aspect
Similar appearance to the mesial view.
Incisal Aspect
Distal incisal ridge slants more lingually compared to the mesial ridge.
Cusp tip is positioned more lingually.
Root Structure
Root: longest of the mandibular teeth, second only to maxillary canine roots, wide labiolingually and narrow mesiodistally.
Bifurcated roots possible in apical third.
Pulp Cavity
Similar to maxillary canine structure, but may contain two canals in bifurcated roots (labial and lingual) with separate apical foramina.
Important Data for Mandibular Canines
Identifying Characteristics:
Universal code: 27 (right), 22 (left).
International code: 43 (right), 33 (left).
Palmer notation indicates one or two roots.
Proximal contact areas:
Mesial: incisal third.
Distal: just cervical to the junction of incisal and middle thirds.
Height of Contour:
Facial: cervical third, less than 0.5 mm.
Lingual: cervical third, less than 0.5 mm.