MAXILLARY CANINE

Number and Position: Four in total; each arch contains a pair located third from the midline on both the maxillary and mandibular arches.
Development and Replacement: Maxillary canines replace the deciduous canines and function alongside the incisors and premolars.
Naming and Tooth Numbering: Often called cuspids, they serve as cornerstones in the dental arch due to their position. The FDI numbering system lists them as 13, 23 (maxillary) and 33, 43 (mandibular).

Location: Positioned distal to lateral incisors and mesial to first premolars.
Nickname: Known as “cornerstones” of the arches for their stabilizing role.
Dimensions: Longest teeth in the permanent dentition, featuring large, pointed cusps that have distinct mesial and distal cusp ridges.

Mastication: Specializes in tearing and shearing food, complementing the functions of other teeth.
Lip Support: Provides structural support to the lips.
Auxiliary Role in Chewing: Assists incisors and premolars in breaking down food.
Guidance for Jaw Movement: Guides other teeth during occlusion by directing jaw movements, helping to avoid excessive wear and fractures on other teeth.

Crown Shape: Mesiodistally narrower than the central incisor, giving it a more tapered, pentagonal shape.
Cusp and Slopes: The incisal outline features a distinct pointed cusp tip. The mesial slope of the cusp is shorter than the distal slope.
Cervical Line: The cervical line is convex toward the root.
Contact Points:
- Mesial Contact: Located near the junction of the incisal and middle thirds, closer to the cusp tip.
- Distal Contact: Situated in the middle of the middle third, positioned more cervically than the mesial contact.
Elevations:
- Cusp: Centrally aligned with the root axis.
- Labial Ridge: A prominent vertical ridge that runs down the middle of the labial surface.
Depressions:
- Two shallow longitudinal grooves flank the labial ridge, creating a more contoured labial surface.

The primary cusp has two ridges:
- Mesial Cusp Ridge: Shorter than the distal ridge.
- Distal Cusp Ridge: Longer and slightly more sloped.

Shape and Size: The root is a single, long, slender, conical structure with a pointed apex.
Surface: Smooth and convex on the labial side, typically curving distally in the apical third.
Curvature: In most cases, the root's apical portion curves slightly in a distal direction.

Narrower Crown: The crown narrows towards the lingual side.
Elevations:
- Cingulum: Large and sometimes resembles a cusp in the center of the lingual surface.
- Lingual Ridge: A prominent vertical ridge that extends from the cusp tip down to the cingulum. This ridge is unique to the canines.
- Marginal Ridges: The mesial marginal ridge is longer than the distal due to the shorter mesial cusp slope and the location of the mesial contact area.
Depressions:
- Lingual Fossae: Two shallow fossae flank the lingual ridge on the mesial and distal sides, adding texture and character to the lingual surface.

Shape: The crown has a wedge-shaped (triangular) outline.
Cervical Line: Curves toward the cusp, showing a less pronounced convexity compared to the incisors.
Cusp Tip Position: Slightly labial to the root's axis.
Root Characteristics:
- Form: Conical with a tapered or blunt apex that may curve slightly labially.
- Surfaces: The mesial surface of the root is broad with a shallow longitudinal depression that runs the length, adding stability.

Crown Shape: Similar to the mesial view but with a few differences:
- The cervical line has a reduced curvature toward the cusp.
- The distal surface is slightly concave below the contact area.
Root: The distal root depression is more pronounced than on the mesial surface, a feature helpful in identifying the tooth's orientation.

Dimensions: The labiolingual dimension is slightly greater than the mesiodistal dimension.
Contour: The labial surface is more convex than that of the incisors, enhancing the tooth's strength and stability in the arch.