Tooth Morphology Part 3: Canines – Structure, Symmetry, and Function

The canines are the cornerstone teeth of the dental arch, uniquely adapted for tearing food and guiding occlusal movement. In this post, we examine the morphology of maxillary and mandibular canines, their distinguishing features, and their crucial role in canine guidance during lateral excursion. All descriptions follow the FDI numbering system.

Maxillary and mandibular canines illustrated side-by-side with labial and lingual views — An anatomical comparison of upper and lower canines, highlighting symmetry and cusp structure

🔢 FDI Numbers for Canines

13, 23: Maxillary canines
33, 43: Mandibular canines

Key Morphological Features

Longest root: Maxillary canine (~17 mm), contributing to excellent anchorage and esthetics
Single pointed cusp: Designed for tearing and penetration of food
Labial prominence: More prominent in maxillary canines, creating a key facial contour
Cervical constriction: Stronger in mandibular canines, giving them a more slender appearance
Cusp tip position: Centered labiolingually in maxillary, inclined lingually in mandibular

⚖️ Maxillary vs Mandibular Canines

Feature	Maxillary Canines	Mandibular Canines
Root Length	~17 mm	~16 mm
Labial Ridge	More pronounced	Less prominent
Lingual Anatomy	More developed (cingulum and ridges)	Flatter
Cusp Tip Position	Centered	Lingually inclined
Mesial Outline	Convex	Straighter
Distal Contact	More cervical	Level or incisal

Canine Tooth Structure – Cross Section View — Canine Guidance in Lateral Excursion

🧠 Clinical Significance

Esthetics: Canines support the alar-facial curve and contribute to smile harmony
Occlusion: In canine-guided occlusion, they protect posterior teeth from lateral forces
Restorative relevance: Their long root and strategic location make them ideal abutments for prosthetics

🌟 Summary: Key Points to Remember

Canines are the longest and most stable teeth in the arch
Maxillary canines have greater bulk and prominence; mandibular are more slender
They serve as both esthetic and functional keystones in dental occlusion

From archived insight to open reflection – a living note of science and thought.

Next up: Part 4 – Premolars: between canines and molars in form and function.