Permanent Canines

Why are canines called the 'cornerstone' of the arch?

Long crowns and roots; most stable teeth (longest roots); maintain arch form

Canine eminence

Bony bulge over the long canine root (key term)

Do canines usually have developmental anomalies?

No — usually develop uniformly without anomalies

5 functions of canines

Tearing food, guiding occlusion (canine guidance), maintaining arch form, esthetic support, anchorage

Last succedaneous tooth to erupt

Maxillary canine (11–12 yr)

Max canine (#6, 11): calcification / eruption / root complete

4–5 months / 11–12 yr / 13–15 yr

Mand canine (#22, 27): calcification / eruption / root complete

4–5 months / 9–10 yr / 12–14 yr

Longest tooth overall (crown + root)

Maxillary canine

Longest root in the mouth

Maxillary canine

Longest crown in the permanent dentition

Mandibular canine

Maxillary canine crown length rank

3rd longest crown

Mandibular canine root length rank

2nd longest root

Widest anterior tooth faciolingually

Maxillary canine

Tooth with the widest pulp canal labiolingually

Maxillary canine

Maxillary canine: cusps and roots

Single cusp, one root

Canine facial geometric outline

Trapezoidal; crown is pseudo-pentagonal

Maxillary canine: most developed facial lobe

Mid-facial lobe → prominent facial ridge

Canine cusp slopes: which is longer?

Distal cusp slope is longer than mesial (both canines)

Maxillary canine: root (facial view)

Conical with a bluntly pointed apex

Maxillary canine: HOC mesial / distal

Mesial: junction of incisal and middle thirds. Distal: middle third

Facial and lingual HOC of all anterior teeth (incl. canines)

Cervical third

Canine mesial geometric outline

Wedge shaped

Maxillary canine: cusp tip relative to long axis

Facial (labial) to the long axis

Maxillary canine: root developmental depressions

Shallow on mesial; deeper on distal

Maxillary canine: lingual convexity

Crown and root converge lingually; more convex on distal than mesial

6 lingual features of canines

Mesial marginal ridge, distal marginal ridge, cingulum, lingual ridge, mesiolingual fossa, distolingual fossa

Maxillary canine cervical area

Thicker than mandibular canine ('muffin top')

Maxillary canine: incisal view

Very noticeable facial ridge; wider BL than MD; distal dip (concave); 4 ridges meet at cusp tip

Ridges that form the canine cusp tip

All 4 ridges (mesial and distal cusp ridges, facial ridge, lingual ridge)

Maxillary canine: root (pulp)

One root; may curve distally at apex; wider labiolingually than MD; ovoid cross-section with flattened M and D

Maxillary canine: canal and horns

1 canal, 1 pointed pulp horn; widest canal labiolingually of any tooth

Mandibular canine vs maxillary canine: general

Resembles maxillary but anatomy less prominent

Mandibular canine: facial view

Trapezoidal/pseudo-pentagonal; longest crown; mesial surface of crown and root in line

Mandibular canine: root (facial view)

Conical, pointed apex, usually curves mesially

Mandibular canine: HOC mesial / distal

Mesial: incisal third. Distal: middle third

Mandibular canine: mesial view

Wedge; deep root depression on mesial; proximal outline is a smooth continuous arc

Mandibular canine: lingual anatomy

Same 6 features as maxillary but less well developed

Mandibular canine: lingual view outline

Mesial outline straight; distal more convex

Mandibular canine: cusp tip relative to long axis

In line with or slightly lingual to the long axis

Mandibular canine: incisal view

Distal concavity like maxillary; FL dimension greater than MD

Mandibular canine: root

One root (may bifurcate); 2nd longest root; elliptical cross-section; concavities (mesial deeper); apex deviates mesially

Mandibular canine: canal

1 canal, bifurcates 25%; 1 pointed pulp horn; pulp widest BL in cervical third of crown

Only tooth whose apex tends to deviate mesially

Mandibular canine

Max vs mand canine: longest

Max: longest tooth and root (3rd longest crown). Mand: longest crown (2nd longest root)

Max vs mand canine: cusp tip position

Max: facial to long axis. Mand: in line or slightly lingual

Max vs mand canine: HOC mesial/distal

Max: junction incisal-middle / middle. Mand: incisal / middle

Max vs mand canine: cervical area

Max: thicker ('muffin top'). Mand: thinner

Max vs mand canine: deeper root depression

Max: distal. Mand: mesial

Max vs mand canine: apex direction

Max: may curve distally. Mand: deviates mesially

Max vs mand canine: lingual anatomy

Max: well defined. Mand: less well developed

Max vs mand canine: canals

Max: 1 canal (widest FL of any tooth). Mand: 1 canal, bifurcates 25%

Canine-guided occlusion

In the ideal adult dentition, during lateral excursions the posterior teeth disocclude and only the canine cusp tips touch

Group function

Multiple maxillary and mandibular teeth contact during lateral movements — indicates a worn dentition

What causes loss of canine guidance?

Moderate–severe bruxism wears the cusp tip into a flat incisal table → group function

IMAGE (max canine facial): yellow outline

Trapezoidal geometric outline

IMAGE (max canine facial): green outline

Pseudo-pentagonal crown shape

IMAGE (max canine facial): red diamond

Facial ridge (most developed mid-facial lobe)

IMAGE (max canine facial): blue arrow

Longest tooth in the mouth (crown + root)

IMAGE (max canine lingual): red oval

Cingulum

IMAGE (max canine lingual): green bars

Mesial and distal marginal ridges

IMAGE (max canine lingual): blue triangle

Lingual ridge

IMAGE (max canine lingual): purple triangles

Mesiolingual and distolingual fossae

IMAGE (max canine lingual): yellow dashed line on distal

Distal outline more convex than mesial

What are the canines called? Why?

Cornerstone of the arches; long crowns and roots, most stable

Five functions of canines?

Tearing, guiding occlusion, maintaining arch form, esthetic support, anchorage

Longest tooth overall? Longest crown?

Maxillary canine; mandibular canine

Which canine has the widest pulp canal FL of any tooth?

Maxillary

Cusp tip vs long axis: max and mand?

Facial; in line or slightly lingual

HOC mesial/distal: max vs mand?

Junction incisal-middle / middle; incisal / middle

Facial and lingual HOC of all anteriors?

Cervical third

Which cusp slope is longer?

Distal (both canines)

Name the 6 lingual features.

MMR, DMR, cingulum, lingual ridge, mesiolingual fossa, distolingual fossa

Root depression: which side is deeper in max? In mand?

Distal; mesial

Direction the apex tends to deviate: max, mand?

Distal (may); mesial

Mandibular canine canal bifurcation?

25%

What causes loss of canine guidance? Result?

Bruxism wear flattens cusp; group function