Mandibular Canines PDF

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Summary

Chronology and morphology of the mandibular canine...

Description

Maxillary and mandibular canines: Functions: - Holding/tearing tools, assist both incisors and premolars - Their shape allows for dissipation of pressure at the corner of the mouth support oral tissues - Provide ‘guidance’ for normal occlusion, especially when the mandible is moved sideways - Ensures normal facial expression Features: 1. Robust tooth forming the ‘corner’ of each dental quadrant 2. Incisal edge is sloped to a sharp cusp tip that lies more mesially than distally 3. Single root, longest of all teeth, bony covering forms the canine eminence of the alveolar process, especially prominent in the maxilla - thus stable 4. Root apex sometimes curves distally slightly 5. Upper and lower canines have a cingulum, the upper is joined to the cusp tip by a palatal ridge 6. The middle labial lobes have been highly developed incisally into strong, well-formed cusps. 7. Crowns and roots are markedly convex on most surfaces. 8. Single pointed cusps with great labiolingual thickness Mandibular canine Evidence of calcification: 4 -5 months Enamel formation: 6-7 years Eruption: 9 - 10 years Root completed: 12-14 years Identifying features: 1. Distal profile of crown more rounded than mesial 2. Crown narrower mesiodistally than maxillary canine so that crown appears larger in proportion. 3. Only the mandibular canine is capable of bifurcated root, a not uncommon variation 4. Cusp not as well developed and cusp ridges thinner labio lingually and sometimes cusp tip lies lingually to the root

Aspect

Features

Labial

1. Crown is narrower than maxillary canine. 2. Crown appears longer because of its narrowness than maxillary crown. 3. Mesial outline is almost straight. 4. Mesial slope of cusp is shorter than distal slope. 5. Crown appears to be tilted distally because there is more of crown distal to long axis of root than mesial to it. 6. Mesial and distal contact more incisal

Lingual

1. Lingual surface is flatter/smoother in comparison to maxillary canine. 2. Cingulum is not very much prominent and tapers lingually 3. Mesial marginal ridge is longer than the distal marginal ridge and less bulk to MR 4. Resembles other mandibular anteriors but larger cingulum and lingual ridge

Drawing (right)

Proximal

Mesial 1. Wedge shaped with cusp tip almost centered over the root. 2. Curvature of cervical line is more than on maxillary canine. 3. Due to less prominence of cingulum and less labiolingual thickness of crown, cusp appears more pointed with slender cusp ridge. Distal It is almost similar to mesial aspect except: 1. Crown is twisted distolingually, so distolingual angle is positioned slightly lingual than cusp tip. 2. Curvature of cervical line is less than on mesial side.

Incisal

1. Mesiodistal dimensions are lesser than labiolingual dimensions. 2. Cusp tip and mesial cusp ridge are lingually placed. 3. Tooth appears to have distolingual twist....