MANDIBULAR CANINE

2. MANDIBULAR CANINE (8) 33 43 Prof. A. El-Sahn

3. CHRONOLOGY • Initial calcification : 4 – 5 month after birth • Completion of crown: 6 – 7 years • Eruption : 9 – 10 years • Completion of root : 12 – 14 years Prof. A. El-Sahn

4. 13 43 • The mandibular canine is the third tooth from the midline of the mandible. • It closely resembles the upper canine. Prof. A. El-Sahn

5. +0.4 mm. -0.8 mm. • Its features are less well developed than those of upper canine. • Its crown appears long and narrow compared with that of upper canine. • It is actually 0.4 mm. longer and 0.8 mm. narrower. Prof. A. El-Sahn

6. Labial aspect The crown The mesial outline: • Is nearly straight from the cervical line to the mesial contact area, then continues to the cusp slope. • It is nearly in line with the mesial side of the root and does not project or bulge beyond the root outline. M Prof. A. El-Sahn

7. Labial aspect The distal outline: Is slightly concave in the cervical third, then, it becomes convex incisally. It projects beyond the root outline. The distal outline is shorter than the mesial outline. From this aspect the crown appears to be tilted or bent distally due to the difference in mesial and distal outlines. D Prof. A. El-Sahn

8. Labial aspect The crown Incisal outline: The cusp tip is usually on the root axis line. Its slopes form a more obtuse angle than those of upper canine. The cusp is less pointed than that of upper canine. Prof. A. El-Sahn

9. Incisaloutline : (Cont.) • The mesial slope of the cusp is shorter than the distal slope, more so than on maxillary canine. • The mesial cusp slope is also in a more nearly horizontal plane compared to the longer distal cusp slope, which slopes more severely in an apical direction. M M Prof. A. El-Sahn

10. Labial aspect Contact areas: MesialIn the incisal third just below the mesioincisal angle. Distal At the junction of the middle and incisal thirds, more cervically located than the mesial contact area. Prof. A. El-Sahn

11. Labial aspect Cervical line: It has a semicircular curvature root ward. Morphology of the labial surface • The labial surface is smooth and convex. • It often shows a labial ridge, which is not as prominent as on the upper canine. Prof. A. El-Sahn

12. Shallow vertical depressions may be present on either side of the labial ridge in the incisalthird. • The incisal third of the crown is slightly flattened mesial and distal to the labial ridges. Morphology of the labial surface cont. Prof. A. El-Sahn

13. The root • The root is shorter than that of the upper canine by 0.6 mm to 2 mm. • Its apical end is more sharply pointed. • Its apical end is more often straight than curving toward mesial or distal sides. • The root is convex on the labial surface. -0.6 mm -2 mm. Prof. A. El-Sahn

14. Lingual aspect The crown The crown taper toward the lingual surface. The lingual surface of the crown resembles those of the lower incisors in being smooth, However; A faint lingual ridge is running from the cusp tip to the cingulum. Prof. A. El-Sahn

15. Lingual aspect The crown cont. • The marginal ridges are not prominent. • The mesial marginal ridge is longer and straighter than the shorter, more elevated and curved distal marginal ridge. • The cingulumis poorly developed Prof. A. El-Sahn

16. The Root • The lingual portion of the root is narrower than that of the upper canine. • The lingual surface of the root is convex. Prof. A. El-Sahn

17. Mesial aspect The Crown • The mesial surface of the crown is wedge-shaped. • The crown mesially is longer than of upper canine. • The crown is narrower labiolingually than the upper canine (by 0.4 mm). Prof. A. El-Sahn

18. Mesial aspect • The labial outline has less curvature than that of upper canine with very little crest of curvature directly above the cervical line. • The lingual outline is similar to that of the upper canine. The cingulum is not prominent. • Incisally: the incisal portion of the crown is thinner labiolingually. Prof. A. El-Sahn

19. Mesial aspect • The cusp appears more pointed. • The tip of the cusp is most often located slightly lingual to the root axis line, but it may be centered over it. Cervical line: Curves more incisally than does the cervical line on upper canine. Prof. A. El-Sahn

20. The Root • The root surface is similar to that of the upper canine from the mesial aspect except: • The root tip is more pointed than that of upper canine. • The developmental depression mesially is more pronounced than that on upper canine. Prof. A. El-Sahn

21. Distal aspect • The general shape from the distal aspect is similar to the shape from the mesial aspect. • The distoincisal angle is slightly more lingual in position than the cusp tip because of the distolingualtwist of the crown (similar to the lower lateral incisors). • The cervical line curvature is less on the distal surface than on the mesial surface. Prof. A. El-Sahn

22. The Root D D The vertical developmental depression on the distal side of the root is often deeper than the depression on the mesial side. Prof. A. El-Sahn

23. Incisal aspect • The outline of lower canine from the incisal aspect is often similar to that of upper canine. • The labiolingual dimension of the crown is longer than the mesiodistal dimension similar to upper canine. • The cusp tip is more likely to be inclined lingually. Prof. A. El-Sahn

24. Labially, the mesiolabial outline is more convex while the distolabial outline is flat or concave Incisal aspect The distal cusp slope is directed slightly lingually from the cusp tip, which places the distoincisal angle in a lingual position to the cusp tip. M D Prof. A. El-Sahn

25. This lingual placement of the distoincisal angle gives the incisal part of the crown a distolingual twist like lower lateral incisor. This twist matches closely the curvature of the dental arch. The crown tapers lingually and the cingulum is represented by a curved line. Prof. A. El-Sahn

27. Thank you Any Question ?