Sales Training 2014 - Dentistry

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Tooth Morphology

Box 14.3 Chronology of Mandibular Canines

VARIATIONS

1. First evidence of calcification: 4 months 2. Enamel completion: 7 years 3. Eruption: 9–10 years 4. Root completion: 13 years

1. Sexual dimorphism: Maxillary canines exhibit sexual dimorphism (the systematic difference in form between individuals of different sex). 2. Bushman canine: It is an extra ridge on the me- sial slope of canine, commonly seen in blacks. 3. Tuberculum dentale: It refers to tubercles near the cingulum. 4. Distal accessory ridge: It is an extra ridge on the distal marginal ridge.

Box 14.4 Dimensions of Mandibular Canines

1. Length of the crown: 11 mm 2. Length of the root: 16 mm 3. Mesiodistal width of the crown: 7 mm 4. Mesiodistal width of the crown at cervix: 5.5 mm 5. Labiolingual width of the crown: 7.5 mm 6. Labiolingual width of the crown at cervix: 7.0 mm 7. Depth of curvature at the mesial aspect: 2.5 mm 8. Depth of curvature at the distal aspect: 1 mm

CLINICAL CONSIDERATIONS: MAXILLARY CANINES

SECTION II

1. The maxillary canines support the lip and the facial muscles. They form the cornerstone of the dental arches. Restorations involving canines should be done keeping this in mind because they have a significant impact on the aesthetics. 2. Maxillary canines are less likely to be affected by dental caries and periodontal problems as their morphology permits self-cleansing activity and increased anchorage. 3. Maxillary canines are impacted frequently due to reduced arch space. Surgical exposure and further orthodontic treatment is required to align them properly. 4. They play a very important role in phonetics (speech). 5. During lateral excursions or movements of the mandible, the upper and lower canines come in contact and prevent the posterior teeth from contacting. This canine guidance is considered the most physiologic of all occlusal relation- ships because it protects the posterior teeth from wear.

LABIAL ASPECT (FIG. 14.10) 1. Shape of the crown: The crown of the mandib- ular canine is trapezoidal.

Short mesial cusp ridge

Longer distal cusp ridge

Cervical line—semicircular curvature towards apex

(a)

Mesial outline is nearly straight

MANDIBULAR CANINE

The mandibular canines are similar to maxillary ca- nines but narrower mesiodistally and labiolingually. The crown height of mandibular canine is slightly longer than that of the maxillary canine. The chronology and dimensions of mandibular canines are stated in Boxes 14.3 and 14.4.

(b)

Figure 14.10 Labial aspect of the mandibular canine.

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