Untitled Quiz

Study Notes

The first two teeth from the midline, along with canines, are the anterior teeth of each quadrant.
The central incisor (CI) is closest to the midline, and the lateral incisor (LI) is the second tooth.
The maxillary CI crown is larger than the LI crown.
The mandibular LI crown and root are slightly larger than the CI.
Incisors are involved in three major functions: mastication, esthetics, and phonetics.
Mastication involves biting, incising, and shearing to break down food.
Esthetics include the size, shape, color, and placement of incisors that contribute to appearance and support facial features.
Phonetics include the use of incisors to make certain sounds.

The incisal edge is flattened, unlike the single cusp of canines or the multi-cusped occlusal surfaces of posterior teeth.
Mamellons are rounded enamel extensions on the incisal ridge of newly erupted incisors, usually three in number.
- They wear away after eruption and are usually not visible in adults.
Marginal ridges on the incisors are mesial and distal terminations of the lingual surface.
- They are parallel to the long axis.
- In posterior teeth, marginal ridges are on the occlusal surface and perpendicular to the long axis.
The lingual surface of an incisor has a lingual fossa which is a concavity and a cingulum which is a convex structure found in the cervical region.

General Characteristics:
- Positioned adjacent to the midline in the upper arch.
- Trapezoidal in shape, widest mesiodistally when viewed labially/lingually.
Development:
- Initiation of calcification: 3-4 months
- Completion of enamel: 4-5 years
- Eruption: 7-8 years
- Completion of root: 10 years

General: Convex from mesiodistally and incisogingivally.
- Convexity is most prominent in the cervical third.
Mesially: Convex but can be almost straight.
- Crest of curvature is near the contact area in the incisal third.
Distally: Convex with a rounded disto-incisal angle.
- The contact area is located very near the junction of the incisal middle third.
Incisally: Can exhibit mamellons.
- Has a straight outline nearly perpendicular to the long axis.
Cervically: Narrower mesiodistally at the cervical margin.

Depressions: Two straight, shallow depressions extending from the incisal edge toward the gingival, fading out in the middle third.
- These represent the division of the three labial lobes.
Imbrication lines: Faint curved lines parallel to the CEJ in the cervical third of the surface.
- Not always present.

General: Roughly trapezoidal, narrower mesiodistally.
- The mesial and distal surfaces slightly converge towards the lingual.
Fossa: Concavity in the incisal half to two-thirds.
Cingulum: Convex structure found in the cervical portion.
Mesial and Distal Outlines: Similar to labial counterparts with a slightly greater convergence toward the gingival.
Incisal Margin: Similar to the labial aspect.
Cervical Margin: Greater depth of curvature apically than the labial, asymmetrical.

Shallow concavity in the incisal half to two-thirds of the crown, encompassing the largest area of the lingual surface.
Bounded by four concave areas: mesial and distal marginal ridges, incisal edge, and cingulum.
Often smooth but can be poorly defined, forming a "W" shaped pattern.