Central Incisors


Maxillary Centrals

Mandibular Centrals


Mesial: incisal 3rd, near edge

Distal: near junct. Of incisal & mid 3rd.

Both well within the incisal 3rd & at about same height.


Longest & widest of incisors. Longer than wide.

5/8th the width of max. Very narrow. Symmetrical

Incisal Angles

Mesioincisal: about 90 degrees.

Distoincisal: more rounded & obtuse.

Distoincisal may be slightly rounded. However both basically 90 degrees.

Incisal edge

Slopes cervically distally



Root slightly longer than crown.

Root longer than crown, more so than max.

Root shape

As thick M.D. as F.L. Thick at cerv. 3rd. *not great anchor root due to conical/shortness.

*Wider F.L. than M.D by 2.0 mm.

Lingual fossae

Less developeed than laterals. Can be shallow to deep. Deep w/ prominent marginal ridges are called shovel-shaped.

Barely discernible. Lingual surface has concavity instead.


Well developed. Centered toward distal. Sits distal to the long axis.

Small, centered & smoothe.

Marginal ridges

Prominent. Mesial longer than distal due to cingulum placement.

Barely discernible


May possess where marginal ridges meet. Fossae contain pits. If pits than fossae are present.


Accessory lingual ridges

May possess 1 to 4


Root depression

On mesial ONLY, runs longitudinally at junct of midddle & lingual 3rd. Mesial root is flattened.

Roots flat. Both mesial and distal in middle 3rd.

Incisal Edge

1.5 to 2.0 mm. Slightly labial to long axis of root. *Distoincisal edge may be just lingual due to twisting.

2.0 mm thick & runs straight. Lingual to the long axis of the root.


More curvature on mesial than distal.

Mesial curve (2.0 mm) more incisally than distal (1.6 mm). Only way to determine left from right.

Height of contour

Labial: cerv. 3rd just incisal to cervical line.

Lingual: cervical 3rd.

Labial: cervical 3rd. Note, labial surface can appear flat.

Lingual: cervical 3rd.

Crown width

Wider M.D. than F.L.

Wider F.L. than M.D.

Crown outline

Triangular, curved labially.

Labial is slightly convex.

Labial depressions


Shallow, less pronounced

Root Curvature


Root tip may bend distally