Maxillary Lateral Incisor Morphology and Chronology

A comprehensive vocabulary review of the maxillary lateral incisor covering developmental chronology, crown and root anatomy across all aspects, and common dental anomalies.

First evidence of calcification

The developmental stage of the maxillary lateral incisor that occurs at $1\,\text{yr}$.

Enamel completed (maxillary lateral incisor)

The developmental timeframe at which the crown's enamel completion is achieved, occurring at $4\text{--}5\,\text{yrs}$.

Eruption (maxillary lateral incisor)

The eruption time of the permanent maxillary lateral incisor into the oral cavity, which occurs at $8\text{--}9\,\text{yrs}$.

Root completed (maxillary lateral incisor)

The developmental milestone marking complete root apex formation, occurring at $11\,\text{yrs}$.

Geometric outline of the crown (labial aspect)

Trapezoidal, with the shortest of the uneven sides positioned cervically.

Mesial outline (labial aspect)

Slightly convex outline with a rounded mesioincisal angle and a contact area located at the junction between the middle and the incisal thirds.

Distal outline (labial aspect)

More convex outline with a more rounded distoincisal angle and a contact area positioned at the center of the middle third.

Labial cervical line

The cervical line on the labial aspect that curves with its convexity directed rootwise.

Labial surface

A smooth surface that is more convex than that of the maxillary central incisor.

Root apex curvature (maxillary lateral incisor)

A pointed root apex that curves sharply in a distal direction and is longer in proportion to the crown than that of the central incisor.

Lingual fossa (maxillary lateral incisor)

A more concave, $U$-shaped depression bounded by prominent mesial and distal marginal ridges, a cingulum, and an incisal ridge.

Mesial aspect incisal ridge bisector

An anatomical feature where a line drawn through the center of the root tends to bisect the incisal ridge of the crown, similar to the maxillary central incisor.

Labiolingual measurement (mesial aspect)

The labiolingual measurement of the crown and root, which is a millimeter or so less than that of the maxillary central incisor of the same mouth.

Mesial cervical line curvature

Curvature that is concave rootwise, with an actual extent of curvature less than that found on the central incisor due to the smaller crown size.

Distal cervical line curvature

The curvature of the cervical line on the distal aspect, which is usually a millimeter or so less in depth than on the mesial side.

Incisal aspect outline

Similar in shape to the maxillary central incisor except that it is more convex both labially and lingually.

Peg-shaped lateral incisor

A frequent dental anomaly where the maxillary lateral incisor develops with a diminutive, conical, or peg-shaped crown.

Congenitally-missing lateral incisor

A frequent anomaly marked by the complete developmental failure and absence of the maxillary lateral incisor in the dental arch.

Cingulum with tubercle

A frequent anatomical variation characterized by an accessory cusp or prominent projection arising from the cingulum on the lingual aspect.