Arch Traits

Arch traits are characteristics that differentiate the maxillary and mandibular teeth in the same class.

The incisal ridge in maxillary incisors is centred labiolingually while mandibular incisors have the incisal ridge lingual to a line bisecting the root.

In the maxillary arch, the permanent maxillary central incisor is larger than the permanent maxillary lateral incisor while the opposite is true in the mandibular arch.

The permanent maxillary incisors have a deeper, more well-defined lingual fossa compared to the flatter, less developed lingual fossa of the mandibular incisors.

The permanent maxillary central and lateral incisors are wider mesiodistally than their mandibular counterparts.

The cingula of the permanent maxillary incisors are more prominent compared to the mandibular incisors.

A cross-section of the root of the permanent maxillary incisors is conical or triangular while the root of the mandibular incisors is hour-glass shaped (wide labiolingually with mesial and distal root depressions).

The crowns of permanent maxillary incisors are wider mesiodistally than labiolingually while the opposite is true of the mandibular incisors.