Figure 2.

Arch width and length (mm). ICD, inter-canine distance; distance between the cusp tips of right and left permanent canines; IPD, inter-premolar distance; distance between the tip of the buccal cusp of the right and left first premolars; IMD, inter-molar distance; distance between the tip of the mesiobuccal cusp of the right and left first permanent molars; AL, arch length; the distance between the incisal edge of the most prominent central incisor to the frontal/coronal plane passing through the most posterior aspect of the first permanent molars. In case of abrasion of a cusp, the centre of the abrasion facet was used instead of the centre of the cusp.