Comparison of tooth and arch dimensions in dental crowding and spacing

Abstract

Introduction: Any disproportion between tooth and arch dimensions predisposes to dental crowding and spacing, which are the most common forms of malocclusion. Hence, the objective of this study is to compare these elements between normal, crowded and spaced dental arches.

Material and Methods: A sample of 90 dental casts was collected and space analysis was performed by subtracting the sum of mesio-distal (MD) dimensions of all teeth (except the permanent molars) from the arch length. On the basis of this space analysis, the sample was divided into three groups, namely normal, crowded and spaced arches. ANOVA and Bonferroni post-hoc were performed for the comparison between the groups. A level of significance (p ≤ 0.05) was used for the statistical tests.

Results: There was a statistically significant difference in the MD dimensions of upper canines, upper first molars and lower incisors between crowded and normal arches (p<0.05), and upper incisors, lower canines and lower premolars between spaced and normal arches (p<0.05). A statistically significant difference was also found in the bucco-lingual (BL) dimensions of upper lateral incisors, upper right premolars, lower premolars and lower first molars between spaced and normal arches (p<0.05); in the arch perimeters between crowded and normal arches, as well as in the upper arch perimeters, lower inter-canine (IC) widths and lower inter-premolar (IP) widths between spaced and normal arches (p<0.05).

Conclusions: The normal dental arches differ from crowded and spaced dental arches in tooth and arch dimensions.