Three-dimensional digital evaluation of tooth symmetry and volume in patients with missing and peg-shaped maxillary lateral incisors

Abstract

This study aimed to evaluate the 3-dimensional tooth crown symmetry and the crown volumes of maxillary and mandibular teeth in patients with unilateral or bilateral missing or peg-shaped maxillary lateral incisors. Six groups were established for the possible clinical variations in patients with unilateral missing or peg-shaped maxillary lateral incisors, bilateral presence of these tooth anomalies, and a control group (CG) with normal lateral incisors. The study was conducted on digital dental models of 132 patients. The morphologic symmetry of the antimere teeth was investigated using 3-dimensional deviation analysis. Volumes of contralateral teeth were compared within and among groups for the maxilla and mandible. Furthermore, volumes of teeth were compared in missing and peg-shaped quadrants and quadrants of CG. Intergroup differences were tested using one-way analysis of variance and Kruskal-Wallis tests, whereas paired t and Wilcoxon tests were used for parametric and nonparametric variables, respectively, for intragroup comparisons. Significant deviations in symmetry of antimere teeth were not detected (P>0.05). The volumes of mandibular central and lateral incisors in missing or peg-shaped lateral incisor groups were smaller than in the CG (P<0.05). Per quadrant analysis, volumes of the maxillary central incisor and mandibular central incisors, canines, and first molars in quadrants with missing or peg-shaped lateral incisors were smaller than in the control quadrants (P<0.05). Neither unilateral nor bilateral presence of missing or peg-shaped maxillary lateral incisors affected the morphologic symmetry of antimere teeth but did affect tooth volume, especially in the mandibular arch.