Comparison of three-dimensional soft-tissue evaluations between skeletal and pseudo-class III malocclusions

Abstract

The aim of our study was to compare soft tissue measurements with 3D imaging methods in individuals with untreated skeletal and pseudo-Class III malocclusions. The study sample consisted of 75 patients (38 males, 37 females, mean age 12.41 ± 2.35 years) with pseudo- and true skeletal Class III malocclusions and skeletal Class I malocclusions. Soft tissue evaluations of all patients were performed using 3D stereophotogrammetric facial images. In our study, 26 landmarks, 17 linear measurements, 13 angular measurements, and 5 volume measurements were made using the 3dMD Vultus software. The signifcance was determined to be p < 0.05 in ANOVA, Tukey tests. No signifcant diferences were found among the groups in terms of demographic data (p> 0.05). The skeletal Class I control group had a signifcantly more extended upper lip and vermillion length as compared to the Class III groups. The soft tissue convexity angle and upper nasal angle were found to be wider in the Class III malocclusion group compared to those in the Class I control group. While the pseudo-Class III group had a signifcantly lower midface volume, chin volume was signifcantly higher in the skeletal class group. Upper lip volume was signifcantly higher in the Class I group. Using 3dMD for guiding clinicians in the diferential soft and hard tissue diagnosis of pseudo-Class III malocclusions, diferences were revealed in Class I patients in the middle part of the face. In the diferential diagnosis of true Class III malocclusions, chin volume was found to be diferent from that of Class I patients.