Date: June 2021.
Source: Orthodontics & Craniofacial Research,
Objective: To assess the soft tissue changes in orthodontic extraction and non-extraction patients on 3D stereophotogrammetric images.
Setting and sample: 23 extraction (22.2 ± 9.2 years) and 23 non-extraction (20.3 ± 11.1 years) consecutive patients were enrolled at the Sections of Orthodontics at Aarhus University and at University of Naples Federico II.
Materials and Methods: All patients had a first 3D image taken after bonding of brackets on the upper incisors (T0), and a second 3D image (T1) after space closure in the extraction group or at insertion of the first SS or TMA rectangular wire in the non-extraction group. The 3D images were captured with 3dMDface System and analysed with 3dMDvultus Software. After placing 19 landmarks, 15 measurements were obtained. Intragroup changes were analysed with paired t-test and intergroup changes with unpaired t-test (P < .05).
Results: Superimpositions of the 3D images at T0 and T1 visualized with colour-coded maps showed that soft tissue changes primarily happened in the perioral area in both groups. The Nasolabial angle increased significantly in the extraction group (3°± 4.1, P = .002), while it decreased in the non-extraction group (−1.5°± 5.5°, P = .002). There was a significant difference between the two groups (4.4°, P = .004).
Conclusions: 3D comparison of the soft tissues in the extraction and non-extraction groups showed statistically significant, but clinically limited differences in the perioral area. The Nasolabial angle was significantly larger at T1 in the extraction group compared with the non-extraction group.

Article: Three-dimensional soft tissue changes in orthodontic extraction and non-extraction patients: A prospective study.
Authors: Roberto Rongo, Line Nissen, Cécile Leroy, Ambrosina Michelotti, Paolo M Cattaneo, Marie A Cornelis. Department of Dentistry and Oral Health, Section of Orthodontics, Aarhus University, Aarhus, Denmark and School of Orthodontics, University of Naples ‘Federico II’, Naples, Italy.