Objectives
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.
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.