Soft tissue changes during orthopedic therapy: An in vivo 3-dimensional facial scan study

The aim was to compare the soft tissue changes in pretreatment and posttreatment facial scans of patients who had undergone various orthopedic treatments vs a control group of untreated growing patients.

Facial scans were performed before (T0) and after (T1) orthopedic treatment in 15 patients prescribed rapid palatal expander (RPE), 15 cervical headgear (HG), and 15 facemasks (FM), as well as 6 months apart in 15 untreated growing patients. After best-fit scan alignment using Geometric Control X software (3D Systems Inc, Rock Hill, SC), a 3-dimensional (3D) analysis of soft tissue changes was performed, comparing 3D reference points (total 22) and 8 areas on T0 and T1 scans. Kruskal-Wallis nonparametric tests and pairwise comparison with Bonferroni's correction were applied to identify any statistically significant differences among groups (P <0.05). All analyses were conducted with SPSS software (version 28; IBM, Armonk, NY).

At T1, reduced soft tissue projection was found at the nose and upper lip in the HG group, the lower lip in the HG and RPE groups, and the chin in the FM and RPE groups. The RPE group displayed a statistically significant increase in facial divergence, confirmed by gnathion position (RPE vs FM [P = 0.018] and RPE vs control [P = 0.046]), as well as an increase in the soft tissue projection of both cheeks (left cheek in range of 1-2 mm [P = 0.030] and range of 0 to -1 mm [P = 0.022]; right cheek in range of 1-2 mm [P = 0.003] and range -1 to -2 mm [P = 0.001]). There were no clinically significant differences among groups in mandibular right and left body areas.

The 3D facial analysis revealed significant differences in soft tissues among orthopedic treatments, especially at the upper and lower lip and chin areas, as compared with untreated patients.