3D soft‐tissue evaluation of a Class III treatment with rapid maxillary expander and face mask in pre‐pubertal phase—A retrospective cohort study

Abstract Objectives The aim of this prospective controlled study was to evaluate the effectiveness of the rapid maxillary expander (RME) and face mask treatment using three‐dimensional soft‐tissue facial characteristics of pre‐pubertal Class III children. Setting and Sample Population CLIII and non‐CLIII groups, both of 32 white children aged 6‐8 years participated. Material and Methods Facial surface images were obtained using stereophotogrammetry at T0 and T1 and were superimposed. Landmark‐based and surface‐based facial parameters were measured, and group differences were quantified (ANOVA; P ≥ .05). Results CLIII children had less mid‐face prominence, shorter lower facial height and protruded mandible when compared to non‐CLIII children at T0. At T1, the differences between the groups were not statistically significant, indicating successful correction. After the RME/face mask treatment, the n‐sn and sn‐pg distances increased by 1.5 mm and 2.2 mm, respectively. The distance from sn to the n‐pg line increased by 1 mm, the n‐sn‐pg angle decreased by almost 2°. Pogonion moved downward by 2.5 mm and posteriorly by 3 mm. The surface‐based measurements between the groups after treatment showed anterior movement in the mid‐face region and the upper lip region. The lower lip and chin region moved posteriorly in the CLIII group and anteriorly in the non‐CLIII group. Conclusions After RME/face mask treatment, the lower facial height increased, the maxilla moved anteriorly, and the mandible moved posteriorly. Consequently, CLIII children reached the respective values of the non‐CLIII children, indicating a harmonious facial appearance of CLIII children. The results have been obtained using non‐invasive technique.