Three-dimensional soft tissue evaluation following different maxillary protraction in Class III patient

Abstract

Introduction: This study aimed to comparatively evaluate the effects of three different expansion methods [rapid palatal expansion (RPE), modified alternate rapid maxillary expansion and constriction (Alt-RAMEC), and skeletal anchorage (SA)] combined with maxillary protraction (MP) on the soft tissue profile using 3D stereophotogrammetry.

Methods: A total of 51 patients aged between 8 and 12 years with Class III malocclusion who were in the growth and development period were included in the study. The patients were divided into three groups according to the expansion technique applied. Pre- and post-treatment soft tissue changes were analyzed using 3D stereophotogrammetric images.

Results: Soft tissue measurements revealed significant changes across all groups. Post-treatment volumetric analysis showed significant increases in midface, nasal, and upper lip volumes, alongside reductions in lower lip and chin volumes across all protocols (P < .01). The SA group achieved the highest significant increases in midface (2754 ± 246 mm3), nasal (1156 ± 143 mm3), and upper lip volumes (611 ± 82 mm3) compared with the RPE and Alt-RAMEC groups (P < .01). While alar base width increase was most significant in the RPE group (P < .001), nasal tip protrusion and the greatest decrease in upper lip length and angle were most pronounced in the SA group (P < .05).

Conclusions: SA-supported MP offers the potential to more effectively control soft tissue aesthetics by minimizing undesirable dental and vertical skeletal side effects. This method is superior to other traditional approaches in providing predictable and aesthetically pleasing soft tissue changes.

Keywords: 3D photogrammetry; Alt-RAMEC; RME; face-mask; skeletal anchorage.