Related Experiment Video
Updated: May 19, 2026
Quantitative Assessment Protocol for Facial Soft Tissue Volumetric Changes with Stereophotogrammetry
Published on: December 9, 2025
Three-dimensional evaluation of changes in lip position from before to after orthodontic appliance removal
Lindsey Eidson1, Lucia H S Cevidanes, Leonardo Koerich de Paula
1Department of Orthodontics, University of North Carolina, Chapel Hil, USA. lindseyeidsondds@gmail.com
Introduction:
Our objectives were to develop a reproducible method of superimposing 3-dimensional images for measuring soft-tissue changes over time and to use this method to document changes in lip position after the removal of orthodontic appliances.
Methods:
Three-dimensional photographs of 50 subjects were made in repose and maximum intercuspation before and after orthodontic appliance removal with a stereo camera. For reliability assessment, 2 photographs were repeated for 15 patients. The images were registered on stable areas, and surface-to-surface measurements were made for defined landmarks.
Results:
Mean changes were below the level of clinical significance (set at 1.5 mm). However, 51% and 18% of the subjects experienced changes greater than 1.5 mm at the commissures and lower lips, respectively.
Conclusions:
The use of serial 3-dimensional photographs is a reliable method of documenting soft-tissue changes. Soft-tissue changes after appliance removal are not clinically significant; however, there is great individual variability.
