Evaluation of soft tissue changes around the lips after bracket debonding using three-dimensional stereophotogrammetry
Related Experiment Video
Updated: Apr 5, 2026
Quantitative Assessment Protocol for Facial Soft Tissue Volumetric Changes with Stereophotogrammetry
Published on: December 9, 2025
Young-Kyun Kim1, Nam-Ki Lee2, Sang-Woon Moon3
1a Professor, Department of Oral and Maxillofacial Surgery, Seoul National University Bundang Hospital, Seongnam, and Department of Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
Objective:
To evaluate the changes in soft tissue around the lips after orthodontic bracket debonding using three-dimensional (3-D) stereophotogrammetry.
Materials And Methods:
3-D facial images of 20 subjects (10 men and 10 women; mean age, 26.81 ± 7.23 years) were taken with a white light scanner before and after debonding the labial brackets. Two images acquired from each subject were superimposed, and 15 soft tissue landmarks around the lips were plotted and analyzed. Statistical analysis was performed using both paired and independent t-tests (P < .05).
Results:
There were no significant changes in position of any landmark on the x (left-right)- or y (vertical)-axes after removal of the brackets. However, the landmarks in the oral commissures and lower lip (LLP, -0.55 mm; Li, -0.44 mm; Ch-L, -0.56 mm, all P < .05) on the z (anteroposterior)-axis showed statistically significant differences. There were no significant positional changes of most landmarks on the x-, y-, or z- axes after bracket removal among the various genders and lip thicknesses.
Conclusions:
There was a slight retrusion in the oral commissure and lower lip areas after debonding, but no changes were found in the upper lip area. This study showed that 3-D stereophotogrammetry can be useful in evaluating facial soft tissue changes in orthodontic patients.
