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Updated: Apr 5, 2026
Quantitative Assessment Protocol for Facial Soft Tissue Volumetric Changes with Stereophotogrammetry
Published on: December 9, 2025
Evaluation of soft tissue changes around the lips after bracket debonding using three-dimensional
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.
Orthodontic bracket removal caused slight backward movement in the lower lip and oral commissures, but no significant changes in the upper lip. Three-dimensional (3-D) stereophotogrammetry effectively measured these facial soft tissue changes.
Area of Science:
- Orthodontics
- Facial Aesthetics
- 3D Imaging
Background:
- Orthodontic treatment involves bracket placement and removal.
- Assessing soft tissue changes around the lips post-treatment is crucial for aesthetic outcomes.
- Traditional methods for measuring facial changes have limitations.
Purpose of the Study:
- To evaluate soft tissue alterations around the lips after orthodontic bracket debonding.
- To assess the efficacy of three-dimensional (3-D) stereophotogrammetry in quantifying these changes.
Main Methods:
- Utilized 3-D stereophotogrammetry to capture facial images of 20 subjects before and after bracket removal.
- Superimposed images and analyzed 15 soft tissue landmarks around the lips.
- Performed statistical analysis using paired and independent t-tests.
Main Results:
- No significant changes were observed in the x (left-right) or y (vertical) axes of lip landmarks post-debonding.
- Statistically significant retrusion (changes on the z-axis) was noted in the oral commissures and lower lip.
- Gender and lip thickness did not significantly influence positional changes of most landmarks.
Conclusions:
- Orthodontic bracket debonding resulted in minor retrusion of the oral commissure and lower lip areas.
- The upper lip area showed no significant changes.
- 3-D stereophotogrammetry is a valuable tool for evaluating facial soft tissue dynamics in orthodontic patients.
