PHOTOMETRIC AND CLINICAL EVALUATION OF SOFT TISSUE PROFILE CHANGES AFTER ORTHODONTIC TREATMENT

Abstract

Objective: This study aimed to quantitatively evaluate soft tissue profile changes in patients undergoing orthodontic treatment, comparing extraction and non-extraction modalities, using a standardized photometric analysis, and to correlate these findings with clinical aesthetic outcomes. Methods: A retrospective cohort study was conducted on 80 patients (40 extraction, 40 non-extraction) who completed comprehensive orthodontic treatment. Standardized lateral photographs were taken before treatment (T1) and after treatment (T2). Photometric analysis was performed using digital software to measure key soft tissue landmarks and angular/linear measurements, including the Nasolabial Angle (NLA), Mentolabial Angle (MLA), E-Line (Ricketts), and Z-Angle (Merrifield). Changes within and between groups were statistically analyzed using paired and independent t-tests (p < 0.05). Results: Both groups showed statistically significant improvements in profile aesthetics. The extraction group demonstrated a significant increase in the NLA (mean +5.2°) and a substantial retrusion of both upper and lower lips relative to the E-Line (mean change -2.8 mm). The non-extraction group exhibited more subtle changes, with a primary improvement in lip competence and a slight increase in the NLA (mean +1.4°). Significant differences were found between the groups for all lip position variables. Conclusion: Orthodontic treatment induces significant and predictable changes in the soft tissue profile. Photometric analysis is a reliable, non-invasive, and clinically valuable tool for quantifying these changes. Extraction-based treatments produce more pronounced profile retrusion compared to non-extraction modalities. These findings underscore the necessity of incorporating detailed soft tissue analysis into orthodontic diagnosis and treatment planning to achieve optimal facial harmony.