Soft tissue changes in upper incisors from tooth movements using a new measurement method based on digital scans superimposition in adult patients

OBJECTIVE: To develop a novel digital method to quantify changes in the free gingiva following tooth movement, to measure upper incisor movements by superimposing pre- and post-treatment intraoral scans, and to explore the relationship between tooth movements and gingival changes. MATERIALS AND METHODS: An observational and descriptive-analytical study was conducted on 31 patients, analyzing 124 upper central and lateral incisors. Dental movements (protrusion, retrusion, retroclination, proclination, extrusion, intrusion, rotation, and inclination) and gingival changes (apical or coronal migration) were quantified by superimposing intraoral scans using GOM Inspect and Geomagic Wrap software. RESULTS: Changes in crown proclination were associated with coronal displacement of the clinically visible gingival margin (r = 0.560), whereas changes in crown retroclination were associated with apical displacement (r = - 0.275). A positive association was also observed between apical displacement and age (r = 0.216). No significant associations were found for tipping, rotation, extrusion, or intrusion. CONCLUSIONS: A digital STL-based method was used to quantify crown tooth movement and relative changes in the position of the clinically visible gingival margin. Changes in crown proclination and retroclination were associated with coronal and apical displacement of the gingival margin, respectively, and should be interpreted as correlational findings. CLINICAL RELEVANCE: This digital method allows precise assessment of gingival changes during orthodontic treatment, helping clinicians predict and minimize soft tissue alterations related to incisor movements.