The Impact of Damon Self-Ligating Orthodontic Therapy on Soft Tissue and Incisor Inclination: Extraction vs. Non-Extraction Treatment

(1) Background: The present study aimed to evaluate the effects of fixed orthodontic treatment using the Damon self-ligating system on incisor inclination and soft tissue facial profile. Additionally, the study compared the outcomes of premolar extraction versus non-extraction approaches on these parameters. (2) Methods: This retrospective study included 72 patients who were treated with the Damon self-ligating bracket system (Damon, Ormco, Orange, CA, USA). Thirty-five patients (mean age 12.5 years; 20 girls and 15 boys) underwent premolar extraction (Group Ex), while 37 patients (mean age 12.8 years; 16 girls and 21 boys) were treated without extractions (Group NonEx). Lateral cephalometric radiographs were taken pre- and posttherapeutically, and measurements were conducted using OnyxCeph3™ (Image Instruments, Chemnitz, Germany). (3) Results: Following orthodontic treatment, the upper incisors in group Ex were significantly more retruded (p < 0.01), while the mandibular incisors in group NonEx were significantly more proinclined (p < 0.01). Both lips in group Ex, and the upper lip in the group NonEx, exhibited a greater distance from the esthetic line post-therapy (p < 0.01). The position of the lips relative to the SR line did not significantly change in group Ex, whereas group NonEx showed a significantly increased lip protrusion (p < 0.01). A weak negative correlation (−0.37) was observed between the increased retroclination of the upper incisors and the retrusion of the upper lip relative to the SR line. (4) Conclusions: Premolar extraction, as part of a treatment strategy for cases with severe crowding, combined with Damon™ self-ligating braces, does not adversely affect the soft tissue profile.