The Impact of Orthodontic Treatment on Pre-Existing Gingival Recessions: A Retrospective Study

(1) Background: This retrospective study aimed to examine the change of gingival recessions (GR) before and after orthodontic treatment (OT). (2) Methods: Patients who had at least one GR on the vestibular surface of maxillary/mandibular teeth mesial to first molars were included. GR was measured on good quality plaster models before and after OT. (3) Results: Significant improvement of mean GR at patient level was found between T0 and T1 (0.45 mm, 95% CI: 0.28, 0.62) (p < 0.001). In 51.4% of patients GRs became better, in 37.8% GRs did not change. and in 10.8% GRs became worse. At tooth level the mean GR improvement was 0.54 mm (CI: 0.42, 0.65; median 0.55 mm Q1; Q3: 0.12, 0.96) (p < 0.001). GR improved in 67 teeth (58.7%), did not change in 41 (36.0%), and worsened in 6 (5.3%). Full healing was observed in 15 teeth. A reduced GR improvement was found in cases with pre-treatment open bite (OR 3.89; CI: 1.35, 11.16; p = 0.008) and dental Class III patients (OR 2.6; CI: 1.11, 6.0; p = 0.026). (4) Conclusions: There was an improvement of GR after OT in more than half of the patients. Class III malocclusion and reduced pre-treatment overbite had a negative impact on GR improvement.