RESUMEN
PURPOSE: To assess a potential association between lower incisor (LI) position changes during Herbst-multibracket appliance (Herbst-MBA) treatment and the development of labial gingival recessions (LGR). METHODS: All class II patients (Department of Orthodontics, University of Giessen, Giessen, Germany) who had undergone Herbst-MBA treatment until 2015 with study models and lateral cephalograms available from before (T0) and after treatment plus ≥24 months of retention (T3) were included (nâ¯= 259). Lateral cephalograms were evaluated regarding LI position changes: iiL/ML (angle between LI long axis and mandibular plane [MP]), ii-MLPg (distance between LI incisal edge and a line perpendicular to MP through pogonion), apex-MLPg (distance between LI apex and a line perpendicular to MP through pogonion), ii-MLii (distance between LI incisal edge and MP on a line perpendicular to MP through incisal edge). Using study models the distance between the cementoenamel junction and the deepest point of the gingival margin was defined as LGR. RESULTS: The following cephalometric mean changes were recorded (T0-T3): iiL/ML +5.9⯱ 5.76° (pâ¯= 0.929), ii-MLPg -0.2⯱ 0.25â¯mm (pâ¯= 0.430), apex-MLPg +0.1⯱ 0.32â¯mm (pâ¯= 0.363), ii-MLii +0.1⯱ 0.36â¯mm (pâ¯= 0.206). The mean increase of LGR magnitude measured on the study models was 0.1⯱ 0.35â¯mm. However, no association with the cephalometric LI position changes was found (|R|â¯≤ 0.2). CONCLUSION: There is no association between the amount of LI position changes and the development of LGR during Herbst-MBA treatment plus retention. Nevertheless, individual predisposition or excessive treatment changes and extraordinary treatment approaches, respectively, might still lead to development of LGR.