Associação entre a inclinação de incisivos inferiores e as espessuras do processo alveolar e da sínfise mandibular no desenvolvimento de recessão gengival

Abstract

Introduction: Retrospective studies have shown conflicting results regarding the association between lower incisor inclination performed during orthodontic treatment and the development of gingival recession (GR). Objective: This study aimed to evaluate the association between lower incisor inclination and alveolar process and mandibular symphysis thickness in the development of gingival recession. Material and Methods: In this study of retrospective cohort, 60 individuals who had frontal intraoral photography and cephalometric radiography performed before (T0) and after orthodontic treatment (T1) were evaluated. The GR was considered present when the lower incisors cementoenamel junction was visualized in the frontal intraoral photograph. Improvement circumstances, stability and worsening of the gingival condition were determined, respectively, by the reduction, maintenance and increase of the number of lower incisors with GR. Plane Angle Mandibular Incisor (IMPA) and the thicknesses of the alveolar process and mandibular symphysis were defined on cephalometric radiographs. Results: Men had significantly thicker mandibular symphysis than women at T0 and T1 (p<0.0004). The thickness of the alveolar process has shown significant reduction of approximately 10% during orthodontic treatment (p<0.0001). Among individuals with at least 1 lower incisor with RG at the beginning of orthodontic treatment, most obtained improvement (50%) and stability (21.4%) of gingival condition during orthodontic treatment and the minority obtained worsening (28.6%). Among individuals without RG at T0, 70.4% presented stability ofthe gingival condition. 16 lateral incisors presented worsening gingival condition, 129% more when compared to central incisors. Conclusion: It has been found no association between lower incisor inclination and alveolar process, and mandibular symphysis thickness in the development of GR.