Effect of lower incisors inclination on interproximal bone crest in orthodontically treated individuals

Introduction: Lower incisor inclinations can be orthodontically performed for better aesthetic results or to camouflage a skeletal problem. However, when buccolingual tooth movement occurs beyond the adaptive limits of the bone, it is associated with the onset of periodontal problems after treatment. Objective: This study aimed to evaluate the effects of natural and orthodontically induced buccolingual inclination of the lower incisors on the interproximal bone crest (IBC) at the end of orthodontic treatment. Material and Methods: A retrospective analysis of cephalometric and periapical radiographs obtained from the initial (T0) and final (T1) orthodontic documentation of 60 orthodontically treated individuals was performed. The lower incisor inclination in relation to the mandibular plane (IMPA), the thickness of the alveolar process and mandibular symphysis and the height of the IBC were measured. Results: There was no significant change in IMPA during treatment in the evaluated sample. Men had significantly thicker mandibular symphysis than women. A significant reduction was observed in alveolar process thickness and IBC height throughout the sample. Age showed a significant positive correlation with change in IBC height. Although IMPA was not directly correlated with IBC change during treatment, it was indirectly correlated when evaluated in conjunction with other variables. Conclusion: IMPA was not directly related to IBC height change. IMPA, alveolar process thickness and mandibular symphysis together were related to IBC height change.