Movement pattern evaluation of molars, incisors, and lip changes in cases of bimaxillary dental distalization anchored in extra-alveolar mini-implants and cases of extraction of premolars in Angle Class I bi protrusion patients

Abstract

Maxillomandibular dental biprotrusion is characterized by Angle Class 1 malocclusion with buccal upper and lower incisors, protruding lips, decreased nasolabial angle, and convex lower facial profile. Treatment options include orthodontic treatment with anterior teeth retraction after the first four premolars extraction, surgical orthodontic treatment, and bimaxillary distalization with skeletal anchorage. However, the decision to extract or not, and which teeth will be extracted is still controversial. The objectives of this study will be, first, to perform finite element analysis (FEA) of mandibular total dental distalization anchored in an extra alveolar mini implant. The results of this study will evaluate, in a randomized clinical trial, the effects of maxillomandibular dental distalization anchored in extra-alveolar mini-implants in Class I bi protrusive individuals. Questionnaires will be applied to assess the perception of aesthetics, pain and comfort of individuals. Finally, will be compared the effects of maxillomandibular biprotrusion in Class I individual correction between treatments with 4 premolars extraction and mass retraction (ER group) and retraction in two stages (TSD group), and treatment with maxillomandibular dental distalization using extra alveolar bone anchorage (EAD group). The averages between T1 and T2 will be submitted to Student's T-test to assess dental and cephalometric changes after correction of maxillomandibular dental biprotrusion with retraction anchored in extra-alveolar mini-implants. Pearson's correlation will be applied to assess the correlation between treatment time and the amount of molar distalization and incisor retraction, in both arches. The comparison between the cephalometric averages of the ER, TSD, and EAD groups before (T0) and after (T4) the treatment will be performed using the ANOVA test. (AU)