Evaluation of the biomechanical effects of the facemask, bone assisted maxillary protraction and hybrid hyrax + mentoplate combinations method used in the treatment of class iii malocclusions with three dimensional finite element stress analysis

The aim of this study was to examine the different skeletal advance methods used in the treatment of patients with maxillary retrussion as in-vitrro. Three different treatment scenarios were designed on the skull model obtained from the computerized tomography images of a patient with a 10-year-old maxillary retroreflector who was previously treated at the Orthodontics Department of Gaziantep University Dentistry Faculty and finite element analysis done. In the first scenario, rapid maxiller expansion and face maske, in the second scenario bone-assisted maxillary protraction and rapid maxiller expansion, in the third scenario hybrid hyrax + mentoplate combination method was used. As a result of the study, it was found that similar stress distributions were observed in the rapid maxiller expansion/face maske and bone assisted maxillary protraction methods, and these stresses were higher than the hybrid hyrax + mentoplate combination method. As a result, maxillary advencement was found in the maxillary bone-supported maxillary protraction model so that the medial aspect was covered. In hybrid hyrax + mentoplate combination method maxillary protraction was observed at Le Fort I level. In rapid maxillary expansion and facemask model more dentoalveoler protraction was detected than the others. Considering the obtained strain distributions and displacement values, it was observed that the bone-assisted maxillary protraction method provided more skeletal efficacy than the rapid upper maxiller expansion / face mask and hybrid hyrax + mentoplate combination method, due to both the removal of the dental side effects and the advancement of the maxillary protraction.