Influence of changing various parameters in miniscrew-assisted rapid palatal expansion: A three-dimensional finite element analysis

Abstract

Objective This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM). Methods In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE. Results When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes. Conclusions The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

Complications reported with the use of orthodontic miniscrews: A systematic review

“…Taken together with the current literature, our findings suggest that the anterior region of the palate is the most appropriate insertion site owing to the high success rate and ideal anatomical characteristics. 53 - 56 However, unintentional injuries to the roots of the anterior teeth were reported in 2 studies. 16 , 27 In these studies, root damage occurred because of improper positioning, with the placement of the miniscrews at the second palatine rugae or ahead.…”

Deformation of the circummaxillary sutures during acute micro‐implant assisted rapid palatal expansion and tooth‐supported expansion: An ex vivo study

“…Comparing the results with finite element model (FEM), the zygomaxillary suturein a human model represented a important stress zone in all micro‐implant position and length 35 . Moreover, sagittal displacement of the maxilla was dependent of micro‐implant position and length and may present positive or negative values (compression or traction) 35 .…”

“…32,33 The MPS was the only disarticulated suture after activations in this experiment, with a mean tension value of 5639.16 με, ( Comparing the results with finite element model (FEM), the zygomaxillary suturein a human model represented a important stress zone in all micro-implant position and length. 35 Moreover, sagittal displacement of the maxilla was dependent of micro-implant position and length and may present positive or negative values (compression or traction). 35 In a second human FEM study, it was observed more stress and displacement in the maxilla-zygomatic suture then maxilla pterygoid-process suture, 36 these results were very similar in this research.…”

Stress and displacement of mini-implants and appliance in Mini-implant Assisted Rapid Palatal Expansion: analysis by finite element method

“…Additionally, a previous FEM study identified that, in terms of stress distribution and transverse displacement, four mini-implants are preferable. 17 …”