Abstract
An article published on July 6, 2020 by Thakkar et al aims to use digital workflow to print a 3D digital miniscrew-assisted rapid palatal expander (MARPE) with the aid of cone beam computed tomography, which would overcome the deficiencies of a prefabricated MARPE design and would provide greater rigidity and anchorage value and predictable skeletal expansion (Thakkar D, Ghosh A, Keshwani T. Digital workflow for cone beam computed tomography (CBCT)-guided customized 3D digital mini screw-assisted rapid palatal expansion: A clinical innovation. J Indian Orthod Soc. 2020;54(3):262–266).
We have come across certain doubts. Kindly respond to the same.
In Figure 2 (p. 263) and Figure 4 (p. 264), the pretreatment stereolithography (STL)[A]:Author: Please provide expansions for the following: STLCBCT files of the intraoral scan and the pretreatment CBCT image of the maxilla are shown, which are further used for superimposition in the next step. It is very disturbing to note that CBCT of maxilla (Figure 4) does not match the digital models and STL file (Figures 2 and 3). It seems that CBCT is of a different patient. Kindly explain the variation.
Under the heading, Need for Customization of MARPE (p. 263), it is mentioned that customization of MARPE leads to better fit and adaptation (Figure 1). However, the fit and adaptation of hyrax screw depend on its size and location.
In Figure 13 (p. 265), post-expansion superimposition image of CBCT over digital models is shown. It can be observed from this figure that there is differential expansion after using 3D digital MARPE which is evident as a scissors bite on the left side and a crossbite on the right side. Kindly explain.