Maxillary Skeletal Expansion with Monocortical and Bicortical Miniscrew Anchorage: A 3D Finite Element Study

Round 1

Reviewer 1 Report

For the future is suggestable to extend the work and test other miniscrews and other materials

Author Response

Response to Reviewer 1

Problem: For the future is suggestable to extend the work and test other miniscrews and other materials.

Reply: Thanks for your comment to improve this manuscript. In future we would extend the work and test other different size miniscrews composed of titanium alloy or stainless steel in current use.

Author Response File: Author Response.docx

Reviewer 2 Report

‘Maxillary Skeletal Expansion with Monocortical and Bicortical Miniscrew Anchorage’ is a numerical study using 3D finite element analysis (FEA) to compare four different insertion scenarios. The authors evaluated transverse displacement and stress distribution (Von Mises equivalent stress) surrounding peri-implant bone to explore optimal miniscrew insertion conditions. The manuscript effectively compares monocortical anchorage with bicortical anchorage for effective anchorage management in orthodontic treatment.

Readers may find this paper interesting.

 

Although I am interested in the topic of this paper because rapid maxillary expansion device using a mini-screw, which has been applied in many recent years, but I found some of the authors' explanations complex and lack of rationale to follow, so it still need a considerable revision to be acceptable for Applied Sciences. I hope this helps to make the paper better.

 

Introduction

It is good that the introduction story is developed without excesses or deficiencies.

 

Method&Results

The method lacks of report of any analytical quality assurance measurement, which is in particular of finite element model condition (how to make CAD data using CBCT data (because CBCT data have no CT value), homogenized model or not, size of elements, number of nodes and elements, etc), precise boundary conditions (fixed whole blue plane or only triangle arrow-heads), transverse displacement conditions (I couldn’t understand the definition of ‘step 1-20’). These are the important conditions for accurate FEA, so authors should describe more precise data in this experiment. Furthermore, I think it should be examined whether the stress evaluation method is appropriate. It is unclear that the assessment method of Von Mises equivalent stress, Definitely, the value (MPa) and distribution (%) were described in Results and the mean values of Von Mises stress are described in Table 3. However, it doesn’t seem to be reproducible because there’s no description about method of calculation. So, it is not appropriate for stress quantitative evaluation. Please add the calculation method of these parameters.

 

Discussion

P6

Since detailed biomechanical comparisons between bi-cortical and monocortical anchorage systems are rarely available in the literature, the ob-jective of this study was to address this gap in the literature.

Reference 12, which is discusses the usefulness of bi-cortical in 3DFEM, so please add that as a reference, at least. There are several other similar papers that should be added.

 

4.1

"Since miniscrews are not osseointegrated,"

There are several views on osseointegration, please add a paper that proves this.

 

4.2

"Therefore, a parallel opening of the midpalatal suture differs from those induced by a conventional rapid palatal expansion,"

Please add a paper and explain where is the evidence that a conventional rapid palatal expansion shows a parallel opening of the midpalatal suture.

 

4.3

"Instead of titanium alloy, stainless steel was the selected miniscrew composition because it has superior toughness (resistance to fracture) when placed in a relatively dense cortical bone."

Please add a paper to this as well showing what physical properties stainless steel exhibits.

 

5. Conclusion

The inclusion statement is not consistent with the purpose of this paper.

The inclusion does not refer to differences in materials, or It also does not mention stress distribution and displacement during MARME. Please correct.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

In the materials and methods all analyzed subjects should be described. The research areas appear in the results section, but need to be explained in the previous parts.

The position of analyzed implants in Figure 3 are not explain in details in the manuscript text, especially the long and the short one where placed – in anterior or posterior position? The graphic is ambiguous. Change it, please.

Author Response

Response to Reviewer 3

Problem: In the materials and methods all analyzed subjects should be described. The research areas appear in the results section, but need to be explained in the previous parts.

Reply: Thanks for your comment to improve this manuscript. The manuscript of the materials and methods has been corrected in detail, particular in the skull model reconstruction and the miniscrew anchorage system of the FEA model. 

 

Problem: The position of analyzed implants in Figure 3 are not explain in details in the manuscript text, especially the long and the short one where placed – in anterior or posterior position? The graphic is ambiguous. Change it, please.

Reply: Thanks for your comment to improve this manuscript. The Figure 3 is corrected to show the four types of the miniscrew models including the model A of monocortical anchorage: monocortical miniscrew with 6 mm in length located at the posterior and anterior position, the model B of monocortical deepening anchorage: monocortical miniscrew with 8 mm in length located at the posterior and anterior position, the model C of bicortical anchorage: bicortical miniscrew with 10 mm in length located at the posterior position and 12 mm in length located at the anterior position, and the model D of bicortical deepening anchorage: bicortical miniscrew with 14 mm in length located at the posterior position and 16 mm in length located at the anterior position.    

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The author answered my comments chiefly appropriately.