Round 1

Reviewer 1 Report

Comments to the authors

 

Thank you for inviting me to review the paper entitled “T-scan novus system application – digital occlusion analysis of 3D printed orthodontics retainers”. 

The study assess the occlusal force of 3D printed ortho retainers, and found that despite the indication of the software is to achieve homogeneous contacts, the force applied is actually different, with higher forces expressed distally. The study presents many flaws (see below for the details). 

 

Major concerns:

The study presents with many flaws, some more important than others, which do not allow for accepting the publication.

1) It is not clear why the aim to examine the occlusal forces of the ortho retainer, as the introduction does not mention what is not known in the literature and why it is important to assess. Nor it is clear why they are utilizing a 3D printed materials, especially because there is no control group with traditional material 

2) parts are confused and not appropriately placed in the manuscript (e.g. results put into the methods)

3) the methodology has major flaws, e.g. sample size calculation missing, small sample size that is not known if it also permits any statistical inference

4) discussion is out of the scope of the article and lacks acknowledgement of the limitations, which are several 

 

 

Abstract: this is too long (316 words) and not within the word limit according to the author guidelines of the journal (200 words). The authors need to drastically cut it and fit within the allowed number of words. 

- what is refer to female and male is not gender, but sex (or biological sex)

 

Introduction: the introduction is too long and discuss topics that are out of the scope of this article (e.g, the introduction should focus on why the authors propose 3D printed orthodontic retainers vs the traditional ones). The part on the removable retainers can be omitted as the study does not address removable appliances. Similarly, I also suggest that the authors omit the part of the removal of support material. The introduction should be concise, short and right to the point to introduce the gap in the literature that justifies why the study has been conducted. 

- when the authors discuss about AI software in orthodontics, the paragraph seems only to discuss one study. However, I suggest that the author better summarize the use of AI in ortho so far. For example, correctly the authors identified its use with ceph analysis; however, systems of AI have been largely developed and studied that follow patients during ortho treatment on oral hygiene (e.g., 10.1186/s12903-021-01793-9) and also during ortho retention phase (e.g. doi. 10.4041/kjod.2022.52.2.123). A recent systematic review also addresses its application: doi 10.1177/14653125231178040. I suggest that the authors include some of these, or that anyway expand their applications.

- the introduction does not conduct the reader to the aim of the study and to the problem. Why is it worthy to examine the distribution of the occlusal force with 3D ortho retainers? And also, what is known on forces applied when traditional ortho retainers have been used? This is the base of the all study, and I encourage the authors to provide a compelling reason why the study has been done, which should be perceived in the introduction. 

 Methods:

- this first paragraph contains the Results, and not the Methods. 

- the statistical analysis part is normally isolated in a subsection called Statistical analysis 

- more details need to be presented: when was the measurement performed? At the delivery of the appliance? by the same calibrated examiner? was it a new device delivered on the day of the debonding? The methods section should be able to describe with details the procedure so that the methods can be reproducible 

- it is not clear if the system of force detection occurs when the teeth are contacting. IF this is the case, then it is understandable and predictable that molars and posterior teeth will express higher forces than the anterior section. Why did the authors expect different results? 

 

Discussion: 

- the paragraph (page 9 lines 318 on) on ADHD does not fit in the flow and within the topic, especially the explanation of what ADHD is. 

- I believe the discussion is out of the scope of the study. The discussion should elaborate and speculate about the findings, and compare this with what is available in the literature. 

At the end of the manuscript, unfortunately, it is not clear why the authors utilized 3D printed ortho retainers; what they were expected to observe from the study (i.e., Null Hypothesis), and why they found a different result. 

 

Comments for author File: Comments.pdf

English is fine and understandable 

Author Response

REVIEW 1 – RESPONSE

 

Thank you for inviting me to review the paper entitled “T-scan novus system application – digital occlusion analysis of 3D printed orthodontics retainers”.

The study assess the occlusal force of 3D printed ortho retainers, and found that despite the indication of the software is to achieve homogeneous contacts, the force applied is actually different, with higher forces expressed distally. The study presents many flaws (see below for the details).

 

Major concerns:

The study presents with many flaws, some more important than others, which do not allow for accepting the publication.

• It is not clear why the aim to examine the occlusal forces of the ortho retainer, as the introduction does not mention what is not known in the literature and why it is important to Nor it is clear why they are utilizing a 3D printed materials, especially because there is no control group with traditional material
• parts are confused and not appropriately placed in the manuscript (e.g. results put into the methods)
• the methodology has major flaws, e.g. sample size calculation missing, small sample size that is not known if it also permits any statistical inference
• discussion is out of the scope of the article and lacks acknowledgement of the limitations, which are several

 

 

Abstract: this is too long (316 words) and not within the word limit according to the author guidelines of the journal (200 words). The authors need to drastically cut it and fit within the allowed number of words.

The abstract was abbreviated. Thank you!

• what is refer to female and male is not gender, but sex (or biological sex)

It was changed. Thank you!

 

Introduction: the introduction is too long and discuss topics that are out of the scope of this article (e.g, the introduction should focus on why the authors propose 3D printed orthodontic retainers vs the traditional ones). The part on the removable retainers can be omitted as the study does not address removable appliances. Similarly, I also suggest that the authors omit the part of the removal of support material. The introduction should be concise, short and right to the point to introduce the gap in the literature that justifies why the study has been conducted.

The study refers to removable retainers, which are digitally designed. Other parts of the introduction were removed. Thank you!

 

• when the authors discuss about AI software in orthodontics, the paragraph seems only to discuss one study. However, I suggest that the author better summarize the use of AI in ortho so far. For example, correctly the authors identified its use with ceph analysis; however, systems of AI have been largely developed and studied that follow patients during ortho treatment on oral hygiene (e.g., 1186/s12903-021-01793-9) and also during ortho retention phase (e.g. doi. 10.4041/kjod.2022.52.2.123). A recent systematic review also addresses its application: doi 10.1177/14653125231178040. I suggest that the authors include some of these, or that anyway expand their applications.

 

The information was added! Thank you!

• the introduction does not conduct the reader to the aim of the study and to the Why is it worthy to examine the distribution of the occlusal force with 3D ortho retainers? And also, what is known on forces applied when traditional ortho retainers have been used? This is the base of the all study, and I encourage the authors to provide a compelling reason why the study has been done, which should be perceived in the introduction.

Thermoformed retainers have the same thickness in all directions. With them, preliminary contacts always occur, mainly in the distal area. Therefore, we only investigated printed retainers with digitally distributed balanced contacts.

 

Methods:

• this first paragraph contains the Results, and not the

It was moved. Thank you!

• the statistical analysis part is normally isolated in a subsection called Statistical

The information was added! Thank you!

• more details need to be presented: when was the measurement performed? At the delivery of the appliance? by the same calibrated examiner? was it a new device delivered on the day of the debonding? The methods section should be able to describe with details the procedure so that the methods can be

The information was added! Thank you!

• it is not clear if the system of force detection occurs when the teeth are contacting. IF this is the case, then it is understandable and predictable that molars and posterior teeth will express higher forces than the anterior Why did the authors expect different results?

It is a digitally balanced occlusion, not a natural dentition. Therefore, we expected different results.

Discussion:

• the paragraph (page 9 lines 318 on) on ADHD does not fit in the flow and within the topic, especially the explanation of what ADHD

This part was removed. Thank you!

• I believe the discussion is out of the scope of the The discussion should elaborate and speculate about the findings and compare this with what is available in the literature.

At the end of the manuscript, unfortunately, it is not clear why the authors utilized 3D printed ortho retainers; what they were expected to observe from the study (i.e., Null Hypothesis), and why they found a different result.

Unfortunately, we did not find any other study that investigated the occlusion of printed retainers.

 

THANK YOU FOR YOUR ADVICE!

Author Response File: Author Response.pdf

Reviewer 2 Report

 Comments to authors

The authors of the paper mainly concentrate on “T-Scan Novus system application – Digital Occlusion Analysis of 3D Printed Orthodontics Retainers” There are some experimental concerns in this manuscript.

Abstract

The background section is too long.

The information you put in the material section should be removed and added to the result section

However, the abstract is still not structured so well to provide a strong summary of this study. For example, the argument on why this study is necessary and important is not clear and the findings from this study were missing in the abstract.

The introduction is too long and the rationale of the paper is needed to rewrite.

In Methodology, this section is insufficient in details and does not allow the reader to understand why and how the study was conducted.

The results should be presented in a clearer way. Perhaps a correlation matrix to show the strength of the various relations could be employed.

The results are presented with no logical sequence and it is very hard to understand them therefore I can’t give many comments on this section. This section needs to be rewritten entirely with numeric results.

The discussion is very shallow and there is no critical thinking. It is mainly a repetition of the results with some superficial observations related to other studies. It has no logical order its scope is very wide (diagnosis, treatment plan, and prognosis).

Conclusions: No conclusions can be drawn from this study in my opinion and the main concern is that the conclusion does not reflect the results nor the goal of the study. The author should really re-think the aim of the study and how this study contributes to the field.

Author Response

REVIEW 2 – RESPONSE

 

The authors of the paper mainly concentrate on “T-Scan Novus system application – Digital Occlusion Analysis of 3D Printed Orthodontics Retainers” There are some experimental concerns in this manuscript.

 

Abstract

The background section is too long.

The background was abbreviated. Thank you!

The information you put in the material section should be removed and added to the result section.

It was moved. Thank you!

However, the abstract is still not structured so well to provide a strong summary of this study. For example, the argument on why this study is necessary and important is not clear and the findings from this study were missing in the abstract.

This part was rewritten. Thank you!

The introduction is too long and the rationale of the paper is needed to rewrite.

The background was abbreviated. Thank you!

In Methodology, this section is insufficient in details and does not allow the reader to understand why and how the study was conducted.

The information was added. Thank you!

The results should be presented in a clearer way. Perhaps a correlation matrix to show the strength of the various relations could be employed.

The results are presented with no logical sequence and it is very hard to understand them therefore I can’t give many comments on this section. This section needs to be rewritten entirely with numeric results.

The information was added. Thank you!

The discussion is very shallow and there is no critical thinking. It is mainly a repetition of the results with some superficial observations related to other studies. It has no logical order its scope is very wide (diagnosis, treatment plan, and prognosis).

Unfortunately, we did not find any other study that investigated the occlusion of printed retainers.

Conclusions: No conclusions can be drawn from this study in my opinion and the main concern is that the conclusion does not reflect the results nor the goal of the study. The author should really re-think the aim of the study and how this study contributes to the field.

This part was rewritten. Thank you!

 

THANK YOU FOR YOUR ADVICE!

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Authors,

thank you for this interesting paper. Here are some suggestions:

1. Please, write in the introduction, that retention is not only the crucial, but the final stage of treatment

2. In the introduction, please add the information on a huge problem with fixed reteiners which is MRI examination - please, add the information on the possible disadvantages of this method, eg.:

- Neela PK, Tatikonda VK, Syed MW, Mamillapalli PK, Sesham VM, Keesara S. Influence of orthodontic brackets and permanent retainers on the diagnostic image quality of MRI scans: A preliminary study. Dent Med Probl. 2021;58(4):499–508. doi:10.17219/dmp/132390

3. Actually, wrap around retainer is an original version of Hawley plate - the one on the Adams clasps is modification. Please, correct that

4. In the discussion, you should add more 3D materials used for retainer fabrication, eg. Dental LT Clear - please, add to the discussion such aspect as:

- effects of polishing and artificial aging on mechanical properties of splints

- effects of influence of compression and tensile tests on the mechanical properties of the 3D materials

- exposition to tests and the fractal and textural differences - if they change while used, eg. Paradowska-Stolarz, A.; Wieckiewicz, M.; Kozakiewicz, M.; Jurczyszyn, K. Mechanical Properties, Fractal Dimension, and Texture Analysis of Selected 3D-Printed Resins Used in Dentistry That Underwent the Compression Test. Polymers 2023, 15, 1772. https://doi.org/10.3390/polym15071772

5. In the discussion, you should add limitations of this study

The paper in general is well prepared and the topic is novel, developing, so beside those aspects, I rate the article high.

 

Author Response

REVIEW 3 – RESPONSE

 

Dear Authors,

thank you for this interesting paper. Here are some suggestions:

1. Please, write in the introduction, that retention is not only the crucial, but the final stage of treatment.

It was changed. Thank you!

2. In the introduction, please add the information on a huge problem with fixed reteiners which is MRI examination - please, add the information on the possible disadvantages of this method, eg.:

- Neela PK, Tatikonda VK, Syed MW, Mamillapalli PK, Sesham VM, Keesara S. Influence of orthodontic brackets and permanent retainers on the diagnostic image quality of MRI scans: A preliminary study. Dent Med Probl. 2021;58(4):499–508. doi:10.17219/dmp/132390

The information was added. Thank you!

3. Actually, wrap around retainer is an original version of Hawley plate - the one on the Adams clasps is modification. Please, correct that!

It was changed. Thank you!

4. In the discussion, you should add more 3D materials used for retainer fabrication, eg. Dental LT Clear - please, add to the discussion such aspect as:

- effects of polishing and artificial aging on mechanical properties of splints

- effects of influence of compression and tensile tests on the mechanical properties of the 3D materials

- exposition to tests and the fractal and textural differences - if they change while used, eg. Paradowska-Stolarz, A.; Wieckiewicz, M.; Kozakiewicz, M.; Jurczyszyn, K. Mechanical Properties, Fractal Dimension, and Texture Analysis of Selected 3D-Printed Resins Used in Dentistry That Underwent the Compression Test. Polymers 2023, 15, 1772. https://doi.org/10.3390/polym15071772

The information was added. Thank you!

5. In the discussion, you should add limitations of this study

This section was added. Thank you!

 

The paper in general is well prepared and the topic is novel, developing, so beside those aspects, I rate the article high.

 

THANK YOU FOR YOUR ADVICE!

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Revision:

 

Although the authors have provided a revision of their study, I still have major concerns in suggesting this paper for publication. The statistical analysis is not correct and does not even mention which statistical tests have been used to draw conclusions on the difference of forces. Another underlying major concern is that the authors reflect on the fact that the retainers, despite providing diffuse and homogeneous contacts on all the teeth, have different occlusal forces. These are higher in the distal segments. However, doesn’t it just reproduce what physiologically happen in the natural arches? Who would want the same forces applied to the incisors and to the molars? The authors have to strongly justify why the fact that there is an unbalanced occlusal force distribution is something to be careful about, as this just reflects the normal occlusion.

 

Some other comments are here expressed: 

 

Abstract: the conclusions of the abstract are still not a logical summary of the results. In the results, nothing is said about the fact that there is an equal distribution of the contacts. It is only mentioned the different force distribution. The authors need to add it to the results, if they want the conclusions to be a good summary and reflect the findings. 

 

 

Introduction: the introduction is still confusing, and the flow is not logic. First of all, the authors introduce the advantages of digitalization in dentistry (1^st paragraph). Then, they discuss about retainer, and types of removable  - results of studies on satisfaction – and then fixed retainer. Then there is a paragraph that presents the situation when the orthodontic treatment includes an impacted tooth (and I would personally remove this, as it does not add any significant information for the study). Then, the introduction switches to talk about the digital technologies producing aligners. However, these aligners do not seem to be retainers. Then, there is a passage presenting the fully digital protocol, the occlusal thickness and occlusal analysis, and finally occlusal forces. 

In summary, the introduction seems to touch upon multiple items that do not directly drive the attention of the reader towards the aim of the study and the significance of the study. I already pointed out this concern in my previous review, and still the introduction contains all these aspects and discussions. I suggest that the authors carefully think about a logic flow of the introduction and consistently follow it. 

 

methods: the table 1 should be presented in the results, not in the methods. This was already pointed out in my previous review.

 

statistical analysis: there is no indication of the statistical tests utilized to draw inferential statistics on the 21 participants. 

 

results: page 9, lines 315-322 report that there is a statistically significant difference. However, no p values are indicated nor in the text nor in the table (nor there was any indication in the statistical analysis section on how this would have been achieved). 

 

conclusions: these are accurate in reflecting the findings of the study.  

Comments for author File: Comments.docx

None

Author Response

REVIEW 1 – RESPONSE

 

Revision:

 

Although the authors have provided a revision of their study, I still have major concerns in suggesting this paper for publication. The statistical analysis is not correct and does not even mention which statistical tests have been used to draw conclusions on the difference of forces. Another underlying major concern is that the authors reflect on the fact that the retainers, despite providing diffuse and homogeneous contacts on all the teeth, have different occlusal forces. These are higher in the distal segments. However, doesn’t it just reproduce what physiologically happen in the natural arches? Who would want the same forces applied to the incisors and to the molars? The authors have to strongly justify why the fact that there is an unbalanced occlusal force distribution is something to be careful about, as this just reflects the normal occlusion.

Yes, you are right, this is typical of natural dentition. In the digital design, it was assumed that the retainer would be in complete contact with the antagonists, so we thought there would be a difference. Thank you for the clarification!

 

Some other comments are here expressed:

 

Abstract: the conclusions of the abstract are still not a logical summary of the results. In the results, nothing is said about the fact that there is an equal distribution of the contacts. It is only mentioned the different force distribution. The authors need to add it to the results, if they want the conclusions to be a good summary and reflect the findings.

The abstract was changed. Thank you!

 

Introduction: the introduction is still confusing, and the flow is not logic. First of all, the authors introduce the advantages of digitalization in dentistry (1^st paragraph). Then, they discuss about retainer, and types of removable  - results of studies on satisfaction – and then fixed retainer. Then there is a paragraph that presents the situation when the orthodontic treatment includes an impacted tooth (and I would personally remove this, as it does not add any significant information for the study). Then, the introduction switches to talk about the digital technologies producing aligners. However, these aligners do not seem to be retainers. Then, there is a passage presenting the fully digital protocol, the occlusal thickness and occlusal analysis, and finally occlusal forces.

In summary, the introduction seems to touch upon multiple items that do not directly drive the attention of the reader towards the aim of the study and the significance of the study. I already pointed out this concern in my previous review, and still the introduction contains all these aspects and discussions. I suggest that the authors carefully think about a logic flow of the introduction and consistently follow it.

The mentioned information was removed. Thank you!

 

methods: the table 1 should be presented in the results, not in the methods. This was already pointed out in my previous review.

In the previous revision, the table was divided into demographics and clinical characteristics, and both parts were placed in methods and results, respectively. After the second edit, the entire table was moved to results. Thank you!

 

statistical analysis: there is no indication of the statistical tests utilized to draw inferential statistics on the 21 participants.

Additional statistical analysis was made. Thank you!

 

results: page 9, lines 315-322 report that there is a statistically significant difference. However, no p values are indicated nor in the text nor in the table (nor there was any indication in the statistical analysis section on how this would have been achieved).

Tables 3 and 4 were changed with additional information. Thank you!

 

conclusions: these are accurate in reflecting the findings of the study.  

 

THANK YOU FOR YOUR ADVICE!

 

Author Response File: Author Response.docx

Reviewer 2 Report

Dear author... I hope that you will receive my comment and you are in the best condition ... I found that you have adhered to all the notes that were referred to before and the research has become better ... Greetings

Author Response

Thank you very much for your wishes! I wish you a lot of professional and personal success!