3D-Printed Accessories and Auxiliaries in Orthodontic Treatment
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsPlease see my attachment.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
Thank you very much for your insightful comments. Hereinbelow we address your concerns and suggestions one by one, and we hope we have met your expectations in doing so:
Comment 1: Line 20, future outlook should be collapsed with the abstract.
Response 1: Thank you for the suggestion. The "future outlook" section has been merged with the abstract as requested.
Comment 2: Line 68, by comparing blue and grey bars over the year, is Fig.1 indicating that the need of general implantology is bypassing that of orthodontics? This conclusion seems to
contradict the dental application is a critical role in 3DP, please explain this, or maybe
change some other more supportive data
Response 2: Thank you for pointing this out. We have addressed this by revising the text to explicitly acknowledge that implantology is projected to surpass orthodontics in total market share in later years, as shown in Figure 1. However, orthodontics maintains its crucial role in this field. We believe this revised wording aligns with the data trends and ensures clarity in our argument.
Comment 3: Line 148, in regarding to the publications collected, I recommend the authors modify the title of the manuscript by indicating that this study is based on the published data in the interval of year 2020-2024
Response 3: Thank you for your thoughtful suggestion regarding the title modification to reflect the inclusion of publications from the interval 2020–2024.
Please kindly allow us to respectfully elucidate our original thinking process: We found that there is very limited evidence on this topic prior to 2020, so we did not originally feel this as a limiting date. Another aspect we considered is the fast-moving changes in this field, somewhat possibly diminishing the significance of some older articles. For example, during every single year between 2022 and 2024 there were produced more articles on this topic than the combined total of all years prior to 2020. The selected timeframe 2020-2024 was chosen to ensure the inclusion of relevant and contemporary studies that reflect advancements in this rapidly evolving field while avoiding being distracted by outdated methods. Given this context, please kindly consider our perspective and we respectfully ask if you feel the modification is still necessary, or if the current title remains appropriate?
Comment 4: Line 175, a total of 582 articles are picked out from PubMed and Google Scholar bases, are there any papers overlapped? How many papers are exclusively indexed in PubMed but not Google Scholar? It is interesting that the authors picked the two databases, I think it may be a benefit to claim why PubMed is chose.
Response 4: Thank you for your valuable observation regarding the overlap of articles from PubMed and Google Scholar, as well as your suggestion to clarify the choice of databases. Regarding the paper overlapping, in the final selection of reviewed articles we identified 33 overlapping articles between the two databases, and 25 papers were exclusively indexed in PubMed but not in Google Scholar. PubMed was selected due to its robust indexing of high-quality biomedical literature, which is highly relevant to the focus of our review. Google Scholar, on the other hand, was chosen to ensure comprehensive coverage by including additional articles that may not be indexed in PubMed but still contribute valuable insights to the field. We aimed to combine the strength of them both to reach a higher potential. We included a clarification in the manuscript to highlight the rationale behind the selection of these databases and provide a breakdown of the overlapping and exclusive articles, as you suggested.
Comment 5: Line 217, please reformat Fig. 2 delicately, in the current form, the arrows are placed in a very casual way
Response 5: We appreciate you calling this to our attention. We have reformatted Figure 2 to ensure the arrows are aligned more precisely and the overall structure appears more professional. We believe this updated version addresses your concern while maintaining clarity and functionality.
Comment 6: Line 227, in chp.4, the authors discussed a variety of papers in this field, but most of the conclusive statement are qualitative, very little quantitative data results were presented. As known, 3DP is a precision manufacturing approach, I would expect the authors
discussed how this special character help the orthodontics field.
Response 6: Thank you for this valuable comment. We have incorporated more numerical data regarding advantages and disadvantages of the digital workflow into Chapter 2: Material and Methods, as we believe this is the most appropriate section to provide such technical details, alongside with the data extraction table of reviewed articles. This addition allows us to present quantitative results that highlight the precision and efficiency of 3D printing technology while maintaining clarity and focus in the discussion section. We hope this modification addresses your concern.
Comment 7: Line 423, chp. 4.2 discussed about the impact of AI on the 3DP orthodontics. I think this was a vital point as the rapid emerging of AI is sweeping almost everything..Nevertheless, it seems that only three papers were involved (i.e., [1,2,81])… all other papers of the 75 included had very little content relative to AI, please recheck the
database.
Response 7: Thank you for your comment. Upon rechecking the database, we found that 11 articles discussed the impact of AI on 3D-printed orthodontics, and they are cited in this chapter. We believe these articles cover various applications, including segmentation of tooth models, treatment planning, and workflow automation. Additionally, in Chapter 4.2 and 4.4, we have provided further suggestions on potential AI concerns and applications, such as utilizing AI for designing customized accessories and treatment planning to enhance the outcomes. We appreciate your feedback, which allowed us to clarify and expand on the role of AI in orthodontics within the manuscript.
Comment 8: Line 494, chp. 4.4 is a valuable chapter, nevertheless, readers would expect more creative points or/and insights from the authors rather than cited from published papers. In this chapter, in contrast, most statements were gained from papers of relevance (i.e., [24,97-102]..)
Response 8: Thank you for the comment. We appreciate that you value chapter 4.4. We also find it one of the most important chapters in the review. We managed to add more content, and we hope we have met your expectations.
Comment 9: Line 533, conclusion: “Direct printing introduces several advantages that can enhance both the effectiveness and efficiency of orthodontic treatment.” Please explain why 3DP can increase the efficiency of orthodontic treatment, in my own experiences, 3DP in fact
is not a technique in mature, and thereby the manufacturing process somehow took longer
than the traditional mold-assist process, and its effectiveness (I mean the 3DP) also subjected to the post-treatment. These all took additional time cost.
Response 9: Thank you for your insightful comment. We feel you have indeed raised a very good point, and your experience matches our experience. We agree that 3D printing (3DP) is a developing technology and we acknowledge its current limitations, such as extended manufacturing times, post-processing requirements, and the overall maturity of the process. These aspects, as you noted, can indeed offset its efficiency in comparison to traditional methods. To address your concern, we have revised the conclusion to clarify that the efficiency of 3DP lies in specific aspects of the workflow, such as improving precision, treatment predictability, and reducing chair-time for practices equipped with advanced tools. We also emphasized the importance of ongoing advancements, including AI automation, increased printing speed, and the potential of shape memory materials to address material barriers. These developments could address current inefficiencies and pave the way for broader adoption in the future. We hope these revisions adequately reflect your concerns and provide a balanced perspective on the current and future efficiency of 3DP in orthodontics. Thank you for raising this important point.
Comment 10: “Further research should focus on long-term biocompatibility, accompanied by clinical evaluations and case studies.” This was a true statement and indeed important, however, I did not see the authors explore the material development with respect to the orthodontics field. So where makes the author come across to this conclusion?
Response 10: Thank you for your comment and highlighitng this points. We agree with you that this is an imporant and true statement. While doing the literature review, we came across mutiple text citing the potential dangers in microplastics and chemicals from (3d printed) aligners. This process of reading through the literature led us to the conclusion, in agreement with you, that this is not just true, but also important. So, we thought this might be an important background information and would be of interest to our respected readers. However, we wanted to maintain the main focus of the article for the aims of readability and length without going into different directions, however important they might be. So, we aimed to strike a balance in mentioning it without derailing the focus of the article. We are considering exploring this topic in greater detail, as it deserves, in a full-length article. We feel that addressing the points you raised could significantly improve the quality of our manuscript. Thank you.
Let us thank you once again for helping us make our manuscript stronger. With all the added information, including figures and tables, we believe this scoping review is more detailed, comprehensive and well-structured than our previous version, and will be well-received by the readers.
Kind regards,
Authors
Reviewer 2 Report
Comments and Suggestions for Authors- Remove the parts that talks too much about aligners and retainers, like in lines 89–116, unless you want to compare them to auxiliary devices directly.
- Add more about "4D memory shape materials," for example how they could be used for making adaptive orthodontic devices that change with time during treatment.
- Give some detailed examples of how AI is helping in orthodontic work, like using it for separating tooth models from scans automatically.
- Include a part to talk about the problem of durability and storage for auxiliary devices, like how 3D-printed models can shrink over time, mentioned around lines 79–80.
- Make a table to compare studies, such as resin and metal devices, to show their differences in strength and results in real use.
- Explain the difficulties clinics face when using 3D printing, for example needing to train staff and buying expensive machines for post-processing.
- Talk about the safety risks from 3D printing, like the release of dangerous chemicals or small particles, and suggest how to protect against them.
- Add a simple flowchart to show the steps of making auxiliary devices with 3D printing, starting from imaging to the finished product.
- Write a few paragraphs about new ideas for auxiliary devices, like 3D-printed power arms or space maintainers, and how they help in treatments.
Author Response
Dear Reviewer 3,
Thank you very much for your insightful comments. Hereinbelow we address your concerns and suggestions one by one, and we hope we have met your expectations in doing so:
Comment 1: Remove the parts that talks too much about aligners and retainers, like in lines 89–116, unless you want to compare them to auxiliary devices directly.
Response 1: Thank you for the comment. We would like to clarify that the content refers exclusively to 4D aligners, with no mention of retainers. The focus on directly printed aligners was included to highlight their innovative nature and potential future applications, particularly in relation to auxiliary devices. In the discussion section we added more information on how the shape memory materials and directly printed aligners can actually incorporate auxiliaries within their structure, which makes them thus directly related to the scope of our review.
Comment 2: Add more about "4D memory shape materials," for example how they could be used for making adaptive orthodontic devices that change with time during treatment.
Response 2: Thank you for this valuable idea. We agree with you here too. In the discussion section, we added suggestion on how this technology could be beneficial in the future.
Comment 3: Give some detailed examples of how AI is helping in orthodontic work, like using it for separating tooth models from scans automatically.
Response 3: Thank you for your comment. While we have already discussed the use of AI for tasks like segmentation of tooth models in Chapter 4.2, we took your recommendation most seriously, so we detailed this aspect more. In response to your suggestion, we have expanded Chapter 4.4 to include additional potential applications of AI in orthodontics, such as automated treatment planning or designing of the appliance. These additions aim to provide a broader perspective on how AI can enhance various aspects of orthodontic workflows. We hope this addresses your comment.
Comment 4: Include a part to talk about the problem of durability and storage for auxiliary devices, like how 3D-printed models can shrink over time, mentioned around lines 79–80.
Response 4: Thank you for your comment. We searched for relevant articles in this research area. We tried to get to this point by mentioning the pioneering study of Knode et al. regarding future research directions when it comes to the shape preservation of 3D-printed models. In our clinical practice and in our experience, the big majority of 3d printed auxiliaries are individualised and manufactured shortly before the actual use. So, after being produced (whatever the fabrication technique is), they go directly or at least very shorty to the patient, for they can be highly individualized and thus are not meant for long-term storage for any patient that may come in the future. Part of the reason for that lies in the design process focusing on the actal situation, relative ease of production (compared for example to the manufacture by a major company) and the reasons regarding the storage you also mentioned.
Comment 5: Make a table to compare studies, such as resin and metal devices, to show their differences in strength and results in real use.
Response 5: Thank you for your suggestion. We think this is a great idea, which elevates the quality of our article meaningfully and happily implemented it. In the chapter 4.4. we have created a Figure titled "Comparison of 3D-Printed Resin, Metal, and Shape Memory Orthodontic Devices: Advantages, Disadvantages, and Future Potential" to address this comment. The table provides a comparison of resin and metal devices, highlighting their respective strengths and limitations based on clinical and manufacturing considerations. Additionally, we included a section on shape memory devices, which represent a promising innovation by potentially combining the advantages of both resin and metal devices. We believe this addition enriches the manuscript and aligns with your feedback.
Comment 6: Explain the difficulties clinics face when using 3D printing, for example needing to train staff and buying expensive machines for post-processing.
Response 6: Thank you for your comment. We think this is indeed very important and should be highlighted. We have expanded on these challenges in Chapter 4.4, detailing difficulties such as the need for staff training, the steep learning curve, and the significant financial investments required for purchasing and maintaining the printing and post-processing equipment. These additions aim to provide a more comprehensive discussion of the practical barriers clinics face when implementing the 3D printing technology. We appreciate your feedback and believe this enhancement addresses your concern.
Comment 7: Talk about the safety risks from 3D printing, like the release of dangerous chemicals or small particles, and suggest how to protect against them.
Response 7: Thank you for your comment. We feel this is a very important point you raised. In agreement with you we are also concerned about the safety risks, also in the perspective of using these. For this reason we have touched on the microplastics and chemical effects perspective. We have added a discussion on the safety risks associated with 3D printing, including the release of harmful chemicals and small particles. We also suggested protective measures, such as proper ventilation, the use of biocompatible materials, and adherence to safety protocols, to mitigate these risks.
Comment 8: Add a simple flowchart to show the steps of making auxiliary devices with 3D printing, starting from imaging to the finished product.
Response 8: Thank you for your suggestion. We have added a flowchart titled "Figure 2 – Simple scheme of manufacturing steps of customised 3D-printed orthodontic accessories" to illustrate the process of creating accessories devices using 3D printing. Please let us know if adding this scheme has addressed your comment.
Comment 9: Write a few paragraphs about new ideas for auxiliary devices, like 3D-printed power arms or space maintainers, and how they help in treatments.
Response 9: Thank you for your comment. We have already described 3D-printed power arms and space maintainers in detail in Chapters 4.1.1 and 4.1.2, highlighting their applications and benefits in orthodontic treatments. Additionally, in response to your suggestion, we have expanded Chapter 4.4 to include new ideas related to the use of shape memory materials in auxiliary devices. These materials hold great potential to enhance the functionality of orthodontic appliances by combining strength, adaptability, and aesthetic properties. We believe this addition addresses your request and enriches the manuscript. Please let us know if further modifications are needed.
Let us thank you once again for helping us make our manuscript stronger. With all the added information, including figures and tables, we believe this scoping review is more detailed, comprehensive and well-structured than our previous version, and will be well-received by the readers.
Kind regards,
Authors
