One-Jaw versus Two-Jaw Orthognathic Surgery for Patients with Cleft: A Comparative Study Using 3D Imaging Virtual Surgical Planning

Round 1

Reviewer 1 Report

Review report

 

A brief summary

This article is about the original retrospective study of the anatomical characteristics of two simulated orthognathic surgeries (one-jaw and two-jaw) for patients with unilateral cleft lip and palate. The authors concluded that the two-jaw technique improves facial asymmetry and reduces the amount of maxillary advancement in LeFort I osteotomy. The results support the appropriateness of the choice of surgical plan for this patient group was appropriate. The reviewer would like the authors to add a note regarding the possible presence of patient selection bias and the limitations of this study design.

 

General concept comments

The concept of this research that hypothetically investigates what skeletal problems might arise when the one-jaw simulation is performed on a patient who had undergone two-jaw surgery is interesting. One of the results indicated in this article is that the asymmetry index improved with two-jaw planning more than with one-jaw planning. The reviewer also would like to know the comparison between one-jaw/ two-jaw planning and norms. In addition, the reviewer would like the authors to indicate if another method of statistical analysis might be preferable to the one used in this study. The reviewer hopes to contribute to the improvement of this article. Thank you.

 

Specific comments

Abstract

1. The two datasets (one-jaw/ two-jaw planning) are labeled as "groups", but if the authors performed two different simulations on the same subjects, would it be correct to describe them as “groups”? Please consider another naming. (p.1)

Materials and methods

2. Although not listed in the patient selection criteria, have any patients undergone maxillary or mandible alone orthognathic surgery during the same recruiting period? Due to the nature of this study, it is not surprising that one-jaw planning would have an unfavorable outcome since patients who received two-jaw surgery out of necessity were included in the study. But the authors mentioned that all patients with UCLP received two-jaw surgery in their institute in the discussion section. (p.2)
3. In the figure legend of Figure 1, the typo of “Tow-jaw surgical plan” was found. (p.4)
4. Could you please indicate which reference plane each X, Y, and Z corresponds to? (p.5)
5. The reviewer would like to know how many participants were included in the normative Taiwanese data analysis indicated in reference #17. Were they analyzed regardless of gender? (p.5)
6. The reviewer could not find any mention of Pearson’s correlation coefficient used for the assessment of intra-observer reproducibility in this section. A method used to evaluate the agreement between the two measurements is the Bland-Altman analysis. Please consider applying this method. (p.6)
7. The authors mentioned that “the T0, one-jaw, and two-jaw groups were compared with normative Taiwanese data using an independent t-test”. Which items were compared in this analysis? Distances or 3D cephalometric measurement parameters?
8. The authors mentioned that the correlation between one-jaw and two-jaw groups was calculated using the Spearman correlation coefficient. Which kind of item was compared in this method and where were the results indicated? I could not find the Spearman correlation in the results section. In addition, why did the authors consider using Spearman instead of Pearson?

 

Results

9. In Table 2, the “Mean differences” were shown. Did it mean “Distances”? Although the reviewer thinks that ANS can be moved by surgical simulations, ANS in one-jaw and two jaw groups were not shown. The lines between each landmark were not necessary, I think.
10. The phrase “3. D cephalometric measurements” might be a typo of “3D cephalometric measurements”. (p.7)
11. In the Table. 3, the row of SNB is written in bold and the line under this raw would not be necessary. (p.7)
12. Is “the posterior dental cant” means “the mean posterior dental cant”? The standard deviation of 0.89 seems to be relatively large. (p.8)
13. In Table 4, the Pog-N perpendicular was compared between one-jaw and two-jaw groups. But Pog could be moved in two-jaw simulation because the authors performed genioplasty for 31 patients in this study. The comparisons with norms were not indicated.
14. The ANS was not compared in Table 4.
15. Asymmetry Index of T0, one-jaw, and two-jaw groups were compared with a t-test. Is it not necessary to conduct ANOVA and post-hoc tests? Does this cause multiple comparison problems?
16. The reviewer thinks that Pogonion and Menton should not be included if the two-jaw planning includes genioplasty. Could you please indicate the authors’ opinion?
17. Figure. 2 shows the same results as Table. 6 and does not include the error bars. (p.10)

 

Discussion

18. The planning methods were written as 1-jaw and 2-jaw in this section. Please unify the description with other sections (same for Table 4—6 and Figure 2).
19. Is the word “sleep” on page 15 a typo of “sleep apnea”?

Comments for author File: Comments.docx

Author Response

Dear Sirs,

 

Thank you for the comments as the comments help to improve the manuscript. We have tried to revise the manuscript according to the comment. The responses are as follows.

 

Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Is the research design appropriate?	(x)	( )	( )	( )
Are the methods adequately described?	( )	( )	(x)	( )
Are the results clearly presented?	( )	( )	(x)	( )
Are the conclusions supported by the results?	( )	(x)	( )	( )

Comments and Suggestions for Authors

 

Responses:

English language spelling and style were checked. The methods, results, and conclusions were revised as suggestion and shown in the following responses and in the revised manuscript.

 

Review report

 A brief summary

This article is about the original retrospective study of the anatomical characteristics of two simulated orthognathic surgeries (one-jaw and two-jaw) for patients with unilateral cleft lip and palate. The authors concluded that the two-jaw technique improves facial asymmetry and reduces the amount of maxillary advancement in LeFort I osteotomy. The results support the appropriateness of the choice of surgical plan for this patient group was appropriate. The reviewer would like the authors to add a note regarding the possible presence of patient selection bias and the limitations of this study design.

 

Response

Thank you for the comments. Response to the patient selection were shown in the following.

 

General concept comments

The concept of this research that hypothetically investigates what skeletal problems might arise when the one-jaw simulation is performed on a patient who had undergone two-jaw surgery is interesting. One of the results indicated in this article is that the asymmetry index improved with two-jaw planning more than with one-jaw planning. The reviewer also would like to know the comparison between one-jaw/ two-jaw planning and norms. In addition, the reviewer would like the authors to indicate if another method of statistical analysis might be preferable to the one used in this study. The reviewer hopes to contribute to the improvement of this article. Thank you.

 

Response

Thank you for the comments. The responses were shown in the following.

 

Specific comments

Abstract

1. The two datasets (one-jaw/ two-jaw planning) are labeled as "groups", but if the authors performed two different simulations on the same subjects, would it be correct to describe them as “groups”? Please consider another naming. (p.1)

Response:

The simulations were performed on the same group of patients. The labeled “group” of one-jaw/ two-jaw planning was renamed as “design”.

Materials and methods

1. Although not listed in the patient selection criteria, have any patients undergone maxillary or mandible alone orthognathic surgery during the same recruiting period? Due to the nature of this study, it is not surprising that one-jaw planning would have an unfavorable outcome since patients who received two-jaw surgery out of necessity were included in the study. But the authors mentioned that all patients with UCLP received two-jaw surgery in their institute in the discussion section. (p.2)

Response

More than 98% of patients with cleft received two-jaw orthognathic surgery when it was indicated. This paradigm shift was mentioned in our previous publications, with the reasons more than facial symmetry, but also including other facial aesthetic purposes, such as smile arc. It is the center’s treatment preference, and indeed could be a bias. All UCLP patients received two-jaw during the study period. The statements were made in the revised manuscript.

1. In the figure legend of Figure 1, the typo of “Tow-jaw surgical plan” was found. (p.4)

Response:

The figure legend of Figure 1 has been revised to Two-jaw surgical plan.

1. Could you please indicate which reference plane each X, Y, and Z corresponds to?

Response:

The definition of the X, Y, and Z axis have been added to Table 1. Three coordinates (X, Y, Z), which represent the transverse, anteroposterior, and vertical positions, respectively.

1. The reviewer would like to know how many participants were included in the normative Taiwanese data analysis indicated in reference #17. Were they analyzed regardless of gender? (p.5)

Response:

A cross-sectional study in reference #17 was conducted on 30 male and 30 female adults were included in the normative Taiwanese data analysis. Descriptive statistics for some 3D cephalometric measurements in Table 3. All p-value of these 3D cephalometric measurements between male and female were higher than 0.05 among that were not statistically significant among gender. Therefore they are grouped together for comparisons.

1. The reviewer could not find any mention of Pearson’s correlation coefficient used for the assessment of intra-observer reproducibility in this section. A method used to evaluate the agreement between the two measurements is the Bland-Altman analysis. Please consider applying this method. (p.6)

Response:

Thank you for the comment. We removed the Pearson’s method, and performed the Bland-Altman analysis. The results were shown in the revised manuscript. All figure and table numberings were accordingly changed.

1. The authors mentioned that “the T0, one-jaw, and two-jaw groups were compared with normative Taiwanese data using an independent t-test”. Which items were compared in this analysis? Distances or 3D cephalometric measurement parameters?

Response:

This paragraph was rewritten as follows. The T0 was compared with normative Taiwanese data using independent t-test. Spearman correlation coefficient was first used to calculate the correlation between one-jaw and two-jaw designs. The p value less than 0.05 indicated that the correlation between two groups was high. Then the paired or independent t-test was accordingly selected to examine the differences of 3D cephalometric measurements and ASI between the one-jaw and two-jaw designs.

1. The authors mentioned that the correlation between one-jaw and two-jaw groups was calculated using the Spearman correlation coefficient. Which kind of item was compared in this method and where were the results indicated? I could not find the Spearman correlation in the results section. In addition, why did the authors consider using Spearman instead of Pearson?

Response:

The Spearman rank correlation coefficient (Spearman ρ) is a nonparametric measurement correlation. It was used to determine the relation existing between one-jaw and two-jaw of data. The parameters shown as Table 3-5 then were decided to use paired-t or independent t test to compare the difference between two sets.

 Results

1. In Table 2, the “Mean differences” were shown. Did it mean “Distances”? Although the reviewer thinks that ANS can be moved by surgical simulations, ANS in one-jaw and two jaw groups were not shown. The lines between each landmark were not necessary, I think.

Response:

From a previous comment, we removed the Pearson’s test and performed Bland-Altman analysis. Therefore, table 2 was deleted.

1. The phrase “3. D cephalometric measurements” might be a typo of “3D cephalometric measurements”. (p.7)

Response:

Thank you for the correction. We do not find this problem in the submitted paper. Maybe it is an issue of software.

1. In the Table. 3, the row of SNB is written in bold and the line under this raw would not be necessary. (p.7)

Response:

Thank you for the correction. We do not find this problem in the submitted paper. Maybe it is an issue of software.

1. Is “the posterior dental cant” means “the mean posterior dental cant”? The standard deviation of 0.89 seems to be relatively large. (p.8)

Response:

Yes, “the posterior dental cant” indicated “the mean posterior dental cant”. In clinical practice, we try to level the posterior dental cant but do not intend to make it 0 degree, and rather coordinate with other parameters for symmetric and harmonious positioning of the maxillomandibular complex. The posterior dental cant revealed in the range of -0.88 to 2.68, matching our clinical purpose. We have incorporated this statement in the discussion.

1. In Table 4, the Pog-N perpendicular was compared between one-jaw and two-jaw groups. But Pog could be moved in two-jaw simulation because the authors performed genioplasty for 31 patients in this study. The comparisons with norms were not indicated.

Response:

Thank you for the comment. The Table 4 was renamed as Table 3. Pog was marked in the same definition with or without genioplasty. The norms were indicated in Table 2 for reference. We did perform statistical comparisons between the one-jaw and norms as well as two-jaw and norms, but decided not to include the data in the manuscript in order to simplify the main theme of the study, i.e., one-jaw versus two-jaw. However, the differences between the one-jaw or two-jaw and norms were evident by looking at the data in Table 2 and 3 by the readers. Comments on the differences were also made in the manuscript.

1. The ANS was not compared in Table 4.

Response:

Thank you for the comment. The Table 4 was renamed as Table 3. The ANS was deviated from midsagittal line from birth to maturity in patients with unilateral cleft lip and palate. The deviation was shown in Table 2. The ANS was also frequently burred during orthognathic surgery in our practice. Therefore, we did not use ANS as a midline landmark in the simulation as well as assessment.

1. Asymmetry Index of T0, one-jaw, and two-jaw groups were compared with a t-test. Is it not necessary to conduct ANOVA and post-hoc tests? Does this cause multiple comparison problems?

Response

Thank you for the comment. As stated by the reviewer, this approach will cause multiple comparison problems. The ANOVA and post-hoc tests were applied to multiple experimental groups and one or more control groups, although T0 was the control group and one-jaw and two-jaw design were experimental groups. We understand the issues. Because the main purpose of this study was to compare the difference of asymmetry index between one-jaw and two-jaw design using 3-dimensional imaging surgical simulation. The paired and independent t-test were used for individual comparisons.

1. The reviewer thinks that Pogonion and Menton should not be included if the two-jaw planning includes genioplasty. Could you please indicate the authors’ opinion?

Response:

Thank you for the comment. In our 3D simulation, we hope to align the midline landmarks in order to achieve possibly ideal symmetry and facial appearance. The facial midline landmarks included A, B, U1, L1, Pog and Me in this study and in our routine planning. Inclusion of Pog and Me in this study served to illustrate the difference between the one-jaw and two-jaw designs.

1. Figure. 2 shows the same results as Table. 6 and does not include the error bars. (p.10)

Response:

Thank you for the comment. We agree that Figure 2 was redundant. Figure 2 was removed. Other Figures were re-numbered accordingly.

Discussion

1. The planning methods were written as 1-jaw and 2-jaw in this section. Please unify the description with other sections (same for Table 4—6 and Figure 2).

Response:

The description of 1-jaw and 2-jaw was unified in the revised manuscript. Thank you.

1. Is the word “sleep” on page 15 a typo of “sleep apnea”?

Response:

The word “sleep” has been revised to “sleep apnea”. Thank you.

peer-review-18745933.v1.docx

 

 

 

 

 

Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
( ) English language and style are fine/minor spell check required
(x) I don't feel qualified to judge about the English language and style

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Is the research design appropriate?	( )	( )	(x)	( )
Are the methods adequately described?	(x)	( )	( )	( )
Are the results clearly presented?	(x)	( )	( )	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

Comments and Suggestions for Authors

This article aims to compare the orthognathic planning of cleft patients for one jaw or two jaw surgery to find if it is feasible to do one jaw surgery for these patients by using computer assisted design, planning and evaluation. All the included patients had already underwent bimaxillary surgery. This retrospective study finds that there is a significant improvement of the esthetic and functional outcome for cleft patients when treating them with two-jaw surgery when comparing with one-jaw surgery.

The methodology is very well conceived. The fact that the authors excluded patients with segmental and subapical osteotomies is very good for the aims of the study. There is an important aspect when treating cleft patients and I believe that most of them need maxillary expansion, some surgical some orthodontic, others both. I would like to ask the authors to add the missing data for included patients in the study underwent previous maxillary expansions and in which way.

 Response:

Thank you for the comment. In our practice in the craniofacial center, Chang Gung Memorial Hospital, most patients with cleft mainly had anterior-posterior discrepancy between the jaws rather than the arch or width discrepancy. The arch coordination could mostly be achieved by moving the maxilla forward and mandible backward. Reasons for the adequate maxillary arch development was partly due to the use of buccal fat pad covering the lateral raw surface during primary palate repair (This finding will be published in Plastic & Reconstructive Surgery in August issue, 2022). We did not perform maxillary expansion before the orthognathic surgery. We preferred to do minimal or minor presurgical orthodontic treatment, i.e., modified surgery-first approach). Maxillary expansion, if required, will be performed after the orthognathic surgery by orthodontic methods. Many times, the expansion was required in the cleft-side canine area, rather than the molar area. Some statements were added in the Methods.

In the discussion paragraph there is a point to be made with the discrepancies that remain after the one-jaw surgery. There is the possibility of orthodontic correction with temporary anchorage devices which can correct the occlusal cantus and midline discrepancies for the unoperated maxilla. I believe that with the right collaboration some of the cases which are two-jaw surgery at the first glance can be resolved with only one-jaw surgery if TADs are placed. The occlusal place can also be adjusted by maxillary molar intrusion.

Response:

Thank you for the comment. The points are well taken. We believe that one-jaw surgery with orthodontic treatment and TADs could also solve the problems for patients with cleft. As we mentioned in the manuscript, one-jaw approach is still a popular method, and two-jaw approach is favored in our center. The surgeons and centers should choose the method based on patient’s condition and team’s preference. We have added the statements in the Discussion.

The manuscript is well written and well structured. The references are appropriate for the text.

 Response:

Thank you for the comment.

Author Response File: Author Response.docx

Reviewer 2 Report

This article aims to compare the orthognathic planning of cleft patients for one jaw or two jaw surgery to find if it is feasible to do one jaw surgery for these patients by using computer assisted design, planning and evaluation. All the included patients had already underwent bimaxillary surgery. This retrospective study finds that there is a significant improvement of the esthetic and functional outcome for cleft patients when treating them with two-jaw surgery when comparing with one-jaw surgery.

The methodology is very well conceived. The fact that the authors excluded patients with segmental and subapical osteotomies is very good for the aims of the study. There is an important aspect when treating cleft patients and I believe that most of them need maxillary expansion, some surgical some orthodontic, others both. I would like to ask the authors to add the missing data for included patients in the study underwent previous maxillary expansions and in which way.

 

In the discussion paragraph there is a point to be made with the discrepancies that remain after the one-jaw surgery. There is the possibility of orthodontic correction with temporary anchorage devices which can correct the occlusal cantus and midline discrepancies for the unoperated maxilla. I believe that with the right collaboration some of the cases which are two-jaw surgery at the first glance can be resolved with only one-jaw surgery if TADs are placed. The occlusal place can also be adjusted by maxillary molar intrusion.

The manuscript is well written and well structured. The references are appropriate for the text.

 

Author Response

Dear Sirs,

 

Thank you for the comments as the comments help to improve the manuscript. We have tried to revise the manuscript according to the comment. The responses are as follows.

 

Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
(x) English language and style are fine/minor spell check required
( ) I don't feel qualified to judge about the English language and style

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Is the research design appropriate?	(x)	( )	( )	( )
Are the methods adequately described?	( )	( )	(x)	( )
Are the results clearly presented?	( )	( )	(x)	( )
Are the conclusions supported by the results?	( )	(x)	( )	( )

Comments and Suggestions for Authors

 

Responses:

English language spelling and style were checked. The methods, results, and conclusions were revised as suggestion and shown in the following responses and in the revised manuscript.

 

Review report

 A brief summary

This article is about the original retrospective study of the anatomical characteristics of two simulated orthognathic surgeries (one-jaw and two-jaw) for patients with unilateral cleft lip and palate. The authors concluded that the two-jaw technique improves facial asymmetry and reduces the amount of maxillary advancement in LeFort I osteotomy. The results support the appropriateness of the choice of surgical plan for this patient group was appropriate. The reviewer would like the authors to add a note regarding the possible presence of patient selection bias and the limitations of this study design.

 

Response

Thank you for the comments. Response to the patient selection were shown in the following.

 

General concept comments

The concept of this research that hypothetically investigates what skeletal problems might arise when the one-jaw simulation is performed on a patient who had undergone two-jaw surgery is interesting. One of the results indicated in this article is that the asymmetry index improved with two-jaw planning more than with one-jaw planning. The reviewer also would like to know the comparison between one-jaw/ two-jaw planning and norms. In addition, the reviewer would like the authors to indicate if another method of statistical analysis might be preferable to the one used in this study. The reviewer hopes to contribute to the improvement of this article. Thank you.

 

Response

Thank you for the comments. The responses were shown in the following.

 

Specific comments

Abstract

1. The two datasets (one-jaw/ two-jaw planning) are labeled as "groups", but if the authors performed two different simulations on the same subjects, would it be correct to describe them as “groups”? Please consider another naming. (p.1)

Response:

The simulations were performed on the same group of patients. The labeled “group” of one-jaw/ two-jaw planning was renamed as “design”.

Materials and methods

1. Although not listed in the patient selection criteria, have any patients undergone maxillary or mandible alone orthognathic surgery during the same recruiting period? Due to the nature of this study, it is not surprising that one-jaw planning would have an unfavorable outcome since patients who received two-jaw surgery out of necessity were included in the study. But the authors mentioned that all patients with UCLP received two-jaw surgery in their institute in the discussion section. (p.2)

Response

More than 98% of patients with cleft received two-jaw orthognathic surgery when it was indicated. This paradigm shift was mentioned in our previous publications, with the reasons more than facial symmetry, but also including other facial aesthetic purposes, such as smile arc. It is the center’s treatment preference, and indeed could be a bias. All UCLP patients received two-jaw during the study period. The statements were made in the revised manuscript.

1. In the figure legend of Figure 1, the typo of “Tow-jaw surgical plan” was found. (p.4)

Response:

The figure legend of Figure 1 has been revised to Two-jaw surgical plan.

1. Could you please indicate which reference plane each X, Y, and Z corresponds to?

Response:

The definition of the X, Y, and Z axis have been added to Table 1. Three coordinates (X, Y, Z), which represent the transverse, anteroposterior, and vertical positions, respectively.

1. The reviewer would like to know how many participants were included in the normative Taiwanese data analysis indicated in reference #17. Were they analyzed regardless of gender? (p.5)

Response:

A cross-sectional study in reference #17 was conducted on 30 male and 30 female adults were included in the normative Taiwanese data analysis. Descriptive statistics for some 3D cephalometric measurements in Table 3. All p-value of these 3D cephalometric measurements between male and female were higher than 0.05 among that were not statistically significant among gender. Therefore they are grouped together for comparisons.

1. The reviewer could not find any mention of Pearson’s correlation coefficient used for the assessment of intra-observer reproducibility in this section. A method used to evaluate the agreement between the two measurements is the Bland-Altman analysis. Please consider applying this method. (p.6)

Response:

Thank you for the comment. We removed the Pearson’s method, and performed the Bland-Altman analysis. The results were shown in the revised manuscript. All figure and table numberings were accordingly changed.

1. The authors mentioned that “the T0, one-jaw, and two-jaw groups were compared with normative Taiwanese data using an independent t-test”. Which items were compared in this analysis? Distances or 3D cephalometric measurement parameters?

Response:

This paragraph was rewritten as follows. The T0 was compared with normative Taiwanese data using independent t-test. Spearman correlation coefficient was first used to calculate the correlation between one-jaw and two-jaw designs. The p value less than 0.05 indicated that the correlation between two groups was high. Then the paired or independent t-test was accordingly selected to examine the differences of 3D cephalometric measurements and ASI between the one-jaw and two-jaw designs.

1. The authors mentioned that the correlation between one-jaw and two-jaw groups was calculated using the Spearman correlation coefficient. Which kind of item was compared in this method and where were the results indicated? I could not find the Spearman correlation in the results section. In addition, why did the authors consider using Spearman instead of Pearson?

Response:

The Spearman rank correlation coefficient (Spearman ρ) is a nonparametric measurement correlation. It was used to determine the relation existing between one-jaw and two-jaw of data. The parameters shown as Table 3-5 then were decided to use paired-t or independent t test to compare the difference between two sets.

 Results

1. In Table 2, the “Mean differences” were shown. Did it mean “Distances”? Although the reviewer thinks that ANS can be moved by surgical simulations, ANS in one-jaw and two jaw groups were not shown. The lines between each landmark were not necessary, I think.

Response:

From a previous comment, we removed the Pearson’s test and performed Bland-Altman analysis. Therefore, table 2 was deleted.

1. The phrase “3. D cephalometric measurements” might be a typo of “3D cephalometric measurements”. (p.7)

Response:

Thank you for the correction. We do not find this problem in the submitted paper. Maybe it is an issue of software.

1. In the Table. 3, the row of SNB is written in bold and the line under this raw would not be necessary. (p.7)

Response:

Thank you for the correction. We do not find this problem in the submitted paper. Maybe it is an issue of software.

1. Is “the posterior dental cant” means “the mean posterior dental cant”? The standard deviation of 0.89 seems to be relatively large. (p.8)

Response:

Yes, “the posterior dental cant” indicated “the mean posterior dental cant”. In clinical practice, we try to level the posterior dental cant but do not intend to make it 0 degree, and rather coordinate with other parameters for symmetric and harmonious positioning of the maxillomandibular complex. The posterior dental cant revealed in the range of -0.88 to 2.68, matching our clinical purpose. We have incorporated this statement in the discussion.

1. In Table 4, the Pog-N perpendicular was compared between one-jaw and two-jaw groups. But Pog could be moved in two-jaw simulation because the authors performed genioplasty for 31 patients in this study. The comparisons with norms were not indicated.

Response:

Thank you for the comment. The Table 4 was renamed as Table 3. Pog was marked in the same definition with or without genioplasty. The norms were indicated in Table 2 for reference. We did perform statistical comparisons between the one-jaw and norms as well as two-jaw and norms, but decided not to include the data in the manuscript in order to simplify the main theme of the study, i.e., one-jaw versus two-jaw. However, the differences between the one-jaw or two-jaw and norms were evident by looking at the data in Table 2 and 3 by the readers. Comments on the differences were also made in the manuscript.

1. The ANS was not compared in Table 4.

Response:

Thank you for the comment. The Table 4 was renamed as Table 3. The ANS was deviated from midsagittal line from birth to maturity in patients with unilateral cleft lip and palate. The deviation was shown in Table 2. The ANS was also frequently burred during orthognathic surgery in our practice. Therefore, we did not use ANS as a midline landmark in the simulation as well as assessment.

1. Asymmetry Index of T0, one-jaw, and two-jaw groups were compared with a t-test. Is it not necessary to conduct ANOVA and post-hoc tests? Does this cause multiple comparison problems?

Response

Thank you for the comment. As stated by the reviewer, this approach will cause multiple comparison problems. The ANOVA and post-hoc tests were applied to multiple experimental groups and one or more control groups, although T0 was the control group and one-jaw and two-jaw design were experimental groups. We understand the issues. Because the main purpose of this study was to compare the difference of asymmetry index between one-jaw and two-jaw design using 3-dimensional imaging surgical simulation. The paired and independent t-test were used for individual comparisons.

1. The reviewer thinks that Pogonion and Menton should not be included if the two-jaw planning includes genioplasty. Could you please indicate the authors’ opinion?

Response:

Thank you for the comment. In our 3D simulation, we hope to align the midline landmarks in order to achieve possibly ideal symmetry and facial appearance. The facial midline landmarks included A, B, U1, L1, Pog and Me in this study and in our routine planning. Inclusion of Pog and Me in this study served to illustrate the difference between the one-jaw and two-jaw designs.

1. Figure. 2 shows the same results as Table. 6 and does not include the error bars. (p.10)

Response:

Thank you for the comment. We agree that Figure 2 was redundant. Figure 2 was removed. Other Figures were re-numbered accordingly.

Discussion

1. The planning methods were written as 1-jaw and 2-jaw in this section. Please unify the description with other sections (same for Table 4—6 and Figure 2).

Response:

The description of 1-jaw and 2-jaw was unified in the revised manuscript. Thank you.

1. Is the word “sleep” on page 15 a typo of “sleep apnea”?

Response:

The word “sleep” has been revised to “sleep apnea”. Thank you.

peer-review-18745933.v1.docx

 

 

 

 

 

Open Review

(x) I would not like to sign my review report
( ) I would like to sign my review report

English language and style

( ) Extensive editing of English language and style required
( ) Moderate English changes required
( ) English language and style are fine/minor spell check required
(x) I don't feel qualified to judge about the English language and style

 

	Yes	Can be improved	Must be improved	Not applicable
Does the introduction provide sufficient background and include all relevant references?	(x)	( )	( )	( )
Is the research design appropriate?	( )	( )	(x)	( )
Are the methods adequately described?	(x)	( )	( )	( )
Are the results clearly presented?	(x)	( )	( )	( )
Are the conclusions supported by the results?	(x)	( )	( )	( )

Comments and Suggestions for Authors

This article aims to compare the orthognathic planning of cleft patients for one jaw or two jaw surgery to find if it is feasible to do one jaw surgery for these patients by using computer assisted design, planning and evaluation. All the included patients had already underwent bimaxillary surgery. This retrospective study finds that there is a significant improvement of the esthetic and functional outcome for cleft patients when treating them with two-jaw surgery when comparing with one-jaw surgery.

The methodology is very well conceived. The fact that the authors excluded patients with segmental and subapical osteotomies is very good for the aims of the study. There is an important aspect when treating cleft patients and I believe that most of them need maxillary expansion, some surgical some orthodontic, others both. I would like to ask the authors to add the missing data for included patients in the study underwent previous maxillary expansions and in which way.

 Response:

Thank you for the comment. In our practice in the craniofacial center, Chang Gung Memorial Hospital, most patients with cleft mainly had anterior-posterior discrepancy between the jaws rather than the arch or width discrepancy. The arch coordination could mostly be achieved by moving the maxilla forward and mandible backward. Reasons for the adequate maxillary arch development was partly due to the use of buccal fat pad covering the lateral raw surface during primary palate repair (This finding will be published in Plastic & Reconstructive Surgery in August issue, 2022). We did not perform maxillary expansion before the orthognathic surgery. We preferred to do minimal or minor presurgical orthodontic treatment, i.e., modified surgery-first approach). Maxillary expansion, if required, will be performed after the orthognathic surgery by orthodontic methods. Many times, the expansion was required in the cleft-side canine area, rather than the molar area. Some statements were added in the Methods.

In the discussion paragraph there is a point to be made with the discrepancies that remain after the one-jaw surgery. There is the possibility of orthodontic correction with temporary anchorage devices which can correct the occlusal cantus and midline discrepancies for the unoperated maxilla. I believe that with the right collaboration some of the cases which are two-jaw surgery at the first glance can be resolved with only one-jaw surgery if TADs are placed. The occlusal place can also be adjusted by maxillary molar intrusion.

Response:

Thank you for the comment. The points are well taken. We believe that one-jaw surgery with orthodontic treatment and TADs could also solve the problems for patients with cleft. As we mentioned in the manuscript, one-jaw approach is still a popular method, and two-jaw approach is favored in our center. The surgeons and centers should choose the method based on patient’s condition and team’s preference. We have added the statements in the Discussion.

The manuscript is well written and well structured. The references are appropriate for the text.

 Response:

Thank you for the comment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

We would like to thank the authors for the modifications and the response. We would like to also to see the further research regarding the maxillary transverse dimension and the fat pad surgical technique which in publishing.