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Additional Editor Comments:

Dear authors

Thank you for submitting your manuscript to PLOS One journal.

The manuscript has been now reviewed by 2 independent reviewers who had some comments that should be addressed.

Kindly go through the comments and respond to all ccomments point by point.

We are looking forward to receiving the revised version.

Regards,

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

Reviewer #1: Partly

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously? -->?>

Reviewer #1: N/A

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available??>

The PLOS Data policy

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #1: Yes

Reviewer #2: Yes

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Reviewer #1: Thank you for giving me the chance to evaluate this work

Prevalence of Second Mesiobuccal Canal in Maxillary Molars of Iranian Population:Systematic Review with Meta-Analysis

Abstract

ok

Key words

better to be in alphabetical order

Introduction:

In general, not tight enough and need improvements, specially citing the recent and related references..

Better to go shortly highlighting what has been done in your population and how many studies and technique used in them.

then, the limitation present the current studies in your population, and clear the aim of the study

Missing the second mesiobuccal (MB2) canal was suggested as one of the most common failure

reasons for root canal treatment in maxillary molars (1).

The reference is not related at all, you should bring some reference from outcome studies or missed canals, or failure, Extra…..

Although most studies have shown the presence of the MB2 canal, there is no general agreement

about its prevalence in different populations (5).

Not related reference

Get one from gender differences, race differences and so on,

Better to get some systematic review studies reporting these variables.

The prevalence of MB2 in maxillary molars ranges from 10% to 95% (6),

This is a big statement, its better to mentions if is it worldwide or what exactly, also bring a new related reference, check Martins….

which might be related to the method of assessment and the race,

age, and gender of the study population (5).

Same note here the reference….

Materials and methods

ok

RESULTS:

In contrast, the lowest prevalence of MB2 canal was related to the direct

vision method with a prevalence of 27% (95%CI, 13_40; I2=0%), followed by the PA

radiography method with a prevalence of 15% (95%CI, -10_40; I2=91.17%)

SHOULD BE THE OTHER WAY AROUND

In contrast, the lowest prevalence was related to the direct vision method with a prevalence of 16% (95%CI, 4_27;I2=0%), followed by the PA radiography method with a prevalence of 4% (95% CI, -8_17;I2=40.52%)

SHOULD BE THE OTHER WAY AROUND

DISCUSSION:

Generally not bad but need to be improved,

Compare your pool outcome with other international studies and other sys reviews as well

You did good in explaining the variations between the pool of studies you collected

No limitations was mentioned in your study???

In the present study, the pooled prevalence of the MB2 canal in the maxillary first molar (60%)

was higher than the second molar (33%), which was similar to other studies (35).

poor reference, better to compare with other sys reviews worldwide, or mention more than one country to compare with…..

In various populations, a range of 25% to 93.5% and 34% to 50% have been reported for the first and second molars, respectively (S5 Table). This different range in the countries can be due to

various evaluation methods, racial groups, or geographical regions.

Where is the reference?

Most references in table S5 is old and well selected

Natural selection is also associated with phenotype changes (36). Large tooth size may be

maintained as a dominant natural selection (African population), while the reduction in tooth

size occurs in the absence of such force (37).

What do you mean by these sentences, better to clarify in the texts….

Further implication:

Future studies are suggested by accurately reporting the age, gender, and geographic location of the teeth, as well as using modern techniques, such as the microscope, loupe, and micro-CT.

CBCT IN VIVO IS THE BEST TO DESCRIBE ALL THE VARIABLES INCLUDING RIGHT AND LET, AGE, GENDER AND EXTEA…

Micro-CT is very precise but it can be traumatic and one of its imitation is the number of sample Versus CBCT Where you can get a very big sample

Conclusion:

The prevalence of the MB2 canal was higher in the first molar (60%) than in the second molar

(33%) of the maxilla, and the prevalence of the MB2 canal depended on the assessment method.

According to your study and limitations, the technique used is the main finding which make the result of the study not convincing compared to worldwide agreements of MB2

It can be improved and focused on the type of technique used

Reviewer #2: A good study has been done and most of the subjects that should be done in systematic review studies such as publication bias, risk of bias, heterogeneity, subgroup analysis, etc. have been done. But in order to increase the quality of the article, the following items are suggested to be reviewed and corrected:

1- PRISMA 2020 framework should be used in the study.

2- Due to the fact that the resolution of the graphs is low, it is suggested to save the images of the graphs with the tif extension.

3- It is better to perform sensitivity analysis for studies with a small sample size, such as Naseri's 2015 study (sample of 35 people). In such a way that these studies are removed and recalculate the pool effect.

4- The tool used to check the risk of bias seems to be the tool for evaluating the quality of studies, rather than risk. It is better to mention this and add the score of each study in table 1 and 2 (bibliographic table).

5- The bibliographic information table is incomplete; it is better to mention the type of study and the quality score of the study.

6- Several graphs and parameters have been used for some topics, such as heterogeneity. It is better to report only the Galbraith graph for this topic.

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Reviewer #1: No

Reviewer #2: No

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Prevalence of Second Mesiobuccal Canal in Maxillary Molars of Iranian Population: A Systematic Review with Meta-Analysis

PONE-D-24-24127R1

Dear Dr. Behdarvandi,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Mohmed Isaqali Karobari, BDS, MScD.Endo, Ph.D. Endo, FDS, FPFA, FICD, MFDS

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Dear Authors,

The authors have addressed all the comments and suggestions reviewers gave, and the manuscript has dramatically improved. In PRISMA, the reasons for excluding articles should be clearly stated, rather than saying reason 1, 2. The manuscript can be accepted for publication in its current form. I would like to congratulate the authors and wish them all the very best in their future endeavours.

Best regards and keep well.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions??>

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously? -->?>

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available??>

The PLOS Data policy

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English??>

Reviewer #2: Yes

**********

Reviewer #2: In PRISMA, the reasons for excluding articles should be clearly stated, rather than saying reason 1, 2.

**********

what does this mean? ). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy

Reviewer #2: Yes:  Dr Reza Goudarzi

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