The authors discuss their retrospective findings regarding factors influencing the onsent of Oral Mucositis in a cohort of pediatric patients receiving hematopoietic stem cell transplantation. The article is interesting and deals with relevant issues that can influence everyday clinical practice so I believe it is worth giving them the possibility of publishing their results following some revisions.

ABSTRACT
Page 2 Line 7-8: This study aimed at determining (instead of to determine)
Page 2 Line 44: Multivariable logistic regression confirmed that the risk ok OM is lower in pediatric patients… (instead of decreases)
Page 3 Line 10: This study identified a significant correlation between the decreased prevalence of OM and patients with cancer. This sentence is not clear. I would substitute it with: “This study identified a significant lower prevalence of OM in patients with cancer if compared to other conditions.”

INTRODUCTION
Page 3 Line 27: Mucositis, or mucosal barrier injury, is a supportive care condition (change to “is a condition needing supportive care”) characterized by inflammation, erosion, …

I think it is mandatory to cite Professor Sonis when giving a definition of OM.

Page 4 Line 19: The considerable complications: please change to “the most invalidating” and eliminate “mostly”
Page 4 Line 27: However, there is little known on (change to “little is known about”) the relevant factors associated with increased susceptibility of individuals to profound (“change to “severe”)OM…
Page 4 Line 40: Pathogenesis of OM revealed a five-episode complex biological process (please change to “Pathogenesis of OM is characterized by a complex five step biological process”)
Again I would suggest citing Professor Sonis.

Page 5 Line 11: Eliminate “for the time being”
Page 5 Line 17: substitute “so as” with “in order”
Page 5 Line 24: change “to determin and to identify with “at determining and At identifying respectively

ETHICAL APPROVAL
It is fundamental to indicate the data regarding ethical approval from author’s board. In the paperi t is indicated with “XXX”, maybe an error…

STUDY DESIGN AND SETTING
Also here the name of the department is incomplete and indicated with XXX…please complete it.
INCLUSION AND EXCLUSION CRITERIA
Where patients hospitalized during your evaluation? Was any of the patients under parenteral nutrition? Where only patients that followed the oral hygiene/therapeutical protocol included (Mentioned in the discussion)?

STATISTICAL ANALYSIS
Page 7 line 48: eliminate “simple”

SAMPLE SIZE
If you state that 143 was the minimum number of eligible patients that ensure statistical significance, why did you include only 140 subjects?

RESULTS
Page 10 line 10: these sentences are confusing (from “results indicated that higher number…” to the end”) and seem in contrast. Plus the number of autologous HSCT is very low, especially if compared to that af allogenic HSCT. I am not sure that the statistics well explained if this difference in number of cases is significant or not, please clarify.

Page 10 Line 46: were significantly associated with the reduction of OM, please change to “had significantly lower OM”.
Page 10 Line 50: please clarify the sentence regarding younger patients, did you mean they developed less and less severe OM?

Page 11 line 1…: It is not very clear how the comparison between weeks is inserted in the regression.
Please create an explanatory table also for the multiple regression.

DISCUSSION
Page 11 Line 44: please change: aimed at determining and at identifying
Page 12 Line 24: Consequently, the aforementioned challenges are likely to lead to missing data, though it is a well-recognized complication and has been proposed in several studies: This sentence is not clear, please clarify.

“Besides, the prevention protocols that were implemented at the study center, such as a supersaturated calcium phosphate rinse and the use of an extra-soft toothbrush twice a day with the existing oral hygiene protocol regimen (0.2% chlorhexidine gluconate + 3% sodium bicarbonate + nystatin 100000 U/ml). Both preventive protocols were found to be effective in the reduction of OM occurrence “ This sentence is incomplete. Do you mean that you usually apply this protocol to pediatrics undergoing HSCT so you assume that all the included patients performed this protocol? Did you compare your results with those of the cited authors?If so I believe it would be interesting to insert this protocol in the methods and to clarify if you believe this may have influeced the onset of OM.

Page 12 Line 49: change “in keeping” to “in accordance”, Change “difference” to “differences”
Page 13 Line 6: These findings are in accord (change to Accordance) with those previously obtained in children, both of whom received (change to “with those of previous studies obtained in children who received…)

Page 13 Line 36: rather than the disease change to “rather than to the disease”
Page 13 Line 51: More related change to “more likely”

CONCLUSION
Page 14 Line 35: Change “regiment” to “regimen”.

Table 1: specify gender and age for each diagnosis.
Table 2: is the WBC count identically distributed in each type of diagnosis? It would be interesting to differentiate it accordign to diagnosis
Table 4: it is not very clear how to read the table. What does the chi squared test refer to? It is formed of 4 variables whereas in the way you present the table it seem to refer to six data. Otherwise you should have a Chi square test for each couple of data (cancer 1 week, HMD 1 week and so on)

In my opinion, the discussiom of the results could be incremented. For example, the author should state which clinical implication their research should have in the everyday clinical practice They mentioned an oral protocol, do they think it is worth giving it to all patients? Would you differentiate strategies in older non cancer patients?

Dear authors,
Thank you for addressing all the points I have mentioned in my previous revision.
Although there are a lot of tables, the results are well described and guide the reading of the data. The limitation section and the implementation of the discussion give completeness and raise important issues for future research. The clinical implication of you work is now clear and will certainly be a starting point for improving patients care. I believe your manuscript is now ready to be published in OD, prior some minor grammar and spelling corrections.