I appreciate the letter presented by Costa et al.¹ regarding the recently published review article².

First of all, as stated in “9.1.3 Why perform a meta-analysis in a review?” of “Cochrane Handbook for Systematic Reviews of Interventions”³, presence of more than author is optional to decrease selection bias not an obligatory to accept or refuse the review because it is very common to let third one to remove the conflict or use other statistical means to accept or reject the paper that I think that the reviewer of the article proficiently can play that role.

Also, Fig. 1 is an image from “page 88” of the review² and you notice the systematic PICO very clear in subtitles.

Finally, divide the follow-up period according to the heterogeneity between studies. When heterogeneity found you should divide into subgroups as short period-intermediate period and long period follow up and we all know that splint wearing period affect muscles and habits so we should differentiate the results according to the period of wearing I think no problem in that division specially the results becomes more clear.

Thank you for refer.

Thank you for your effort.

Any further announcement is welcomed.