The aim of the study is clear. The abstract explained briefly what was concluded and also the methodology. The title of the article is appropriately selected and denotes the study performed although more work was done.

The references are recent (2019) and relevant in addition to this are well written and arranged and highly related to the study. The authors clearly explained what is said about the Piezocision Corticotomy and how it affects the speed and enhancement of orthodontic tooth movement. The research question was obvious in their randomized clinical trial in which they tried to differentiate between the en masse retraction with and without the Piezocision Corticotomy. Their investigation was justified as regards that the en masse retraction and orthodontic treatment in general combined with the Piezocision Corticotomy is relatively new. The process of subject selection was clear.

The authors used a randomized, controlled clinical trial included comprised two groups treated with premolars extraction: in which one group treatment comprised corticotomy while the other without. The question arise here, why the authors assessed the pain level as long as they prescribed paracetamol as a pain killer.

Data presented in the tables and figures are all relevant and clear. The unites and figures are appropriate and the tables are well arranged and clear. The results text is enough and it is good although there is some text repetition of the data presented in the tables and figures. The statistics presented in a good way and clearly done. The discussion section is well written and the study results obtained are elaborated clearly with other investigators.

The conclusions answered the aim of the investigation in a straightforward way. My only comment about the discussion is that the use of CBCT for results evaluation should be addressed and defended clearly as regards of the x ray dose and how far it is safe to the patients as compared to other radiographs (Lateral cephalograms and panoramic views) The study limitations mentioned could be done in future long-term studies that may extends to a long post treatment period.

The study as a whole is very good and highlighted an extremely important point to the orthodontic profession, which is the way to accelerate the orthodontic tooth movement and consequently decrease the treatment time.

To make this study stronger it could be possible if the authors used and compared other non-surgical methods to accelerate the orthodontic teeth movements like: low‐intensity laser irradiation, resonance vibration, pulsed electromagnetic fields, electrical currents and pharmacological approaches