Letter to the Editor
To: Editor, The Angle Orthodontist
Re: Comparison of anterior retraction and anchorage control between en masse retraction and two-step retraction: A randomized prospective clinical trial. Patricia Pigato Schneider, Luiz Gonzaga Gandini Junior, Andre da Costa Monini, Ary dos Santos Pinto, Ki Beom Kim. The Angle Orthodontist. 2019 Mar;89(2):190-199
We thank the authors for publishing this clinical research comparing en masse retraction (ER) and two step retraction (TSR). This was an extensive clinical study and we have a few questions regarding the objectives and methodology:
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This study used 0.017″ x 0.025″ ss wires for both the ER and TSR groups during space closure. The results showed that there was more tipping movement and less apical displacement. Can you explain why you chose that wire and do you think that use of 0.019″ x 0.025″ SS wires in 022″ slot might have provided better anchorage, control of vertical position of the incisors and translation type of tooth movement?
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In the study, the extraction of premolars was performed after aligning. The inclusion criteria defined mild to moderate crowding. If the extraction of premolars had been accomplished prior to bonding, the use of lacebacks would have prevented any further flaring of incisors while aligning. Do you think this would have changed the results?
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Though the sample size was clinically relevant, the details of sample size estimation were not provided (reference to previous studies or power analysis/formula used for sample size estimation).
The use of oblique cephalometric radiographs at 45 degrees and the notable clinical significance and relevance of this study for contemporary orthodontics were commendable features of this research. Thank you for publishing this study.