INTERVENTION
After obtaining complete pretreatment records and thorough oral prophylaxis, all
patients started an orthodontic treatment procedure by one orthodontist, to
prevent operator bias, using pre-adjusted Edgewise brackets (MBT 0.022-in slot).
A soldered transpalatal arch (TPA), fabricated with 0.9mm stainless steel (SS)
wire was used for anchorage reinforcement and maintenance of the transverse
dimension. Leveling and alignment was started with a 0.014-in NiTi archwire, and
completed when a 0.016×0.022-in SS archwire was placed for one month. Following,
atraumatic extractions of maxillary first premolars and placement of L-PRF plugs
were performed. NiTi closed-coil springs (Ormco
