One of the main goals of orthodontic treatment is the reduction of treatment time through faster tooth movement. The previous studies evaluating platelet-rich fibrin (PRF) and orthodontic tooth movement (OTM) are limited, which makes the results difficult to generalize.

One of the main goals of orthodontic treatment is the reduction of treatment time through faster tooth movement. The previous studies evaluating platelet-rich fibrin (PRF) and orthodontic tooth movement (OTM) are limited, which makes the results difficult to generalize. To this end, we set up this Randomized experiment to evaluate the effect of the injectable form of PRF (i-PRF) on OTM, using nonadditive containing i-PRF, which has higher levels of regenerative cells and growth factors compared with other PRF types because of the use of low centrifugation spee. Accordingly, we aimed to evaluate the effect of i-PRF on the rate of maxillary incisors leveling during comprehensive orthodontic treatment.

Inclusion Criteria:

• The patient's age (18-26). Severe or very severe irregularity of the upper incisors greater than (7 mm) according to Little's index, so it is recommended to extract the upper first premolar.

  • Class I or Class II malocclusion, first model according to Angle, with skeletal class I or II and a normal or mild vertical growth pattern.
  • All permanent upper teeth, up to the first molar, are present, with the possibility of attaching brackets to all teeth in a correct position.
  • The patient has good oral health.

Exclusion Criteria:

• • The presence of any systemic disease that affects orthodontic dental movement.

  • Severe malalignment of one of the teeth (palatal quadrant, ectopic canine, ectopic premolar).
  • The patient has undergone previous orthodontic treatment.
  • The patient is subject to any drug treatment that may affect orthodontic dental movement (cortisone, non-steroidal anti-inflammatory drugs).
  • The patient has poor oral health.
  • Commitment to periodic follow-up appointments.