The present clinical comparative study will be undertaken for assessment of two different modalities of maxillary canine retraction assisted with microosteoperforations versus injectable platelet rich fibrin.

Group I: will include 9 patients who willreceive MOPs with maxillary canine retraction that will be performed on intervention sides according to a standardized protocol.

▪ Group II: will include 9 patients receive i-PRF that will be performed on intervention sides according to a standardized protocol.

Inclusion Criteria:

1. An age ranges from 15-22 years.
2. Severe crowding or protrusion requiring 1st premolars extractions followed by symmetrical canine retraction.
3. All permanent teeth present, 3rd molars are excluded.
4. Good oral and general health.
5. No systemic disease/medication that could interfere with OTM.
6. No previous orthodontic treatment.

Exclusion Criteria:

1. Patient diagnosed to have an indication for non-extraction approach.
2. Poor oral hygiene or periodontally compromised patient.
3. Patient with craniofacial anomalies or previous history of trauma, bruxism or parafunctions.
4. Previous orthodontic treatment.