Before enrollment of each subject into the study, they will be examined completely to ensure their eligibility for this study. The operator will inform them about the aim of the study and ask them to provide written informed consent.~At the end of leveling and alignment stage, the upper first premolars will be extracted. The rectangular stainless steel archwires (0.019 × 0.025) will be inserted, then after one month, the canine retraction will be started.~Regarding the Piezocision, after anesthesia, three vertical incisions will be made (3-mm depth and 8-10 mm length) mesial and distal the upper canine as well as at an equal distance from the upper canine and 2nd premolar. The surgical procedures will be repeated after six weeks (only the mesial and distal canine incisions will be done) Regarding the low-level laser therapy (LLLT): GaALAs diode laser (wavelength: 810 nm and exposure time of 10 seconds\point) will be applied around the upper canine in 10 sites from buccal and palatal. The middle of the extraction site will be also irradiated in 4 sites (2 buccally and 2 palatally). The LLLT will be applied 5 times in the first month of canine retraction, then every two weeks until class I canine relationship will be achieved.~The upper canine destalization will be done using NiTi springs. The force level will be controlled every 2 weeks. Retraction will be stopped when a class I canine relationship in both sides.~Dental casts will be used for the quantification of the anteroposterior movement of the upper canine and the first molars every 30 days until the class I canine relationship will be achieved.
Sixty patients need extraction-based treatment of the maxillary first premolars with subsequent retraction of the maxillary canines will be divided randomly into three groups: piezocision group, low-level laser therapy group, and control group. In each group, the canine retraction will be started after completion of the leveling and alignment phase via closed nickel-titanium coil springs applying 150 g of force per side. For anchorage, a soldered trans-palatal arch will be used.~Pre- and post distalization dental casts will be assessed to study the rate of canine retraction, as well as, canine rotation and anchorage loss over a follow-up period until a class I canine relationship is achieved.