Sixty patients requiring extraction-based treatment of the maxillary first premolars, followed by retraction of the maxillary canines, will be randomly assigned to three groups: piezocision, low-level laser therapy, and control. In each group, canine retraction will be initiated after completion of the leveling and alignment phase, using closed nickel-titanium coil springs that apply 150 g of force per side. For anchorage, a soldered transpalatal arch will be used.

Pre- and post-distalization dental casts will be assessed to evaluate the rate of canine retraction, canine rotation, and anchorage loss over the follow-up period until a Class I canine relationship is achieved. Periodontal health will be assessed before and after canine retraction by evaluating the following parameters: plaque index, gingival index, bleeding index, and probing depth.

Before enrollment of each subject in the study, they will undergo a comprehensive assessment to ensure their eligibility. The operator will inform them of the study's aim and request written informed consent.

At the end of the leveling and alignment stage, the upper first premolars will be extracted. The rectangular stainless steel archwires (0.019" × 0.025") will be inserted, and after one month, canine retraction will be initiated.

Regarding the Piezocision, after anesthesia, three vertical incisions will be made (3-mm depth and 8-10 mm length) mesial and distal to the upper canine, as well as at an equal distance from the upper canine and the 2nd premolar. The surgical procedures will be repeated after six weeks (only the mesial and distal canine incisions will be done) Regarding low-level laser therapy (LLLT), a GaAlAs diode laser (wavelength: 810 nm; exposure time: 10 seconds per point) will be applied around the upper canine at 10 sites, buccally and palatally. The central portion of the extraction site will also be irradiated at four sites (2 buccally and two palatally). LLLT will be applied 5 times during the first month of canine retraction, then every 2 weeks until a Class I canine relationship is 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 is present on both sides.

Dental casts will be used to quantify the anteroposterior movement of the upper canines and first molars at 30-day intervals until the Class I canine relationship is achieved.

Inclusion Criteria:

1. Adult healthy patients, Male and female, Age range: 17-28 years.

2. Class II Division 1 malocclusion :

   • Mild/moderate skeletal Class II (sagittal discrepancy angle ≤7)
   • Overjet ≤10
   • Normal or excessive facial height (Clinically and then cephalometrically assessed using these three angles: mandibular/cranial base angle, maxillary/mandibular plane angle, and facial axis angle)
   • Mild to moderate crowding ≤ 4

3. Permanent occlusion.

4. Existence of all the upper teeth (except third molars).

5. Good oral and periodontal health:

   • Probing depth < 4 mm
   • No radiographic evidence of bone loss.
   • Gingival index ≤ 1
   • Plaque index ≤ 1

Exclusion Criteria:

1. Medical problems that affect tooth movement (corticosteroid, nonsteroidal anti-inflammatory drugs (NSAIDs), …)

2. Presence of primary teeth in the maxillary arch

3. Missing permanent maxillary teeth (except third molars).

4. Poor oral hygiene or Current periodontal disease:

   • Probing depth ≥ 4 mm
   • radiographic evidence of bone loss
   • Gingival index > 1
   • Plaque index > 1

5. Patient had previous orthodontic treatment