Diode Laser Versus LED for Maxillary Canine Retraction in Orthodontic Patients

This is an interventional split-mouth clinical study comparing diode laser and light-emitting diode (LED) photobiomodulation during maxillary canine retraction in patients undergoing fixed orthodontic treatment.

After alignment and leveling, maxillary canine retraction will be performed using standardized orthodontic mechanics. Each participant will receive both photobiomodulation interventions. One maxillary canine will receive diode laser photobiomodulation, while the contralateral maxillary canine will receive LED photobiomodulation according to the predefined side-allocation procedure. The interventions will be repeated at 4-week intervals during the 16-week observation period.

Digital intraoral scans will be obtained to quantify maxillary canine movement. Cumulative canine retraction will be assessed at 4, 8, 12, and 16 weeks. The amount and rate of canine retraction will be compared between the diode laser and LED sides within the same participant.

Pulp oxygen saturation (SpO₂) of the maxillary canines will be assessed to evaluate pulpal oxygenation during orthodontic tooth movement. SpO₂ measurements will be obtained separately from the canine receiving diode laser photobiomodulation and the contralateral canine receiving LED photobiomodulation at baseline, 20 minutes, 24 hours, 7 days, and 4 weeks after initiation of canine retraction. Changes from baseline and differences in SpO₂ between the two intervention sides will be evaluated.

Pain associated with orthodontic tooth movement will be assessed using a visual analog scale (VAS) after photobiomodulation. Cone-beam computed tomography (CBCT) examinations obtained before and after the canine retraction period will be used to evaluate changes in maxillary canine root length and alveolar bone dimensions.

Because both interventions are administered within the same participant, the split-mouth design allows direct within-participant comparison of diode laser and LED photobiomodulation while reducing the influence of interindividual biological variability.

Inclusion criteria

• Patients with complete permanent dentition and cervical vertebral maturation at CS5 or CS6 according to the Baccetti classification.
• Angle Class I malocclusion.
• Indication for fixed orthodontic treatment requiring bilateral extraction of the maxillary first premolars.
• Similar position, morphology, and dimensions of the maxillary canines on both sides.
• No previous orthodontic treatment.
• Willingness to participate in the study and provision of informed consent.

Exclusion criteria

• Patients with bleeding or coagulation disorders, diabetes mellitus, bone diseases, or periodontal diseases.
• Use of medications that may affect orthodontic tooth movement or coagulation, including aspirin, heparin, warfarin, nonsteroidal anti-inflammatory drugs, or glucocorticoids.
• History of maxillofacial trauma or craniofacial anomalies.
• Smoking.
• Pregnancy.
• Requirement for extraction of teeth other than the first premolars.