Photobiomodulation Effect on Vietnamese Orthodontic Patients

During the orthodontic treatment period, patients must endure various discomforts, such as the risk of inflammatory root resorption and frequent pain, which typically occur due to the body's inflammatory response to the applied forces. Pain is commonly managed with non-steroidal anti-inflammatory drugs (NSAIDs) or acetaminophen; however, these medications may induce adverse effects and potentially inhibit tooth movement. Photobiomodulation (PBM) therapy using light-emitting diodes (LEDs) has emerged as a non-pharmacological approach that may reduce pain, enhance tooth movement, and lower the risk of root resorption.

The objective of this randomized, placebo-controlled clinical trial is to evaluate the effects of LED PBM on pain reduction, enhancement of tooth movement, and mitigation of root resorption risk during orthodontic treatment. Sixteen participants aged 11 to 30 years undergoing fixed orthodontic treatment were randomly assigned to either the intervention group or the placebo group. In the intervention group, patients used the LED device for 10 minutes per day (5 minutes for the upper arch and 5 minutes for the lower arch) every day. In the placebo group, patients used a sham LED device (without a charging case) following the same procedure, 10 minutes per day. Patients in both groups were blinded to the light status while wearing the device. After finishing the aligning and leveling stage with Nickel and Titanium (NiTi) arch wires, during the phase of canine distalization with stainless steel arch wires, patients were assessed at four consecutive follow-up visits, scheduled at monthly intervals.

Canine movement was measured by superimposing sequential 3D digital scans obtained over these four visits using 3D Slicer software. Saliva and gingival crevicular fluid (GCF) samples were collected at each follow-up visit to measure dentin sialoprotein (DSP), a biomarker of root resorption in humans. Additionally, at each visit, patients' pain intensity was measured using the Visual Analog Scale (VAS) to establish the baseline for that follow-up (0 hour), and then measured again at 24 hours and 48 hours post-visit. The primary outcomes are differences between groups in canine displacement, pain intensity, and DSP concentration in both saliva and GCF.

The findings of this study may support the clinical application of LED PBM as a safe, non-invasive, and drug-free adjunctive therapy to improve patient comfort and reduce treatment-related risks during orthodontic care, particularly in Vietnamese patients.

Inclusion criteria

• Patients aged 11-30 years old who were required to undergo extraction of four premolars for orthodontic purposes.
• Four canines erupted in both arches.
• No active caries, no gingivitis, or periodontal disease was diagnosed through clinical examination and panoramic X-ray.
• No history of previous orthodontic treatment.
• No abnormality in tooth shape, number, or size.

Exclusion criteria

• Patients who smoked, had systemic diseases, and/or were using medications that could affect pain sensation.
• Patients who are diagnosed with severe root resorption based on their panorama X-ray image.