Tainá Caroline dos Santos Malavazzi

This clinical, randomized, controlled, and blinded trial evaluated photobiomodulation (PBM) using 850 nm (infrared) and 660 nm (red) LED clusters on cervical and mandibular mobility and masticatory muscles in temporomandibular disorder (TMD) patients. PBM was applied to the temporomandibular joint (TMJ) region, masseter, temporal, scalene, and trapezius muscles over six non‐consecutive sessions over 2 weeks. The Research Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were used to determine the presence of TMD. A caliper and goniometer were used to measure the mandibular and cervical range of motion, respectively. Pain was assessed with the visual analog scale (VAS) before and after intervention. Results showed pain reduction only in the LED group post‐intervention; the placebo group showed no difference. No differences were observed in mouth opening, right laterality, flexion, or extension between groups, but left laterality increased in the LED group. In conclusion, PBM with LEDs effectively reduced pain in TMD patients. Trial Registration: ClinicalTrials.gov identifier: NCT06068959

Muscle injuries involve a complex inflammatory response in which macrophages are essential for proper tissue repair. Dysregulation of this process can impair regeneration. This study investigated the effects of vascular photobiomodulation (VPBM), a non‐invasive therapy applied via the caudal vein/artery, on macrophage dynamics in acute skeletal muscle injury. Wistar rats were divided into Control, Injury, Pre‐VPBM+Injury, and Injury+Post‐VPBM groups. VPBM (780 nm, 40 mW, 3.2 J) was applied preventively or therapeutically. Animals were euthanized on days 1, 2, 5, and 7 post‐injury for CD68 ⁺ and CD206 ⁺ immunostaining. CD68 ⁺ cells peaked on day 1 in the Pre‐VPBM+Injury group, while the Injury group maintained higher levels at day 7. CD206 ⁺ cells were elevated early in both VPBM groups, especially Pre‐VPBM. On day 7, CD206 ⁺ remained higher in the Injury group, indicating delayed resolution. In summary, the study demonstrates that preventive VPBM application accelerates macrophage recruitment and promotes a pro‐regenerative inflammatory response.

This study aims to assess the effects of aquatic training (AT) and its combination with photobiomodulation (PBM) on cytokine synthesis and plantar muscle morphology during compensatory hypertrophy (H) in Wistar rats. H was induced by bilateral ablation of synergistic muscles, and PBM using a laser (780 nm). AT involved 60 min sessions, 5 times/week, for 7 and 14 days. Muscle weight relative to body weight did not differ significantly between groups. TNF-α synthesis levels decreased in the H + AT + PBM group at 7 days compared to H Control. IL-6 and IL-1β levels showed no significant changes. Cross-sectional area (CSA) was higher in H + AT + PBM at 7 days and 14 days compared to H + AT and H Control. Fiber diameter increased in H + AT and H + AT + PBM compared to H at 14 days. AT with PBM decreased TNF-α expression, increased CSA and fiber diameter, whereas AT alone increased fiber diameter. In conclusion, the combination of photobiomodulation (PBM) therapy and aquatic training (AT) effectively reduced TNF-α levels while increasing muscle fiber diameter and cross-sectional area (CSA). Furthermore, AT alone demonstrated the capacity to maintain fiber diameter. Graphical abstract

Introduction The prevention of diabetic foot ulcer (DFU) involves the classification of risk, systemic care, regular examinations, foot care, therapeutic education and adjunct treatments. Photobiomodulation (PBM) has been successfully administered for the healing of DFU and its preventive effects have drawn the interest of researchers. Methods and analysis The purpose of the study is to assess the effect of PBM for the prevention of DFU through a randomised, controlled, double-blind, clinical trial. Individuals from 18 to 75 years of age of both sexes with type 2 diabetes mellitus (DM) at moderate to high risk of developing DFU will be randomly allocated to two groups of 32 participants each. The PBM group will wear a boot with 1344 light-emitting diodes (LEDs)—504 with a wavelength of 660 nm located on the sides of the boot (28.5 mW, 10 J per LED), 504 with a wavelength of 850 nm also on the sides of the boot (23 mW, 8 J per LED), 168 with a wavelength of 660 nm on the base of the boot (28.5 mW, 10 J per LED) and 168 with a wavelength of 850 nm also on the base of the boot (23 mW, 8 J per LED). The boot will be worn once a day for 6 min over 60 days and the participants will also receive therapeutic education. The control group will wear a non-therapeutic LED boot (sham) under the same conditions and will also receive therapeutic education. Assessments will be performed at the beginning of the study, after 30 days (clinical examination) and after 60 days (clinical examination, assessment of peripheral neuropathy (PN) and peripheral artery disease (PAD), blood and urine examinations and quality of life). Ethics and dissemination This protocol received approval from the Human Research Ethics Committee of Nove de Julho University and the Mandaqui Hospital Complex (certificate number: 66098522.0.3001.5511; final approval date: 22 June 2023). The findings will be published in a peer-reviewed journal. Trial registration number NCT06353568, ClinicalTrials.gov.

This study investigated the effects of photobiomodulation (PBM) in acceleration of orthodontic movement of inferior molar uprighting movement. Thirty‐four individuals, with indication of molar uprighting movement for oral rehabilitation, were randomly divided in two groups: verticalization + PBM (808 nm, 100 mW, 1 J per point, 10 points and 25 J/cm²) or verticalization + PBM simulation. Elastomeric chain ligatures were changed every 30 days for 3 months. FBM was performed immediately, 24 h, 72 h, 1 and 2 months after activation. The primary outcome was the amount of uprighting movement. Secondary outcomes were pain, amount of medication, OHIP‐14 questionnaire, and cytokine IL‐1β. PBM group increase uprighting movement when compared to control after 3 months and modulate IL‐1β expression. For pain control, the amount of medication and OHIP‐14 no difference were found. This study suggests that PBM accelerates tooth movement during molar uprighting, due to modulation of IL‐1β during bone remodeling.

Background: This study aimed to evaluate the electrical activity of the rectus femoris, tibialis anterior, and lateral gastrocnemius muscles during the sit-to-stand task and functional mobility after a neurofunctional physiotherapy protocol associated with PBM. Methods: Twenty-five children were randomly allocated to either Active PBM + physiotherapy (n = 13) or PBM sham + physiotherapy (n = 12). PBM was carried out with a LED device (850 nm, 25 J, 50 s per point and 200 mW) at four points over the area with absence of a spiny process. Both groups completed a twelve-week supervised program with two weekly 45–60 min sessions. Pre-training and post-training assessments involved the Pediatric Evaluation of Disability Inventory (PEDI). Muscle activity was assessed using portable electromyography (BTS Engineering) and the electrodes were positioned on the lateral gastrocnemius, anterior tibialis, and rectus femoris muscles. The RMS data were recorded and analyzed. Results: After 24 sessions of the treatment protocol, improvements were found in the PEDI score. The participants presented greater independence in performing the tasks, requiring less assistance from their caregivers. More significant electrical activity was found in the three muscles evaluated between the rest period and execution of the sit-to-stand tasks, both in the more compromised or less compromised lower limbs. Conclusion: Neurofunctional physiotherapy with or without PBM improved functional mobility and electrical muscle activity in children with myelomeningocele.

The local photobiomodulation (LPBM) has demonstrated positive effects during compensatory hypertrophy (CH) in skeletal muscle as a response to an overload. The aim was to compare the effects of the transcutaneous vascular photobiomodulation (VPBM) and the LPBM on muscle fiber size, gait functionality, and on mechanical sensitivity during the CH model in rats. VPBM was administered over the rat's main tail vein and LPBM was applied over the plantar muscle region. VPBM induced an increase in muscle fiber diameter and cross‐sectional area (CSA) after 7 days. At 14 days, an increase in the fiber diameter was found in both irradiated groups. The VPBM and LPBM promoted the reestablishment of normal gait evaluated by the sciatic functional index after 14 days. No changes were found in the mechanical (nociceptive) sensitivity in VPBM and LPBM groups in comparison to the CH group but there was an increase in the nociceptive sensitivity in the CH groups in comparison to the control after 7 and 14 days. In conclusion, both PBM, vascular and local, were able to improve the muscle size and gait during the CH process with more pronounced effects when irradiation was performed systemically (VPBM).

Photobiomodulation (PBM) has demonstrated positive effects on the muscle repair process. The aim of the study was to evaluate the effects of infrared PBM using different light sources—low-level laser (LLL) at 780 nm (40 or 70 mW, 10 J/cm², 0.4 J) or LED at 850 nm (40 or 70 mW, 0.13 J/cm², 0.4 J)—and dosimetric parameters on the proliferation and migration of muscle cells. The results showed that LLL 40 mW and 70 mW, with the same radiation exposure, led to an increase in proliferation after 24 h, but no differences at 48 and 72 h. Cells irradiated with LED 70 mW exhibited an increase in proliferation in comparison to the control group and 40mW after 24 and 48 h, but not at 72 h. Moreover, cell migration was greater in comparison to the control after 6 and 24 h, and no differences were found at 12 h when LLL was used with an output power of 70 mW. Furthermore, no differences were found at 6 and 12 h with the 70 mW output power-LED, but an increase was observed in the cell migration after 24 h. In conclusion, PBM using different light sources and dosimetric parameters was able to modulate the proliferation of C2C12 myoblasts, but only PBM at 70 mW was able to modulate the migration of these cells.

Introdução: As lesões nervosas periféricas (LNP) podem resultar em distúrbios motores e sensoriais alterando a funcionalidade do membro afetado, porém pouco se conhece a respeito dos efeitos da fotobiomodulação (FBM) com diodo emissor de luz (LED). Objetivo: Analisar os efeitos do LED sobre a funcionalidade da marcha de ratos Wistar pós LNP. Metodologia: Ratos Wistar foram submetidos a LNP por esmagamento de ciático e analisados nos seguintes grupos experimentais: (1) Controle; (2) LNP; (3) LNP+ LED (780 nm, potência média 40 mW, exposição radiante, energia por ponto, 3,2 J sobre o nervo ciático (LEDn); (4) LNP+ LED em nervo e região do músculo envolvido (LEDnm) e (5) LNP+ LED apenas em região do músculo (LEDm). Após 7, 14, 21 e 28 dias foram realizadas as análises de marcha utilizando o Índice Funcional Ciático (IFC). Resultado: Após 7 dias, os grupos tratados com LED apresentaram uma melhora da marcha em relação ao grupo Lesão, sendo essa melhora mais pronunciada no grupo LEDn. Após 14 dias, os grupos LEDn e LEDnm apresentaram valores semelhantes ao grupo controle e após 21 e 28 dias o IFC não apresentou diferenças entre os grupos experimentais. Conclusão: O LED aumentou a funcionalidade da marcha avaliada pelo IFC após 1 e 2 semanas pós LNP, especialmente quando foi usado na região nervosa associada ou não à região muscular.

This systematic review investigated the repercussions of photobiomodulation using low‐level laser therapy (LLLT) for the treatment of spinal cord injury (SCI) in experimental models. Studies were identified from relevant databases published between January 2009 and December 2021. Nineteen original articles were selected and 68.4% used light at an infrared wavelength. There was a considerable variation of the power used (from 25 to 200 mW), total application time (8–3000 s) and total energy (0.3–450 J). In 79% of the studies, irradiation was initiated immediately after or within 2 h of the SCI, and treatment time ranged continuously from 5 to 21 days. In conclusion, LLLT can be an auxiliary therapy in the treatment of SCI, playing a neuroprotective role, enabling functional recovery, increasing the concentration of nerve connections around the injury site and reducing pro‐inflammatory cytokines. However, there is a need for standardization in the dosimetric parameters.