Effects of laser photobiomodulation on tgf-ß and vegf expression in burn wound: systematic review and meta-analysis in the animal model / Influencia de la fotobiomodulación por láser en la expresión de tgf-ß y vegf en heridas por quemadura: revisión sistemática y meta-análisis en modelo animal

SUMMARY: Laser photobiomodulation (laser PBM) is known to be able to accelerate burn wound healing in the animal model; however little evidence exists on the action of laser PBM on the expression of important proteins in wound healing in the animal model, such as VEGF and TGF-ß1. The aim of this study was to carry out a systematic review in order to analyse the effect of laser PBM on VEGF and TGF-ß expression during burn wound repair in the animal model. A systematic review was carried out of the EMBASE, PubMed/ MEDLINE and LILACS databases. The studies included were preclinical studies that analysed the action of laser PBM on the expression of VEGF and TGF-ß (1, 2, 3) during burn wound repair in the animal model. The SYRCLE risk of bias tool was used. Random effect models were used to estimate the combined effect. Increased VEGF expression was observed with the use of laser PBM at 4.93 J/cm2 per point in the first two weeks after induction of the burn wound, with greater size of effect in the second week (SDM = 5.72; 95% CI: 3.14 to 8.31, I2 = 0 %; very low certainty of evidence). We also observed that the effect of laser PBM on TGF-ß1 expression was greater than in the control in the first week (SDM = -0.45; 95% CI: -1.91 to 1.02, I2 = 51 %; very low certainty of evidence), but diminished in the third week after induction of the lesion (SDM = -2.50; 95% CI: 3.98 to -1.01, I2 = 0 %; very low certainty of evidence). Laser PBM has an effect on TGF-ß1 and VEGF expression, promoting burn wound repair in the animal model.

RESUMEN: Es sabido que la fotobiomodulación por láser (FBM láser) puede acelerar el proceso de curación de heridas por quemadura en modelo animal, sin embargo aún se carece de mayor evidencia sobre la acción de la FBM láser en la expresión de proteínas importantes en el proceso de curación de heridas en modelo animal, como VEGF y TGF-ß1. Así, el objetivo de este estudio fue realizar una revisión sistemática a fin de analizar el efecto de la FBM láser sobre la expresión de VEGF, TGF-ß durante el proceso de reparación de heridas por quemadura en modelo animal. Se realizó una búsqueda sistemática en las bases de datos EMBASE, PubMed/MEDLINE y LILACS. Se incluyeron estudios preclínicos que analizaron la acción de la FBM láser en la expresión de VEGF, TGF-ß (1, 2, 3) durante el proceso de reparación de heridas por quemadura en modelo animal. Se utilizó la herramienta de riesgo de sesgo SYRCLE. Se utilizaron modelos de efectos aleatorios para estimar el efecto combinado. Observamos aumento de la expresión de VEGF con el uso de FBM láser 4.93 J/cm2 por punto, en las dos primeras semanas tras inducción de la herida por quemadura, con mayor tamaño de efecto en la segunda semana (SDM = 5,72; IC del 95%: 3,14 a 8,31, I2 = 0 %; certeza de la evidencia muy baja). También se observó el efecto de la FBM láser en la expresión del TGF- ß1 que fue mayor que el control en la primera semana (SDM = - 0,45; IC del 95%: -1,91 a 1,02, I2 = 51 %; certeza de la evidencia muy baja), disminuyendo en la tercera semana tras inducción de la lesión (SDM = -2,50; IC del 95%: -3,98 a -1,01; I2 = 0 %; certeza de la evidencia baja). La TFB por láser ejerce influencia en la expresión de TGF-ß1 y VEGF favoreciendo el proceso de reparación de heridas por quemadura en modelo animal.

Photobiomodulation Therapy in Burn Wound Healing: Systematic Review and Meta-Analysis of Preclinical Studies.

Background and objective: To determine the effectiveness of photobiomodulation therapy (PBMT) in the burn wound healing compared with the control or with the use of antibiotics, in animal models. Materials and methods: A systematic search was conducted in EMBASE, MEDLINE, and LILACS databases. Preclinical studies were included that analyzed the effectiveness of PBMT in the burn wound healing, which assessed wound contraction, angiogenesis, proliferation of fibroblasts, and collagen deposition. SYRCLE risk of bias tool was used. Random effects models were used to estimate the pooled effect. Results: Thirty-eight studies were included. PBMT favored wound contraction (mean difference = -11.47, 95% confidence interval -19.87 to -3.08, I2 = 0%; moderate certainty of evidence). PBMT also favored angiogenesis at doses between 11 and 20 J/cm2, and increased the collagenization rate. Conclusions: In animal models, PBMT favored wound contraction, angiogenesis, and collagen deposition in second- and third-degree burn wounds.

Increased Oral Health-Related Quality of Life Postsynergistic Treatment with Ultrasound and Photobiomodulation Therapy in Patients with Temporomandibular Disorders.

Background and objective: The object of this study was to analyze the oral health-related quality of life (OHRQoL) of patients with temporomandibular disorders (TMDs) who were treated simultaneously with ultrasound (US) and photobiomodulation therapy (PBMT). Materials and methods: This study included 13 patients of both genders, with diagnosis of TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders. The patients were treated with equipment consisting of US and PBMT in the same system. The treatment was applied to the left and right sides of the face in the masseter muscle, anterior temporalis muscle, and temporomandibular joint, two sessions per week for a total of eight sessions. The OHRQoL was assessed by the Oral Health Impact Profile (OHIP-14) at three moments: pretreatment (T0), after the eight treatment sessions (T1), and 30 days after termination of treatment (T2). The Wilcoxon, Mann-Whitney U, Kruskall-Wallis, and Spearman's correlation coefficient tests were applied, with a significance threshold of 5%. Results: Psychological discomfort, physical pain, and psychological limitation were the domains where the highest scores were obtained at T0. The total OHIP-14 scores at T1 and T2 were significantly lower than at T0. No statistical differences were observed between T1 and T2. Conclusions: We conclude that synergistic treatment was effective in improving the OHRQoL of patients with TMDs, and that its beneficial effects persisted at 1 month after termination of treatment.

Effects of low-level laser on the repair of orthodontically induced inflammatory root resorption: a systematic review of studies in rats / Efectos del láser de bajo nivel en la reparación de la reabsorción radicular inflamatoria inducida por ortodoncia: una revisión sistemática de estudios en ratas

Orthodontically induced inflammatory root resorption (OIIRR) is a complication of dental treatment which consists of the degradation of local tissue due to an inflammatory reaction provoked by inappropriate orthodontic stimulus. The aim of the present systematic review was to assess the effectiveness of low-level laser therapy (LLLT) in reducing orthodontically induced inflammatory root resorption (OIIRR) in animal models. A systematic review was carried out in the MEDLINE, EMBASE and LILACS databases. Studies of interventions in animals were selected which analysed the effect of LLLT on OIIRR repair. The risk of bias was analysed through the 10 domains of the SYRCLE RoB tool for animal studies. Seventy-one studies were found; 27 were eliminated as duplicates and 44 titles/abstracts were analysed. Of these, 38 were excluded, and five studies were included for qualitative analysis. In 66.6 % of the studies included, the authors state that LLLT was effective in the inhibition/repair of OIIRR. In histological analysis it was observed that root resorption was significantly less in animals treated with laser as compared to the control. Furthermore, LLLT accelerated cicatrization after OIIRR. Laser proved effective in reducing root resorption lacunae and shortening the inflammatory process induced by the application of orthodontic force.

La resorción radicular inflamatoria inducida por tratamiento ortodontico (RRIITO) es una complicación del tratamiento odontológico que consiste en la degradación del tejido local debido a una reacción inflamación provocada por un estímulo ortodóntico inadecuado. El objetivo fue analizar la efectividad de la terapia láser de baja intensidad (LBI) en la disminución de RRIITO en ratas. Se realizó una revisión sistemática en las bases MEDLINE, EMBASE y LILACS. Fueron utilizados los términos 'resorción radicular', 'láser de baja intensidad', 'fototerapia', 'tratamiento ortodóntico', 'movimiento dental'. Fueron seleccionados estudios de intervención en animales, que analizaron el efecto del LBI en la reparación de la RRIITO. Los riesgos de sesgos fueron analizados mediante los 10 domínios de la herramienta SYRCLE RoB para estudios en animales. 71 estudios fueron encontrados, siendo eliminados 27 duplicados, y analizados 44 títulos/abstracts; de estos, fueron incluídos 5 estudios para análisis cualitativa. El 66,6 % de los estudios incluidos afirman que el LBI fue efectivo em reparar la RRIITO. En el análisis histológico se observó que la RRIITO fue significativamente menor en animales tratados con láser en comparación con el control. Además de eso, el LBI aceleró el proceso de cicatrización de la RRIITO. El láser se mostró efectivo en reducir las lagunas de resorción radicular y acortar el proceso inflamatorio inducido por la aplicación de fuerzas ortodonticas.

Effectiveness of Low-Level Laser Therapy in Reducing Orthodontic Pain: A Systematic Review and Meta-Analysis.

OBJECTIVES: To assess the effectiveness of low-level laser therapy (LLLT) in reducing orthodontic pain after the application of orthodontic force (OF). METHODS: A systematic search was conducted in the MEDLINE, EMBASE, Scopus, Cochrane Library, Web of Science, and EBSCOhost databases. The study included randomized clinical trials (RCT) which analysed the effectiveness of LLLT in reducing orthodontic pain assessed at 24 and 72 hrs after the application of OF. The risk of bias of the eligible trials was assessed using the Cochrane Collaboration's risk of bias tool. Standard mean difference was calculated and pooled by meta-analysis using random effect models. RESULTS: Of 467 identified articles, 20 RCT were finally included. In the risk of bias assessments, 13 studies presented a high risk, 5 an unclear risk, and 2 a low risk. The meta-analysis showed that in patients treated with laser versus placebo there was a difference in favour of LLLT in spontaneous pain 24 and 72 hrs after the installation of light archwires and spontaneous pain and chewing pain 24 and 72 hrs after the installation of elastomeric separators. CONCLUSIONS: LLLT proved to be effective in promoting a reduction in spontaneous and chewing pain after the application of OF; however, the poor quality of the evidence requires these results to be treated with caution.

Electromyographic study of the masseter muscle after low-level laser therapy in patients undergoing extraction of retained lower third molars / Estudio electromiográfico del músculo masetero tras terapia con láser de baja intensidad en pacientes sometidos a extracción de tercer molar mandibular retenido

The surgery for extraction of the retained lower third molar is one of the most commonly performed procedures in the field of maxillofacial surgery. During this procedure, the surgical trauma can cause damage to the function of muscles involved in mandibular movements, such as the masseter muscle. In order to accelerate post-surgical recovery, many physiotherapy resources are employed, including laser therapy. The aim was to analyze the electrical activity of the masseter muscle treated with Low-level Laser (LLL) after surgical trauma. Assessments of masseter muscle on a sample of 60 patients were performed by surface electromyography in four instances: immediate preoperative, postoperative at 7, 14 and 21 days. The patients were divided into two groups: 1- untreated group with LLL in the postoperative; 2- group treated with LLL (810 nm; 10 J/cm2) in the immediate postoperative and at 3, 6 and 9 days after surgery. On the seventh day after surgery 23.3 % of the patients in the group receiving LLL showed recovery of their muscle activity as they presented in the immediate preoperative, versus only 3.3 % of the untreated group. On the 14th day, 73.3% of treated patients showed functional rehabilitation, versus 6.7% in the untreated group, and on the 21st, 80% versus 10% in the untreated group. On the 14th postoperative day the electrical activity of the masseter muscle treated with LLL after surgical trauma was compatible with a condition of complete functional recovery. The findings of this electromyographic study indicated that LLL proved to be an efficient physiotherapeutic method for stimulating the masseter muscle functional recovery after surgery of retained lower third molars.

La cirugía para extracción del tercer molar mandibular retenido es uno de los procedimientos más realizados en el campo de la cirugía maxilofacial. Durante este procedimiento, el trauma quirúrgico puede causar daño a la función de los músculos involucrados en los movimientos mandibulares, entre ellos el músculo masetero. Con el objetivo de acelerar la recuperación postoperatoria, son utilizados muchos recursos de fisioterapia, incluyendo la terapia con láser. El objetivo de este estudio fue analizar la actividad eléctrica del músculo masetero tratado con láser de baja intensidad (LBI) después del trauma quirúrgico. Se realizaron evaluaciones del músculo masetero en una muestra de 60 pacientes, a través de electromiografía de superficie en cuatro momentos: preoperatorio inmediato, postoperatorio a los 7, 14 y 21 días. Los pacientes fueron divididos en dos grupos: 1 - grupo no tratado con LBI en el postoperatorio; 2 - grupo tratado con LBI (810 nm; 10 J/cm2) en el postoperatorio inmediato y a los 3, 6 y 9 días tras cirugía. Al séptimo día tras cirugía el 23,3 % de los pacientes del grupo tratado con LBI presentaron recuperación de su actividad muscular equivalente a lo presentado en el preoperatorio inmediato, frente a sólo el 3,3 % del grupo no tratado. En el día 14, el 73,3% de los pacientes tratados presentaron rehabilitación funcional, frente al 6,7% del grupo no tratado y en el vigésimo primer día, el 80% frente al 10% del grupo no tratado. En el dia 14 postoperatorio la actividad eléctrica del músculo masetero tratado con LBI después del trauma quirúrgico fue compatible con una condición de recuperación funcional completa. Los hallazgos de este estudio electromiográfico indicaron que el LBI es un eficiente método fisioterápico para estimular la recuperación funcional del músculo masetero tras cirugía de terceros molares mandibulares retenidos.

Efectos del láser de baja intensidad (As-Ga-Al 904 nm) sobre el cóndilo mandibular de conejos: análisis a través de tomografía computadorizada cone beam / Effects of low-level laser (Ga-Al-As 904 nm) on the mandibular condyle of rabbits: analysis by cone beam computed tomography

En la literatura científica los efectos adversos del láser de baja intensidad (LBI) no están descritos de forma precisa, tampoco su inocuidad. El objetivo de este estudio fue evaluar el efecto de distintas dosis de LBI en el cóndilo mandibular de conejos. Dieciséis conejos divididos aleatoriamente en cuatro grupos experimentales (GE) de 4 animales fueron utilizados en este estudio. Se realizó un examen de tomografía computarizada cone beam (TCCB) de ambas articulaciones temporomandibulares (ATMs) de todos los animales que fueron utilizadas como control (GC). Luego, irradiamos cada ATM con LBI (As-Ga-Al 904 nm), 100 mW, spot 0,2 cm2, dos puntos, 3 veces/semana, totalizando 10 veces, con dosis de 15 J/cm2 (GE-1), 45 J/cm2 (GE-2), 60 J/ cm2 (GE-3) y 90 J/cm2 (GE-4). Después de 20 días de la última irradiación se realizó un nuevo examen de TCCB y luego se obtuvo las mediciones de los cóndilos en los planos coronal y sagital. Para el análisis estadístico se utilizó las pruebas de ANOVA y t-student. Los valores promedios encontrados para el GE fueron mayores que los encontrados para el GC, en los planos coronal y sagital. Hubo diferencia estadística significativa para el grupo 1 y entre los grupos 1 y 2. Concluimos que los valores promedios encontrados en las mediciones de los cóndilos mandibulares, sometidos a las dosis de LBI utilizadas en este estudio, fueron mayores que los encontrados para el GC en los planos coronal y sagital. Además, la TCCB demostró ser un método eficaz para el análisis de las dimensiones condilares.

In the scientific literature the adverse effects of Low Level Laser (LLL) are not precisely described, neither is their safety. The aim of this study was to evaluate the effect of different protocol doses of laser on the mandibular condyle of rabbits. Sixteen rabbits randomly divided into four experimental groups (EG) of 4 animals were used in this study. We carried out a cone beam computed tomography (CBCT) examination of both temporomandibular joints (TMJs) of all animals which were used as control. Subsequently, we radiated each TMJ with LLL (Ga-Al-As 904 nm), 100mW, spot 0.2 cm2, two points, 3 times/week, totaling 10 times, with doses of 15 J/cm2 (EG-1), 45 J/cm2 (EG-2), 60 J/cm2 (EG-3) and 90 J/cm2 (EG-4). After 20 days of the last irradiation we performed a new CBCT exam and then the measurement of the condyles on the coronal and sagittal planes was obtained. In the analysis of the results ANOVA and t-student for correlated samples was used. The average values found for the EG were higher than those found for CG for both the coronal and sagittal planes. There was a significant statistical difference for group 1 and between the groups 1 and 2. We concluded that the average values found in the measurements of the mandibular condyles, submitted to doses of LLL used in this study, were higher than those found for the control group in both the coronal and sagittal planes. Furthermore, the CBCT proved to be an effective method for analysis of condylar dimensions.