Effect of low-level laser therapy on tooth-related pain and somatosensory function evoked by orthodontic treatment

Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.

Variable spot size optical system for a dual-wavelength laser therapy device

The majority of existing high-power laser therapeutic instruments employ a single wavelength for a single target;thus,they do not meet the requirements for clinical treatment.Therefore,this study designs an optical system for a dual-wavelength high-power laser therapeutic device with a variable spot size.The waist of the short arm of the optical cavity and the G1G2 parameter(G-parameter equivalent cavity method)is calculated using MATLAB software,the spot size and divergence angle on the lens are calculated using an ABCD matrix,and the distance between the treatment spot at different spot sizes and the transformation lens is calculated in order to design the treatment handpiece.Experiments are conducted to analyze the stability at an output power of 532 nm before beam combination and the power loss after beam combination.The results show that the output power stability of the 532-nm beam varies by less than 2%over 150 min,and the loss of both wavelengths is less than 20%,which meets the clinical requirements of the system.The safety performance can meet the requirements of national general standards for medical electrical safety.The proposed dual-wavelength laser therapy instrument has both visible wave and near-infrared wave characteristics;thus,it can accurately target both superficial vessels and vessels with a larger diameter and deeper position.This therapeutic device has the advantages of simple operation,stable and reliable laser output,high security and strong anti-interference ability,and meets the comprehensive clinical treat-ment demands of vascular diseases.

Effect of low level laser therapy on dental pulp during orthodontic movement

AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth obtained from the middle root level were distributed in four groups: group 1(G1) absolute control; group 2(G2) only laser irradiation; group 3(G3) exposed only to orthodontics; and group 4(G4) treated with orthodontics and laser. Laser treatment was performed at 830 nm wavelength, 100 mW(energy 80 J/cm2, 2.2 J), for 22 s in the vestibular surface and 22 s in the palatal surface, 1 mm away from the dental root mucosa. Three staining methods were performed: hematoxylin-eosin(HE), Masson's Trichrome method and Gomori's method.RESULTS: The pulp histology parameters were evaluated and the results classified in to 3 parts: an inflammatory response, soft tissue response(dental pulp) and hard tissue response(dentin and predentin). There was no inflammation(chronic or acute) in any of the evaluated groups. The zones of pulp necrosis were found in one premolar of G3 and in one of G4; in groups G2 and G4 there was higher angiogenesis than in the other two groups. G4 group presented the highest level of vascularization. A reduced nerve density was observed in G3. A G2 specimen showed increased nerve density. A higher rate of calcification was observed in G1 compared to G2. Denticles, either real or false, were observed in G1, G2 and G3. Sclerosis of dentin and focal dentin loss was observed among all the groups. Secondary dentin was present in one sample in G1 and G2. A necrosis zone was found in one sample of G3 and G4. No differences between groups were observed in the odontoblast irregularity layer but the layer was wider in the group treated with laser only. A notable difference was detected in reduction of the cell-free layer between the groups G1 and G4. The findings in pulp tissue favor its adaptative response against dental movement induced by orthodontics. No definitive conclusions may be derived as this is a pilot study. CONCLUSION: The protocol described here was shown to be an effective method to evaluate changes in dental pulp submitted to low level laser in teeth under orthodontic movement.

Low-level laser therapy enhances the number of osteocytes in calvaria bone defects of ovariectomized rats

Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.

Neuroimmunomodulatory effects of transcranial laser therapy combined with intravenous tPA administration for acute cerebral ischemic injury

At present, the only FDA approved treatment for ischemic strokes is intravenous administration of tissue plasminogen activator within 4.5 hours of stroke onset. Owing to this brief window only a small percentage of patients receive tissue plasminogen activator. Transcranial laser therapy has been shown to be effective in animal models of acute ischemic stroke, resulting in significant improvement in neurological score and function. NEST-1 and NEST-2 clinical trials in human patients have demonstrated the safety and positive trends in efficacy of transcranial laser therapy for the treatment of ischemic stroke when initiated close to the time of stroke onset. Combining intravenous tissue plasminogen activator treatment with transcranial laser therapy may provide better functional outcomes. Statins given within 4 weeks of stroke onset improve stroke outcomes at 90 days compared to patients not given statins, and giving statins following transcranial laser therapy may provide an effective treatment for patients not able to be given tissue plasminogen activator due to time constraints.

Laser therapy versus intravitreal injection of anti-VEGF agents in monotherapy of ROP:a Meta-analysis

AIM:To compare the efficacy and safety between laser therapy and anti-vascular endothelial growth factor(VEGF)agents intravitreal injection monotherapy in type-1 retinopathy of prematurity(ROP)and aggressive posterior retinopathy of prematurity(APROP).METHODS:A systematic literature search was performed in PubMed,Cochrane Library,and Embase for original comparable studies.We included studies that compare laser therapy and intravitreal injections of anti-VEGF agents monotherapy in ROP regardless of languages and publication types.RESULTS:Complication incidence was significantly higher in laser therapy group(OR:0.38;95%CI:0.19-0.75;P=0.005).Spherical equivalent(SE)was higher in laser therapy[weighted mean difference(WMD):2.40,95%CI:0.88-3.93;P=0.002].The time between treatment and retreatment was longer in laser therapy group(WMD:8.45,95%CI:5.35-11.55;P<0.00001).Recurrence incidence(OR:0.97;95%CI:0.45-2.09;P=0.93)and retreatment incidence(OR:1.24;95%CI:0.56-2.73;P=0.59)were similar in two approaches.Subgroup analysis between type-1 ROP and APROP was not significant except SE reported in the included studies(P<0.0001).CONCLUSION:This Meta-analysis outcome indicates anti-VEGF agents are as effective as laser treatment,and safer than laser in type-1 ROP and APROP.The degree of myopia in APROP is higher than type-1 ROP.More randomized controlled trials in large sample size should be conducted in the future.

Effects of wavelength,beam type and size on cerebral low-level laser therapy by a Monte Carlo study on visible Chinese human

Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammation.Presently,the use of LLLT to treat stroke,traumnatic brain injury and cognitive dysfunction are attracting growing interest.Near infrared light is capable of penetrating into the cerebral cortex,allowing noninvasive treatments to be caried out with few treatment-related adverse events.Optimization of LLLT treatment flfect is a crucial isse of this field;however,only a few experimental tests on mice for wavelength selection have been reported.We addressed this ssue by low-ost,straightforward and quantitative comparisons on light dosage distribution within visible Chinese human head by Monte Carlo modeling of near infrared light propagation.Optimized selection in wavelength,beam type and size were given based on comparisons among frequently used setups(ie,wavelengths:660,810 and 980 nm;beam type:Gaussian and flat beamn;beam diameter:2,4 and 6 cm).This study provided an fficient way for guiding the optimization of LLLT setup and selection on wavelength,beam type and size for clinical brain LLLT.

Laser therapy on points of acupuncture on nerve repair

Paresthesia is the name given to a temporary or permanent sensory loss caused by several surgical procedures that affected the peripheral sensory nerve.In dentistry,common iatrogenic procedures that can lead to sensory loss include third molar removal,

Treatment effects and periodontal status of chronic periodontitis after routine Er:YAG laser-assisted therapy

BACKGROUND Routine preclinical interventions for patients with chronic periodontitis such as supragingival cleaning and subgingival curettage,establishing a balanced occlusal relationship,and irrigation with 3%hydrogen peroxide can relieve the symptoms to some extent.However,there is room for improvement in the overall effect.For example,Er:YAG lasers can quickly increase the temperature of the irradiated tissue,effectively eliminate dental plaque and calculus,reduce periodontal pockets,adjust periodontal microecology,and reduce the gingival sulcus.The content of factors in the liquid,and then achieve the purpose of treatment.AIM The aim was evaluate the effect of Er:YAG laser-assisted routine therapy on the periodontal status in chronic periodontitis.METHODS Between October 2018 and January 2020,106 patients with chronic periodontitis in our hospital were randomly assigned to either the study or control group,with 53 patients in each group.The control group underwent routine therapy,and the study group underwent Er:YAG laser therapy in addition to routine therapy.We evaluated the treatment outcome in both groups.Periodontal status was determined by clinical attachment loss(CAL),gingival index(GI),periodontal probing depth(PD),dental plaque index(PLI),and sulcular bleeding index(SBI),inflammatory factors in the gingival crevicular fluid,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-8],and colony forming units(CFUs).RESULTS Total effectiveness in the study group(94.34%)was higher than that in the control group(79.25%,P<0.05).The clinical parameters in the study group(PD,5.28±1.08 mm;CAL,4.81±0.79 mm;SBI,3.37±0.59;GI,1.38±0.40;PLI,2.05±0.65)were not significantly different from those in the control group(PD,5.51±1.14 mm;CAL,5.09±0.83 mm;SBI,3.51±0.62;GI,(1.41±0.37;PLI,1.98±0.70)before treatment(P>0.05).However,after treatment,the parameters in the study group(PD,2.97±0.38 mm;CAL,2.71±0.64 mm;SBI,2.07±0.32;GI,0.51±0.11;PLI,1.29±0.34)were lower than those in the control group(PD,3.71±0.42 mm;CAL,3.60±0.71 mm;SBI,2.80±0.44;GI,0.78±0.23;PLI,1.70±0.51)(P<0.05).Differences in crevicular TNF-α,IL-6,and IL-8 levels in the study(TNF-α,7.82±3.43 ng/mL;IL-6,11.67±2.59 ng/mL;IL-8,12.12±3.19 pg/mL)and control groups(TNF-α,9.06±3.89 ng/ml,IL-6,12.13±2.97 ng/mL,IL-8,10.99±3.30 pg/mL)before therapy(P>0.05)were not significant.Following treatment,the parameters were significantly lower in the study group(TNF-α,2.04±0.89 ng/mL;IL-6,4.60±1.26 ng/mL;IL-8,3.15±1.08 pg/mL)than in the control group(TNF-α,3.11±1.07 ng/mL;IL-6,6.25±1.41 ng/mL;IL-8,4.64±1.23 pg/mL,P<0.05).The difference in the CFU of the study group[(367.91±74.32)×104/mL and control group(371.09±80.25)×104/mL]before therapy was not significant(P>0.05).The CFU decreased in both groups following therapy,however,the CFU values were lower in the study group[(36.09±15.26)×104/mL]than in the control group[(45.89±18.08)×104/mL](P<0.05).CONCLUSION Combining Er:YAG lasers with routine measures significantly improved the overall periodontal therapy outcomes by improving periodontal status and reducing oral levels of inflammatory factors and CFUs.

Photobiomodulation with Super-Pulsed Laser Shows Efficacy for Stroke and Aphasia: Case Studies

Background: Brain disorders have become more and more common today, due to both the aging population and the ever-expanding sports community. However, a new therapeutic technology called photobiomodulation (PBM) is giving hope to thousands of individuals in need. Traumatic brain injury (TBI), dementia, post traumatic stress (PTSD) and attention deficit (ADD) disorders are in many cases quickly and safely improved by PBM. PBM employs red or near-infrared (NIR) light (600 - 1100 nm) to stimulate healing, protect tissue from dying, increase mitochondrial function, improve blood flow, and tissue oxygenation. PBM can also act to reduce edema, increase antioxidants, decrease inflammation, protect against apoptosis, and modulate the microglial activation state. All these effects can occur when light is delivered to the head, and can be beneficial in both acute and chronic brain conditions. Methods: In this case series, we used a high power, FDA-approved superpulsed laser system applied to the head to treat four chronic stroke patients. Patients received as few as three 6 - 9 minute treatments over a one-week period. The follow up time varied, but in one case was two years. Results: Patients showed significant improvement in their speech and verbal skills. Improvements were also noticed in walking ability, limb movement, less numbness, and better vision. Conclusion: The use of PBM in stroke rehabilitation deserves to be tested in controlled clinical trials, because this common condition has no approved pharmaceutical treatment at present.

Effects of Kangfuxin Solution (康复新液) Combined with Low-level Laser on Cytokines and Immune Function in Patients with Radiation-induced Oral Mucositis

Objective:To investigate the effect of Kangfuxin Solution(康复新液)combined with low-level laser therapy(LLLT)on cytokines and immune function in patients with radiation-induced oral mucositis.Methods:There were 84 nasopharyngeal carcinoma patients with oral mucositis after intensity-modulated radiation therapy(IMRT)were randomly divided into the control group(CG)and the observation group(OG),with 42 cases in each group.The CG was given LLLT,and the OG was treated with Kangfuxin Solution in addition to LLLT for 10 consecutive days.The healing time of oral mucosa,mucositis grading,oral pain scores,cytokines(interleukin-6,interleukin-1βand tumor necrosis factor-α)and T lymphocyte subsets were compared between the 2 groups before and after treatment.Results:The healing time of oral mucosa in the OG was(6.8±1.4)d,which was significantly shorter than(8.6±1.9)d in the CG(t=4.943,P<0.01).After treatment,the grading of oral mucositis in the OG was better than that in the CG,with a statistically significant difference(Z=2.942,P<0.05).The oral pain scores of the OG was lower than that in the CG at different time points after treatment,and the difference was statistically significant(t=8.207,11.017,P<0.01).After treatment,the levels of IL-6,IL-1βand TNF-αin peripheral blood of the OG were significantly lower than those in the CG(t=5.217,2.775,4.053,P<0.01).There were statistically significant differences in CD4+,CD8+and CD4+/CD8+between the OG and the CG after treatment(t=5.692,6.093,3.658,P<0.01).Conclusion:Kangfuxin Solution combined with LLLT can significantly shorten the healing time of oral mucosal,reduce the grading of oral mucositis,relieve oral pain,reduce inflammatory response and improve the immune function of patients.

Three-year follow-up of Coats disease treated with conbercept and 532-nm laser photocoagulation

BACKGROUND Coats disease is an idiopathic exudative outer retinopathy caused by abnormalretinal vascular development.AIM To evaluate the long-term outcomes of intravitreal conbercept injection with laserphotocoagulation as a treatment for Coats disease in adults.METHODS This retrospective case series study included patients diagnosed with Coatsdisease and treated with intravitreal conbercept injection and 532-nm laserphotocoagulation at the Ophthalmology Department of Shenzhen People’sHospital between January 2016 and January 2017. Best-corrected visual acuity(BCVA) measurements, noncontact tonometry, ophthalmoscopy, fundusphotography, fundus fluorescein angiography and optical coherence tomographywere performed before treatment and at 1 wk, 1 mo, 3 mo, 6 mo, 9 mo, 12 mo, 24mo and 36 mo after therapy. Best-corrected visual acuity was measured using theearly treatment of diabetic retinopathy study chart.RESULTS The study included eight eyes of 8 patients (7 men) aged 36.10 ± 6.65 years. Theaverage BCVA of the affected eye before treatment was 51.17 ± 15.15 letters(range, 28–70 letters), and the average central macular thickness was 303.30 ±107.87 μm (range, 221–673 μm). Four eyes were injected once, three were injectedtwice, and one was injected three times. Average follow-up duration was 37.33 ±2.26 mo. Average BCVA of the affected eye was 51.17 ± 15.15 letters before treatment and was increased by 13.50 ± 3.20, 16.25 ± 7.73, 18.25 ± 8.96, 18.03 ± 5.27,18.63 ± 3.35, 19.75 ± 6.96, 18.05 ± 5.36 and 17.88 ± 3.45 letters at 1 wk, 1 mo, 3 mo, 6mo, 9 mo, 12 mo, 24 mo and 36 mo after treatment, respectively (P < 0.01). Thepatients showed varying degrees of subretinal fluid resorption after treatment.None of the patients had serious complications such as increased intraocularpressure, development/progression of cataracts, endophthalmitis or retinaldetachment.CONCLUSION Intravitreal injection of conbercept combined with 532-nm laser photocoagulationmay be a feasible treatment for Coats disease in adult patients.

Efficiency and safety of laser photocoagulation with or without intravitreal ranibizumab for treatment of diabetic macular edema: a systematic review and Meta-analysis

AIM： To compare the therapeutic effect and safety of laser photocoagulation along with intravitreal ranibizumab（IVR） versus laser therapy in treatment of diabetic macular edema（DME）.METHODS： Pertinent publications were identified through comprehensive searches of Pub Med, EMBASE, Web of Science, Cochrane Library, and Clinical Trials.gov to identify randomized clinical trials（RCTs） comparing IVR＋laser to laser monotherapy in patients with DME. Therapeutic effect estimates were determined by weighted mean differences（WMD） of change from baseline in best corrected visual acuity（BCVA） and central retinal thickness（CRT） at 6, 12, or 24 mo after initial treatment, and the risk ratios（RR） for the proportions of patients with at least 10 letters of improvement or reduction at 12 mo. Data regarding major ocular and nonocular adverse events（AEs） were collected and analyzed. The Review Manager 5.3.5 was used.RESULTS： Six RCTs involving 2069 patients with DME were selected for this Meta-analysis. The results showed that IVR＋laser significantly improved BCVA compared with laser at 6mo（WMD： 6.57; 95% CI： 4.37-8.77; P〈0.00001）, 12mo（WMD： 5.46; 95% CI： 4.35-6.58; P〈0.00001）, and 24mo（WMD： 3.42; 95% CI： 0.84-5.99; P=0.009） in patients with DME. IVR＋laser was superior to laser in reducing CRT at 12 mo from baseline with statistical significance（WMD：-63.46; 95% CI：-101.19 to-25.73; P=0.001）. The pooled RR results showed that the proportions of patients with at least 10 letters of improvement or reduction were in favor of IVR＋laser arms compared with laser（RR： 2.13; 95% CI： 1.77-2.57; P〈0.00001 and RR： 0.37; 95% CI： 0.22-0.62; P=0.0002, respectively）. As for AEs, the pooled results showed that a significantly higher proportion ofpatients suffering from conjunctival hemorrhage（study eye） and diabetic retinal edema（fellow eye） in IVR＋laser group compared to laser group（RR： 3.29; 95% CI： 1.53-7.09; P=0.002 and RR： 3.02; 95% CI： 1.24-7.32; P=0.01, respectively）. The incidence of other ocular and nonocular AEs considered in this Meta-analysis had no statistical difference between IVR＋laser and laser alone.CONCLUSION： The results of our analysis show that IVR＋laser has better availability in functional（improving BCVA） and anatomic（reducing CRT） outcomes than laser monotherapy for the treatment of DME. However, the patients who received the treatment of IVR＋laser may get a higher risk of suffering from conjunctival hemorrhage（study eye） and diabetic retinal edema（fellow eye）.

Blue LED as a new treatment to vaginal stenosis due pelvic radiotherapy:Two case reports

BACKGROUND Currently,the advancement cancer treatment technology improves overall survival,however,adverse events are still a challenge for health professional.Genitourinary syndrome of menopause and vaginal stenosis are conditions that impact the quality of life of patients undergoing radiotherapy.We present two such cases in patients with previous cervical and endometrial cancer.These conditions were handled with an innovative method using an energy-based device with blue light emitting diode for concomitant vaginal and vulvar irradiation.Positive impact in clinical findings,cytologic changes,and referred symptoms were documented.CASE SUMMARY One patient diagnosed with vaginal severe vaginal stenosis with previous cervix cancer treatment and other patient diagnosed with mild stenosis with severe dyspareunia and recent endometrium cancer treatment were considered for vulvovaginal treatment with weekly blue led device and closely evaluated with repeated validated questionnaires and cytological samples.CONCLUSION This innovative technique showed an improvement in all areas of the examiner's criteria,the cytological criteria,and most bothered symptoms.

Effects of RFTVR and CO2 laser on symptoms improvement, QOL and vas of patients with early laryngeal cancer

Objective: To study the effect of RFTVR and CO2 laser on the improvement of symptoms, QOL and vas of patients with early laryngeal cancer. Methods: In this study, 120 patients with laryngeal cancer diagnosed and treated from January 2015 to December 2016 were taken as research objects. All patients were randomly divided into observation group and control group, 60 patients in each group. Patients in observation group were treated with RFTVR, and patients in control group were treated with new-type fiber-optic CO2 laser. The patients in the two groups were treated with cisplatin injection. The differences of perioperative indexes, swallowing function, pronunciation function, survival period, QOL score and VAS score between the two groups were compared. Results: There was no significant difference in the amount of intraoperative bleeding, operation time and hospitalization time between the two groups (P > 0.05);the correct swallowing of the observation group was significantly higher than that of the control group. After treatment, jitter, shimmer and HNR of the two groups were significantly improved, and jitter and shimmer of the observation group were significantly lower than that of the control group, and HNR was significantly higher than that of the control group (P < 0.05) The QOL score and VAS score of the two groups were significantly improved, and the QOL score of the observation group was significantly higher than that of the control group and the VAS score was significantly lower than that of the control group (P < 0.05);the total survival period and tumor free survival period of the observation group were significantly higher than that of the control group. Conclusion: Compared with CO2 laser treatment, the swallowing function and voice function of patients treated by low temperature plasma radiofrequency ablation were significantly improved, and the life quality of patients was significantly improved by prolonging the survival period of patients..

Photobiomodulation therapy for osteoarthritis: Mechanisms of action

Photobiomodulation(PBM)is a non-invasive therapeutic modality with demonstrated effects in many fields related to regenerative medicine.In the field of orthopedics,in particular,PBM at various wavelengths has demonstrated the capacity to trigger multiple biological effects associated with protective mechanisms in musculoskeletal tissues.The articles cited in this review show that devices operating close to or within the near infrared range at low intensities can provoke responses which favor the shift in the predominant catabolic microenvironment typically seen in degenerative joint diseases,especially osteoarthritis(OA).These responses include proliferation,differentiation and expression of proteins associated with stable cell cycles.Additionally,PBM can also modulate oxidative stress,inflammation and pain by exerting regulatory effects on immune cells and blocking the transmission of pain through sensory neuron fibers,without adverse events.Collectively,these effects are essential in order to control the progression of OA,which is in part attributed to exacerbated inflammation and degradative enzymatic reactions which gradually contribute to the destruction of joint tissues.PBM may offer medical experts ease of application,financial viability,efficacy and lack of serious adverse events.Therefore,it may prove to be a suitable ally in the management of mild to moderate degrees of OA.This review explores and discusses the principal biological mechanisms of PBM and how the produced effects may contribute to the amelioration of osteoarthritic progression.Literature was reviewed using PubMed and Google Scholar in order to find studies describing the mechanisms of PBM.The investigation included a combination of nomenclature such as:“photobiomodulation”,“phototherapy”,“laser therapy”,“PBM”,“osteoarthritis”,low level light therapy”,“inflammation”and“cartilage”.We considered only articles written in English,with access to the full text.

Successful Treatment of Mutinucleate Cell Angiohistiocytoma with Nd:YAG Laser

A 50-year-old man had noticed the gradual appearance of asymptomatic skin lesions on the dorsal aspects of the hands during the last 3 years. Physical examination revealed clusters of multiple purplish dome-shaped infiltrated papules. Histopathological examination was compatible mutinucleate cell angiohistiocytoma. We treated him with 10,464 nm Nd:YAG laser, after the second session, some of the lesions had disappeared completely while the rest has gained substantial improvement. There were no adverse reactions and no recurrence after two years of follow-up. MCAH is a rare vascular fibrohistiocytic proliferation. No standard of care exists. We believe that Nd:YAG laser should be considered the treatment of choice.

Lasers in gastroenterology

INTRODUCTIONEndoscopy has revolutionised our management of many gastrointestinal disorders over the past 30 years .We are increasingly able to diagnose gastrointestinal (GI) tumors at an early stage,and endoscopic therapy has made a difference to the outcome of GI haemorrhage. We still rely on surgery for cure of cancer of cancer but as diagnostic techniques improve the goal of minimally invasive diagnosis and therapy appears ever more attainable diagnosis and therapy appears vevr more attainable . As populations get older ,it is also increasingly desirable .Laser light can be used for both diagnosis and therapy in the gut .This article reviews the value of lasers in these areas .

Photobiomodulation provides neuroprotection through regulating mitochondrial fission imbalance in the subacute phase of spinal cord injury

Increasing evidence indicates that mitochonarial lission imbalance plays an important role in derayed neuronal cell death. Our previous study round that photo biomodulation improved the motor function of rats with spinal cord injury.However,the precise mechanism remains unclear.To investigate the effect of photo biomodulation on mitochondrial fission imbalance after spinal cord injury,in this study,we treated rat models of spinal co rd injury with 60-minute photo biomodulation(810 nm,150 mW) every day for 14 consecutive days.Transmission electron microscopy results confirmed the swollen and fragmented alte rations of mitochondrial morphology in neurons in acute(1 day) and subacute(7 and 14 days) phases.Photo biomodulation alleviated mitochondrial fission imbalance in spinal cord tissue in the subacute phase,reduced neuronal cell death,and improved rat posterior limb motor function in a time-dependent manner.These findings suggest that photobiomodulation targets neuronal mitochondria,alleviates mitochondrial fission imbalance-induced neuronal apoptosis,and thereby promotes the motor function recovery of rats with spinal cord injury.

Potential targets and mechanisms of photobiomodulation for spinal cord injury

As a classic noninvasive physiotherapy,photobiomodulation,also known as low-level laser therapy,is widely used for the treatment of many diseases and has anti-inflammatory and tissue repair effects.Photobiomodulation has been shown to promote spinal cord injury repair.In our previous study,we found that 810 nm low-level laser therapy reduced the M1 polarization of macrophages and promoted motor function recovery.However,the mechanism underlying this inhibitory effect is not clear.In recent years,transcriptome sequencing analysis has played a critical role in elucidating the progression of diseases.Therefore,in this study,we performed M1 polarization on induced mouse bone marrow macrophages and applied low-level laser therapy.Our sequencing results showed the differential gene expression profile of photobiomodulation regulating macrophage polarization.We analyzed these genes using gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses.Networks of protein-protein interactions and competing RNA endogenous networks were constructed.We found that photobiomodulation inhibited STAT3 expression through increasing the expression of miR-330-5p,and that miR-330-5p binding to STAT3 inhibited STAT3 expression.Inducible nitric oxide synthase showed trends in changes similar to the changes in STAT3 expression.Finally,we treated a mouse model of spinal cord injury using photobiomodulation and confirmed that photobiomodulation reduced inducible nitric oxide synthase and STAT3 expression and promoted motor function recovery in spinal cord injury mice.These findings suggest that STAT3 may be a potential target of photobiomodulation,and the miR-330-5p/STAT3 pathway is a possible mechanism by which photobiomodulation has its biological effects.