• Korean Journal of Acupuncture
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• v.28 no.2
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• pp.37-47
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• 2011

Objectives : We have studied the effects of GaAlAs (808 nm) low level laser therapy (LLLT) and acupuncture at BL40 on neuropathic pain in rats induced by lumbar spinal nerve 5 ligation. Methods : To produce the model of neuropathic pain, under isoflurane 2.5% anesthesia, the lumbar spinal nerve 5 was ligated by 6-0 silk thread. After neuropathic surgery, we examined if the animals exhibited the behavioral sign of allodynia. The allodynia was assessed by stimulating the medial malleolus with von Frey filament and acetone. Three weeks after the neuropathic surgery, GaAlAs (808 nm) low level laser and acupuncture was inserted at BL40 once a day for 6 days. We examined the withdrawal response of neuropathic rats' legs by von Frey filament and acetone stimulation. And also the author examined c-Fos, nociceptin and nociceptin receptor in the midbrain central gray of neuropathic rats. Results : The GaAlAs (808 nm) low level laser therapy and acupuncture at BL40 decreased the withdrawal response of mechanical allodynia that assessed with von Frey filament in LLLT group on 5 and 6 times and with acetone in AT group and LLLT on 6times. The LLLT and acupuncture at BL40 decreased the c-Fos protein expression in AT and LLLT groups. The 808 nm LLLT and acupuncture at BL40 decreased the nociceptin protein and nociceptin receptor protein in LLLT group. Conclusions : We have noticed that GaAlAs (808 nm) LLLT and acupuncture at BL40 decreased mechanical allodynia in the model of neuropathic pain. c-Fos, nociceptin and nociceptin receptor expression in the central gray of that group was also decreased. This study can be used as a basic resource on a study and a treatment of pain.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.77-83
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• 2010

Purpose: The aim of this study was to do numerical analysis of the wavelength dependence in low level laser therapy (LLLT) using a finite element method (FEM). Methods: Numerical analysis of heat transfer based on a Pennes' bioheat equation was performed to assess the wavelength dependence of effects of LLLT in a single layer and in multilayered tissue that consists of skin, fat and muscle. The three different wavelengths selected, 660 nm, 830 nm and 980 nm, were ones that are frequently used in clinic settings for the therapy of musculoskeletal disorders. Laser parameters were set to the power density of 35.7 W/$cm^2$, a spot diameter of 0.06 cm, and a laser exposure time of 50 seconds for all wavelengths. Results: Temperature changes in tissue based on a heat transfer equation using a finite element method were simulated and were dominantly dependent upon the absorption coefficient of each tissue layer. In the analysis of a single tissue layer, heat generation by fixed laser exposure at each wavelength had a similar pattern for increasing temperature in both skin and fat (980 nm > 660 nm > 830 nm), but in the muscle layer 660nm generated the most heat (660 nm ${\gg}$ 980 nm > 830 nm). The heat generation in multilayered tissue versus penetration depth was shown that the temperature of 660 nm wavelength was higher than those of 830 nm and 980 nm Conclusion: Numerical analysis of heat transfer versus penetration depth using a finite element method showed that the greatest amount of heat generation is seen in multilayered tissue at = 660 nm. Numerical analysis of heat transfer may help lend insight into thermal events occurring inside tissue layers during low level laser therapy.

• The Korean Journal of Pain
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• v.37 no.4
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• pp.310-319
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• 2024

Background: This study aimed to investigate the analgesic and preventive effect of low-level laser therapy (LLLT) on the incisional pain model and spinal nerve ligation (SNL) model in rats and identify the possible mechanisms of action. Methods: Male Sprague-Dawley rats were used, divided into different treatment groups. The single application group received LLLT before or after skin incision or SNL. The consecutive application group received LLLT for six consecutive days post-incision, three days pre-incision, or three consecutive days pre-SNL. The control group underwent skin incision or SNL without LLLT. The von Frey test was used to quantify the pain associated with mechanical allodynia. Pro-inflammatory cytokine level and alterations in nerve growth factor (NGF) expression were measured by using ELISA and immunohistochemistry, respectively in the skin, muscle of the paw, and spinal cord dorsal horn (SCDH). Results: In the incisional pain model, LLLT showed significant analgesic and preventive effect. LLLT ameliorated SNL-induced mechanical allodynia but LLLT had no preventive effect. LLLT decreased interleukin-1β (IL-1β) expression levels in the skin, muscle, and SCDH and reduced the optical density of skin and spinal cord NGF in the incisional pain model. Conclusions: LLLT alleviated incisional pain and neuropathic pain caused by SNL in rats, and reduced the levels of IL-1β and NGF in the peripheral tissue and SCDH in the incisional pain model. LLLT might be effective in patients with post-operative pain and peripheral neuropathic pain.

• Journal of Dental Anesthesia and Pain Medicine
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• v.19 no.5
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• pp.289-294
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• 2019

Background: Pain, limitations in opening, asymmetrical jaw movements, and temporomandibular joint (TMJ) sounds are the most common findings in temporomandibular joint disorders (TMDs), which causes excruciating pain, inflammation of the surrounding muscles, posterior fibers, and synovial fluid. This study aimed to evaluate and compare the effects of ultrasound heat therapy and low-level laser therapy (LLLT) in reducing TMD-related pain. Methods: This prospective study included 42 patients (age range, 25-45 years), who were divided into two groups of 21 patients each. All patients were prescribed a non-steroidal anti-inflammatory drug (NSAID) twice a day for 5 days for temporary relief of pain prior to the commencement of treatment. Patients were kept on a soft diet and asked to restrict mouth opening during the same period. Fifteen sessions of LLLT (Group A) or ultrasound therapy (Group B) were administered to the affected side. Results: Post-therapy, the mean visual analog scale score for group A and group B was 4.81 (2.01) and 6.19 (1.20), respectively; the difference was statistically significant and favoring the LLLT group. Similarly, the mean mouth opening for group A and group B was 3.99 (0.40) and 3.65 (0.41), respectively; the difference was statistically significant and favoring the LLLT group. Conclusion: Our study recommends LLLT for treating TMD-related pain with no underlying bony pathology.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.1
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• pp.2-8
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• 2016

Objectives: The purpose of this study was to investigate the effects of low-level laser therapy (LLLT) with a diode gallium-aluminum-arsenide (Ga-Al-As) low-level laser device on the healing and attachment of titanium implants in bone. Materials and Methods: Thirteen New Zealand white male rabbits weighing $3.0{\pm}0.5kg$ were used for this study. Dental titanium implants (3.75 mm in diameter and 8.5 mm in length, US II RBM plus fixture; Osstem, Seoul, Korea) were implanted into both femurs of each rabbit. The rabbits were randomly divided into a LLLT group and a control group. The LLLT was initiated immediately after surgery and then repeated daily for 7 consecutive days in the LLLT group. Six weeks and 12 weeks after implantation, we evaluated and compared the osseointegration of the LLLT group and control group, using histomorphometric analysis, removal torque testing, and resonance frequency analysis (RFA). The results were statistically significant when the level of probability was 0.05 or less based on a non-parametric Mann-Whitney U-test. Results: The implant survival rate was about 96%. Histologically and histomorphometrically, we observed that the titanium implants were more strongly attached in LLLT group than in control group. However, there was no significant difference between the LLLT group and control group in removal torque or RFA. Conclusion: Histologically, LLLT might promote cell-level osseointegration of titanium implants, but there was no statistically significant effects.

• The korean journal of orthodontics
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• v.48 no.2
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• pp.90-97
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• 2018

Objective: The aim of this study was to assess the analgesic effect of a single application of low-level laser therapy (LLLT) on spontaneous pain and pain on chewing after placement of initial archwires. Methods: Forty-two patients (26 women, 16 men) were randomly recruited for this split-mouth randomized clinical trial. Each patient received super-elastic nickel-titanium (NiTi) initial archwires (0.012, 0.014, 0.016, and 0.018-inch [in]) in the maxilla for leveling and alignment for an interval of 4 weeks between archwires. One side of the mouth was randomly designated as experimental, while the other side served as placebo. After insertion of each archwire, the experimental side was irradiated with a diode laser for 3 seconds each on 5 points facially and palatally per tooth, from the central incisor to first molar. On the placebo side, the laser device was held the same way but without laser application. A numerical rating scale was used to assess the intensity of spontaneous and masticatory pain for the following 7 days. The Mann-Whitney U test was used to compare pain scores between sides. Results: Patients in the LLLT group exhibited significantly lower mean scores for spontaneous pain after insertion of the initial two archwires (0.012-in and 0.014-in NiTi; p < 0.05), while there was no significant difference for 0.016-in and 0.018-in wires between the LLLT and placebo groups. LLLT significantly reduced chewing pain scores (p < 0.05) for all archwires. Conclusions: A single dose of LLLT considerably lessened postoperative pain accompanying the placement of super-elastic NiTi wires for initial alignment and leveling.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.29 no.4
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• pp.182-188
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• 2016

Objectives : The purpose of this study is to report the effect of low level laser therapy and acupuncture on hair loss. Methods : The patient with alopecia caused by bed sore and alopecia areata was treated with 29 times of laser therapy, acupuncture and took herbal medicine during about 3 months. The treatment effect was evaluated by standardized photography. Results : Hair loss had shown a marked improvement. Entire scalp had been replaced with new hairs. Conclusions : LLLT(low level laser therapy) is effective method for treating alopecia. It can shorten the length of treatment of alopecia.

• Korean Journal of Acupuncture
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• v.22 no.2
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• pp.163-181
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• 2005

Objective: The purpose of this study is to review research papers on low level laser therapy (LLLT) and to improve the knowledge of LLLT field. Methods: For introduction, laser characteristics, including wavelength, medium, beam size, power, and unit power were explained. In order to understand LLLT, tissue optics and light-biomatter interaction were briefly mentioned. We reviewed 21 Korean papers on laser acupuncture and LLLT on the viewpoint of laser apparatus. Results and Conclusion: We found that the description of laser apparatus employed for LLLT experiments were not fully written. Laser wavelength and power which are the most crucial parameters, were omitted in several papers. No paper had information on beam size. In order to have high efficacy, laser should be used with proper laser parameters. Conditions of irradiation area or acupoints should be considered too. Some future technology on laser acupuncture were mentioned.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.3
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• pp.193-206
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• 2009

Objectives The purpose of this study is to evaluate the effects of Low Level Laser Therapy on Atopic dermatitis symptoms. Methods 19 patients (7 men, 12 women) were involved in this study. The intensity of SCORAD index (Erythema/darkening, Edema/papulation, Oozing/crust, Excoriation, Lichenification/prurigo, Dryness) and the symptom of SCORAD index (Pruritus) in two regions were measured. One region was treated by LLLT, the other region was not treated. Then a comparative study of index score of two regions was analyzed. Results After treatment, there were statistically significant differences in Edema/papulation, Excoriation (p<0.001), Oozing/crust (p<0.01), and Pruritus(p<0.05) index. Conclusions Based on the results, we concluded that LLLT is an effective in the treatment of atopic dermatitis. Also, further controlled studies with clinical cases of appropriate treatment time, wavelength, and intervals are needed.

• International Journal of Contents
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• v.7 no.2
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• pp.59-63
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• 2011

The aim of our study was to evaluate the immediate effects of an 830-nm Aluminium gallium arsenide (GaAlAs) laser, by examining the changes, in pressure-pain threshold (PPT) and tenderness at 3 kg of the myofascial trigger point (MTrP) of the upper trapezius muscle in visual display terminal (VDT) workers in comparison with placebo treatment. Thirty VDT workers (13 males, 17 females) with complaints of upper trapezius muscle were recruited. All participants were given either active GaAlAs laser (830 nm wavelength, 450 mW, 9 J at point) or placebo GaAlAs laser, according to the double-blinded and placebo-controlled trial. Both active and placebo low-level laser therapy (LLLT) treatments showed no significant effect on PPT and tenderness at 3 kg. These results suggest that a higher dosage may be necessary to produce immediate effects when applying LLLT to the MTrP of relatively large muscles such as the upper trapezius muscle.