• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.1
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• pp.7-10
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• 2008

The early glottic cancers are traditionally treated by radiotherapy or endoscopic surgery. The excellent effectiveness of both treatment modalities for local control, larynx preservation, and disease specific death is similar. Therefore, functional voice outcome after treatment is one of the most important factors in the choice of treatment for early glottic cancer. To assess the functional outcomes and compare the voice quality in patients with early glottic cancer treated with curative intent with radiotherapy or laser cordectomy, we performed literature review. Most studies showed that the voice quality after radiation therapy is slightly better than that after laser cordectomy. Subanalysis according to types of laser cordectomy, however, indicates that voice quality depends on type of laser cordectomy. Especially, type I or type II laser cordectomy might be superior to other types of laser cordectomy and radiation therapy. We conclude that the laser cordectomy is a good surgical alternative for properly selected early glottic cancer including professional voice users.

• Journal of Biomedical Engineering Research
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• v.30 no.1
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• pp.18-22
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• 2009

Laser has been widely used in various fields of medicine. Recently, noninvasive low-level laser therapeutic medical devices have been introduced in market. However, low-level laser cannot deliver enough photon density to expect positive therapeutic results in deep tissue layer due to the light scattering property in tissue. In order to overcome the limitation, this study was aimed to develop a negative pressure applied low-level laser probe to optimize laser transmission pattern and therefore, to improve photon density in soft tissue. In order to evaluate the possibility of clinical application of the developed laser probe, ex-vivo experiments were performed with porcine skin samples and laser transmissions were quantitatively measured as a function of tissue compression. The laser probe has an air suction hole to apply negative pressure to skin, a transparent plastic body to observe variations of tissue, and a small metallic optical fiber guide to support the optical fiber when negative pressure was applied. By applying negative pressure to the laser probe, the porcine skin under the metallic optical fiber guide is compressed down and, at the same time, low-level laser is emitted into the skin. Finally, the diffusion images of laser in the sample were acquired by a CCD camera and analyzed. Compared to the peak intensity without the compression, the peak intensity of laser increased about $2{\sim}2.5$ times and FWHM decreased about $1.67{\sim}2.85$ times. In addition, the laser peak intensity was positively and linearly increased as a function of compression. In conclusion, we verified that the developed low-level laser probe can control the photon density in tissue by applying compression, and therefore, its potential for clinical applications.

• Imaging Science in Dentistry
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• v.51 no.4
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• pp.429-438
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• 2021

Purpose: This study investigated the accuracy of laser-scanned models and 3-dimensional(3D) rendered cone-beam computed tomography (CBCT) compared to the gold standard (plaster casts) for linear measurements on dental arches. Materials and Methods: CBCT scans and plaster models from 30 patients were retrieved. Plaster models were scanned by an Emerald laser scanner (Planmeca, Helsinki, Finland). Sixteen different measurements, encompassing the mesiodistal width of teeth and both arches' length and width, were calculated using various landmarks. Linear measurements were made on laser-scanned models using Autodesk Meshmixer software v. 3.0 (Autodesk, Mill Valley, CA, USA), on 3D-rendered CBCT models using OnDemand 3D v. 1.0 (Cybermed, Seoul, Korea) and on plaster casts by a digital caliper. Descriptive statistics, the paired t-test, and intra- and inter-class correlation coefficients were used to analyze the data. Results: There were statistically significant differences between some measurements on plaster casts and laser-scanned or 3D-rendered CBCT models (P<0.05). Molar mesiodistal width and mandibular anterior arch width deviated significantly different from the gold standard in both methods. The largest mean differences of laser-scanned and 3D-rendered CBCT models compared to the gold standard were 0.12±0.23 mm and 0.42±0.53 mm, respectively. Most of the mean differences were not clinically significant. The intra- and inter-class correlation results were acceptable for all measurements(>0.830) and between observers(>0.801). Conclusion: The 3D-rendered CBCT images and laser-scanned models were useful and accurate alternatives to conventional plaster models. They could be used for clinical purposes in orthodontics and prostheses.

• 대한두경부종양학회:학술대회논문집
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• 2003.11a
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• pp.221-221
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• 2003

• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.148-152
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• 2011

Objective: Laser-assisted intracytoplasmic sperm injection (LA-ICSI), also known as micro-opening or thinning of the zona pellucida (ZP) prior to ICSI, may help to reduce mechanical damage to the oocyte during the procedure. The aim of the present study was to evaluate and analyze the efficacy of our institutional LA-ICSI program, which features laser-assisted ZP thinning prior to ICSI, in comparison with conventional ICSI (C-ICSI), performed on patients with different clinical characteristics. Methods: Patients undergoing a total of 212 ICSI cycles were randomly divided into an LA-ICSI group (106 cycles) and a conventional ICSI group (106 cycles). To reduce tissue damage, we thinned the ZP by approximately 70%, using a laser, before ICSI. Patients thus treated formed the LAICSI group. Comparisons included the morphological quality of transferred embryos, blastocyst development of the remaining embryos, and clinical pregnancy, in terms of ICSI method and patient characteristics. Results: Fertilization, development of remaining embryos, and pregnancy rate were significantly higher in the LA-ICSI group compared with the C-ICSI group. Fertilization, embryonic development, and the pregnancy rate were all improved in younger patients (<38 years of age) and in those who underwent a low number of IVF-ET attempts (<3 trials). In addition, the pregnancy rate was increased in older patients. Conclusion: LA-ICSI may be useful in improving the chance of pregnancy in all ICSI patients.

• Korean Journal of Bronchoesophagology
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• v.4 no.2
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• pp.159-164
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• 1998

The developmental and subsequent addition of laser technology to existing surgical techniques offered new and exciting Possibilities for improving traditional endoscopic operations and expanding the scope of the specialty of otolaryngology-head and neck surgery. Lasers were found to be Precise, but potentially dangerous, surgical instruments whose use was associated with certain distinct and unprecedented advantages, but also with many unique and potentially serious, and sometimes catastrophic complications. The Purpose of this study was to evaluate the of elation technique of $CO_2$laser, kinds of anesthesia, equipments of operating room, and education of medical staff. Four hundreds 4 cases of $CO_2$laser laryngeal microsurgery were reviewed for the safety of $CO_2$laser in laryngeal microsurgery. Vocal polyp (46,3%) was the most common pathology in our cases. The others were vocal nodule, Reinke`s edema, epiglottic cyst, laryngeal granuloma, laryngeal papilloma, intracordal cysts, laryngeal tuberculosis, laryngeal web, laryngotracheal stenosis, and laryngeal cancer. Following complete equipment controls, treatment area controls, maintenance, service and procedural controls, personel protective equipment, and warning signs, no complications were found in our cases. In conclusion, laryngeal microsurgery with $CO_2$laser could be done safely without complication if complete preoperative preparation and education of medical staff preceded.

• Medical Lasers
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• v.9 no.2
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• pp.190-193
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• 2020

A 45-year-old Korean male with laryngotracheal papilloma was treated using a 532-nm diode laser at six watts with a pulse width of 25 milliseconds. Two months after the laser treatment, the resected region was well-healed without significant scar contracture. This outcome suggests that a 532-nm diode laser can be a safe and effective treatment for laryngotracheal papilloma.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.151-152
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• 2008

Laser has been applied in various diagnostic and therapeutic medical fields. For last few decades, medical low-level laser devices have been introduced in market, but they have limitations which cannot convey enough energy to deep layer of tissues for diagnostic or therapeutic purposes. To address the issue, there have been many studies of using physical and chemical methods; it is one of ways to apply negative or positive pressure to tissue. However, it is hard to apply desired pressure on tissues continuously when practical laser devices arc used. In this study, we introduce a low-level laser probe which allows maintain pressure on skin tissue. Consequently, we are confident that the pressure probe for low-level laser treatment should be a useful tool in order to deliver sufficient energy for practical uses.

• Medical Lasers
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• v.9 no.2
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• pp.134-141
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• 2020

The use of stem cell therapy to treat various diseases has become a promising approach. The ability of stem cells to self-renew and differentiate can contribute significantly to the success of regenerative medical treatments. In line with these expectations, there is a great need for an efficient research methodology to differentiate stem cells into their specific targets. Photobiomodulation (PBM), formerly known as low-level laser therapy (LLLT), is a relatively non-invasive technique that has a therapeutic effect on damaged tissue or cells. Recent advances in adapting PBM to stem cell therapy showed that stem cells and progenitor cells respond favorably to light. PBM stimulates different types of stem cells to enhance their migration, proliferation, and differentiation in vitro and in vivo. This review summarizes the effects of PBM on targeted differentiation across multiple stem cell lineages. The analytical expertise gained can help better understand the current state and the latest findings in PBM and stem cell therapy.

• The Journal of Korean Medicine
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• v.22 no.3
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• pp.11-20
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• 2001

Objective: As early as 1967, professor Endre Mester's group published the first scientific report concerning the effects of low level laser therapy (LLLT) on the skin of rats. After that, there have been some two thousand research reports from many countries in which the biological effects of low level lasers have been demonstrated. We reviewed some theses about LLLT published in Korea recently, and we make a proposal concerning the new method of study using LLLT in Oriental Medicine. Methods: We have selected 12 medical theses about low level laser therapy published in Korean Oriental Medicine journals recently, reviewed them, and investigated their methods. Results and Conclusion: There were several clinical studies in Korea about hyperlipidemia, hypercholesteremia, hyperfibrinogenemia, hyperlipoproteinemia, headache, dizziness, stroke, pain and numbness published from 1996 to 2000 using LLLT. The number of theses of good quality is showing a tendency to increase, recently. Sooner or later LLLT will be a very useful treatment and we believe that it will be an alternative useful method in Oriental Medical fields. There have been some negative public opinions about LLLT voiced in the Korean Oriental Medical society recently, but we expect a positive re-evaluation of this new treatment within Oriental Medicine in the near future.