• Journal of Dental Anesthesia and Pain Medicine
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• 제19권5호
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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.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.41.1-41.11
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• 2020

Background: Orthognathic surgery such as bilateral sagittal split ramus osteotomy (BSSRO) for the treatment of mandibular deformities is one of the most common procedures in maxillofacial operations that may lead to neurosensory disturbance. In this study, we aimed to evaluate the effectiveness of low-level laser therapy (LLLT) on augmenting recovery of neurosensory disturbance of inferior alveolar nerve (IAN) in patients who underwent BSSRO surgery. Methods: A comprehensive literature search was conducted by two independent authors in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Embase, and Google Scholar electronic databases. Besides, a manual search of all textbooks and relevant articles were conducted. Searches took place in August 2020 and were limited to published and peer-reviewed articles from 2000 to 2020. All analysis was performed using the comprehensive meta-analysis (CMA) and the STATA MP (version:16) software. The weighted mean difference (WMD) using the inverse variance method and the standard mean difference (SMD) was considered for continuous variables. Results: Seventy-four papers were retrieved after removing duplicate studies and finally, eight studies were assessed for qualitative synthesis and five for meta-analysis. Totally, 94 patients were included in the meta-analysis. Based on the meta-analysis, it was shown that LLLT was not effective in a short interval (0 to 48 h) after surgery, but in a period of more than 1 month after surgery, the positive results of treatment can be observed strikingly. Also, LLLT side/group showed no significant difference in some aspects of neurosensory recovery such as thermal sensation compared to the placebo side/group. Conclusions: The meta-analysis of randomized controlled trials revealed that LLLT generally improves IAN sensory disturbance caused by BSSRO. Further high-quality clinical trials with longer follow-up periods and larger sample sizes are recommended.

• Journal of Oral Medicine and Pain
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• 제36권4호
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• pp.215-224
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• 2011

본 연구의 목적은 과민치아에 904 nm GaAs 다이오드 레이저를 조사하여 치료효과를 연구하여 과민 치아의 치료에 이러한 저수준 레이저 요법을 임상적으로 사용할 수 있는지 가능성을 파악하는 데 있다. 단국대학교 치과대학 부속치과병원 안면 동통 구강내과에 내원한 환자를 대상으로 하였으며, 각 환자는 치경부에 사아질이 노출된 치아가 적어도 좌우로 2개 이상의 짝이 되는 치아를 소유하였다. 본 연구에 사용된 치아는 모두 50 개로써 실험군 25개, 대조군 25 이었다. Tactile test, cold(ice stick) test, electrical pulp test 를 실험전, 실험 1주후, 2주후, 3주후, 4주후 모두 5회 시행하였다. 레이저조사는 첫방문시, 1주후, 2주후, 3주후 등 4회하되 모두 세가지 검사를 마친 후 시행하였다. 전기치수 검사 외 Tactile test와 cold test는 주관적 평가인 visual analogue scale을 사용하였다. 실험 결과, Tactile test에서 VAS 수치는 시간 경과에 따라 유의하게 감소하였으나 실험군과 대조군간에는 유의한 차이가 없었다. 전기치수 검사에서는 실험군의 과민도가 대조군에 비해 유의하게 높았으나 (높은 역치를 의미) 시간 경과시 유의한 변화는 볼 수 없었다. 온도 (cold) 검사에서는 레이저 조사후 실험군과 대조군 간의 차이뿐 만 아니라 시간 경과 시에도 유의하게 감소하였다. 이러한 결과를 보아 904 nm GaAs 레이저는 과민치아의 치료에 비가역적인 방법으로서 효과적으로 사용할 수 있으리라 사료된다.

• 대한치과교정학회지
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• 제52권6호
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• pp.399-411
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• 2022

Objective: The objective of this randomized clinical trial was to study the skeletal and dental effects of low-level laser therapy (LLLT) along with a miniscrew-assisted expander (Hyrax) after six months of retention. Methods: After sequence generation, concealed allocation, and implementation, 24 female patients were randomly divided (1:1) into two-groups: bone-borne rapid palatal expansion (BBE) without LLLT (n = 12) and BBE with LLLT (n = 12). Eligibility criteria included female patients aged 10-13 years old with bilateral posterior crossbites. Intraoral and extraoral photographs, cone-beam computed tomography images, and digital study models were obtained before expansion and six months after retention. The 7 mm Hyrax appliance was anchored to four palatal mini-screws, which were activated twice daily for 15 days, then locked and kept in place as a retainer. LLLT was performed in the laser group during expansion and retention, according to the guidelines provided. Results: The records of 24 patients were analyzed. According to the post-retention measurements, both groups showed a significant increase in nasal and maxillary widths and total facial height. In the laser group, the Sella-Nasion-Point A and Point A-Nasion-Point B angles and the interpremolar apical distance were significantly increased. Conclusions: Within the limitations of this study, the results suggest that the parameters and protocol of LLLT do not clinically affect the efficiency of BBE in prepubertal and pubertal patients.

• Journal of Acupuncture Research
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• 제26권6호
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• pp.21-30
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• 2009

Objectives : Being introduced in the 1980s, laser acupuncture studies have been steadily carried on such as its thermal effects on human body. However, the mechanisms of effect are not yet clearly explained. Generally, laser acupuncture could be favorable for pediatric patients or people under special conditions (hemophilia, needle-phobia, pathogen-carriers, etc.) because of lower risk of infection, bleeding, pain or fainting. But there are still problems for using laser acupuncture equivalently as the traditional metal needle. The goal of this study is to review the fundamentals, history and present trend of laser acupuncture study, and to suggest how to develop laser acupuncture as an oriental medical device. Method : We performed literature search using PubMed(http://www.ncbi.nlm.nih.gov/pubmed) and Scopus(http://www.scopus.com). Search conditions are laser acupuncture, laser needle, LLLT(as title or abstract) or Litscher G(as author). Main target studies are physical fundamentals, clinical trials, physiological results and device proposals. Results : Many research have shown the similarities of laser acupuncture and traditional metal acupuncture and have reported clinical and physiological effects of laser acupuncture. But, still laser acupuncture is not widely used in Korea due to high-cost of equipments and the lack of clear understanding of laser devices. Additionally, there are still challenges in standardization and device development. Conclusions : Frequencies, laser modes, waveguides, adaptor types, polarization and signal modulations are suggested as future study subjects on laser acupuncture. More various studies and efforts for device development have to be performed to provide oriental medical doctors with evidence based confidence about usage of laser acupuncture.

• Journal of Oral Medicine and Pain
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• 제17권2호
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• pp.129-149
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• 1992

In order to verify the acceleration effect of low level laser (LLL) on oral mucosal wound healing process at cell biological level, the author studied growth pattern and ultrastructure in human gingival fibroblasts flashed by GaAlAs LLL-830 nm, 15mW for 10 minutes/flash one to three times at interval of 3-4 days through the evaluation of cell growth rate, protein conent/cell, DNA content/cell and ultrastructural changes for 14 days. The results were as follows : 1. The growth rate in gingival fibloblasts treated by LLL showed 4 orderly stages-decreasing stage after LLL treatment, acute increasing stage 3 days after LLL treatment, restring stage and recovering stage. 2. The effect of multiple flashes on LLL at interval of 3 days more or less was not proportional to times of flash on acceleration of growth in gingival fibroblasts. 3. The total protein content per gingival fibroblast was not significantly changed by LLL treatment in comparison with control group. But some kinds of protein which might be cell growth promoting factors were decreased immediately after LLL treatment, thereafter were acutely increased in cellular protein profile. 4. In ultrastructural changes of gingival fibroblasts treated by LLL, more prominent rough endoplasmic reticulum, mitochondrial hyperplasia/hypertrophy and increased extracellular fibrillar matrix were observed in comparison with control group under same experimental period.

• Clinical and Experimental Reproductive Medicine
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• 제26권3호
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• pp.483-490
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• 1999

Objectives: Polycystic ovary syndrome (PCOS) has the feature of excessive LH, hyperandrogenism and disturbance of folliculogenesis. Also, insulin, IGF-I and IGFBP-l are involved in the pathogenesis of PCOS. Various surgical and medical therapies have been used and the action mechanisms are related to the endocrine effect. Laparoscopic ovarian electrocautery or laser vaporization is effective in the restoration of ovulation and normal menstrual cycle with minimal invasive procedure especially in the patients resistant to medical therapy. Clomiphen citrate (CC) is used for the ovulation induction in pcas and the resistance is known to be related to insulin, IGF-I, IGFBP-l levels. This study was performed to evaluate the effect of the laparoscopic laser vaporization on the levels of LH, FSH, testosterone, IGF-I and IGFBP-l and on the ovarian response to clomiphen citrate in patients with CC-resistant PCOS. Materials and Methods: The fasting basal serum LH, FSH, testosterone, IGF-I and IGFBP-l level were measured in 10 PCOS patients with CC-resistance and 7 normal controls with regular menstrual cycle. In PCOS, after laparoscopic $CO_2$ laser vaporization, endocrine levels were measured in 1 week interval for 4 weeks and then compared with preoperative levels. Results: In PCOS group, mean serum LH/FSH ratio, testosterone, IGF-I levels were higher and IGFBP-l level was lower than control. LH/FSH ratio decreased from $2.51{\pm}0.67$ to $1.7{\pm}0.6$ (p<0.05) in 2 weeks, to $0.56{\pm}0.2$ (p<0.01) in 3 weeks and to $1.41{\pm}0.3$ (p<0.01) in 4 weeks after operation. Testosterone level decreased from $1.51{\pm}0.82ng/ml$ to $0.65{\pm}0.34ng/ml$ (p<0.05) in 2 weeks, to $0.56{\pm}0.67ng/ml $(p<0.01) in 3 weeks after operation. IGF-I level also decreased from $436{\pm}47.5{\mu}g/l$ to $187{\pm}38{\mu}g/l$ (p<0.0l) in 1 week, to $167{\pm}42{\mu}g/l$ (p<0.01) in 2 weeks, $179{\pm}55{\mu}g/l$ (p<0.01) in 3 weeks and to $120{\pm}43{\mu}g/l$ (p<0.01) in 4 weeks after operation. IGFBP-l level showed no significant change. In 8 of 10 PCOS patients, ovulation was induced with low dose clomiphen citrate. Conclusion: Laparoscopic $CO_2$ laser vaporization restores normal menstrual cycle and ovulation through endocrine effect of decreasing LH/FSH ratio, testosterone and IGF-I level and increases the response to CC. Therefore it is useful for restoration of normal menstruation and induction of ovulation in CC resistant PCOS patients.

• Journal of Oral Medicine and Pain
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• 제23권4호
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• pp.301-307
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• 1998

본 연구에서는 904nm의 다이오드 레이저를 발치창에 조사하여 효과를 분석하교, 동물실험에서 제시된 가설 즉 레이저 광조사가 주위정상조직을 자극하여 창상치유를 촉진하고 진통, 항염증효과가 있는지를 확인하고저 하였다. 먼저 19명의 발치환자에게 발치후 즉시 1분간 평균 14mW의 저수준레이저를 조사하였다. 이들중 8명은 대조군으로서 위조사(sham-irradiation)하였다. 일주일동안 시간경과에 따른 동통의 정도, 진통제의 사용횟수, 진통제 사용기간등을 각각조사하였다. Visual analogue scale로 두근에서 동통의 정도를 비교한 결과 대조군 보다 레이저 조사군에서 동통이 유의하게 감소하였으며, 진통제의 사용횟수가 기간도 레이저조사군에서 유의하게 감소하였다. 이러한 결과로 보아 비록 1분간의 적은 량의 레이저 조사라도 발치후 합병증을 억제하여 동통을 억제하고 치유를 촉진한다고 사료된다.

• Journal of Advanced Marine Engineering and Technology
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• 제37권7호
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• pp.737-742
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• 2013

Recently, unmanned aircrafts for safe measurement in hazardous locations have been developed. In a method of operation of unmanned aircraft vehicles (UAV), there are two methods of manual control and automatic control. Small UAVs are used for low altitude surveillance flights where unknown obstacles can be encountered. Obstacle avoidance is one of the most challenging tasks which the UAV has to perform with high level of accuracy. In this study, we used a laser range finder as an obstacle detector in automatic navigation of unmanned aircraft to patrol the destination automatically. We proposed a system to avoid obstacles automatically by measuring the angle and distance of the obstacle using the laser range finder.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1137-1139
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• 2003

This paper proposed a practical method for building detection and extraction using airborne laser scanning data. The proposed method consists mainly of two processes: low and high level processes. The major distinction from the previous approaches is that we introduce a concept of pseudogrid (or binning) into raw laser scanning data to avoid the loss of information and accuracy due to interpolation as well as to define the adjacency of neighboring laser point data and to speed up the processing time. The approach begins with pseudo-grid generation, noise removal, segmentation, grouping for building detection, linearization and simplification of building boundary , and building extraction in 3D vector format. To achieve the efficient processing, each step changes the domain of input data such as point and pseudo-grid accordingly. The experimental results shows that the proposed method is promising.