• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.1
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• pp.20-26
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• 2019

Purpose: Recently TF-adaptive movement is developed in order to increase the durability of TF files. The purpose of this study was to assess the effects of adaptive movement on durability and performance of twisted files. Materials and Methods: Resin blocks simulating artificial J-shape canals were used for this study. In TFC group, TF-adaptive ML-1 (25/.08 size) files were used to prepare the canals under continuous rotation 500 rpm/4.0 Ncm. In TFA group, TF-adaptive ML-1 (25/.08 size) files were used to prepare the canals under adaptive movement. After preparing each artificial canal, TF files were observed under dental microscope for assessing existence of unwinding, distortion, and fracture. If unwinding of flute was observed, the number of artificial canals until unwinding of flute occurs was recorded. Required time until instruments reach working length and distance of unwinded portion of files from D0 were measured. All test results were conducted by Mann-Whitney U test at a 0.05 level of significance. Results: No Ni-Ti instrument's separation was observed. Number of resin blocks until file unwinding happens and working time was significantly high in TFA group compared to TF group. Distance of distortion from D0 didn't show significant difference between TFA, TF groups. Conclusion: The number of resin blocks prepared until unwinding happens and working time were significantly high in TFA group. The location of unwinding showed no significant difference between 2 groups. Adaptive movement increased the number of canals prepared until unwinding occurs and working time of twisted files.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.729-742
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• 2020

In this study, we analyze seabottom conditions and characteristics integrated with topographic data, seafloor mosaic, underwater images and orthophoto(drone) of soft-hard bottom area around the Sib-Ri rock in the northern shore of the East Sea(Gyeongpo Beach, Gangneung). We obtained field survey data around the Sib-Ri rock(about 600 m × 600 m). The Sib-Ri rock is formed by two exposed rocks and surrounding reef. The artificial reef zone made by about 200 ~ 300 structures is shown the western area of the Sib-Ri rock. The underwater rock region is extended from the southwestern area of the exposed the Sib-Ri rock with 9 ~ 11 m depth range. The most broad rocky seabottom area is located in the southwestren area of the Sib-Ri rock with 10 ~ 13 m depth range. The study area were classified into 4 types of seabottom environment based on the analysis of bathymetric data, seafloor mosaics, composition of sediments and images(underwater and drone). The underwater rock zones(Type I) are the most distributed area around the Sib-Ri Rock(about 600 m × 600 m). The soft seabottom area made by sediments layer showed 2 types(Type II: gS(gravelly Sand), Type III: S(Sand)) in the areas between underwater rock zones and western part of the Sib-Ri rock(toward Gyeongpo Beach). The artificial reef zone with a lot of structures is located in the western part of the Sib-Ri rock. Marine algae(about 6 species), Phylum porifera(about 2 species), Phylum echinodermata(about 3 species), Phylum mollusca(about 3 species) and Phylum chordata(about 2 species) are dominant faunal group of underwater image analysis area(about 10 m × 10 m) in the northwestern part of the Sib-Ri rock. The habitat of Phylym mollusca(Lottia dorsuosa, Septifer virgatus) and Phylum arthropoda(Pollicipes mitella, Chthamalus challengeri hoek) appears in the intertidal zone of the Sib-Ri rock. And it is possible to estimate the range and distribution of the habitat based on the integrated study of orthphoto(drone) and bathymetry data. The integrated visualization and mapping techniques using seafloor mosaic images, sediments analysis, underwater images, orthophoto(drone) and topographic data can provide and contribute to figure out the seabottom conditions and characteristics in the shore of the East Sea.

• Journal of the Korean Orthopaedic Association
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• v.55 no.2
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• pp.135-142
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• 2020

Purpose: This paper presents the long term follow-up results of arthroscopic partial repair for massive irreparable rotator cuff tears using a biceps long head auto graft. Materials and Methods: Forty-one patients with massive irreparable rotator cuff tear, who underwent arthroscopic repair, were reviewed retrospectively. Patients who underwent arthroscopic partial repair using a biceps long head auto graft were assigned to group 1, and patients in group 2 underwent arthroscopic partial repair alone. Patients with a less than 50% partial tear of the long head biceps tendon were included in this study. The clinical scores were measured using a visual analogue pain scale (VAS) for pain, range of motion (ROM), The University of California, Los Angeles shoulder score (UCLA), American Shoulder and Elbow Surgeons Shoulder Score (ASES), and Korean Shoulder Scoring System (KSS) scores preoperatively and at the final follow-up. The acromiohumeral interval (AHI) was measured using plain radiographs taken preoperatively and at the final follow-up, and re-tear was evaluated using postoperative ultrasound or magnetic resonance imaging at the last follow-up. Results: The mean age of the patients was 62.1±12.7 years, and the mean follow-up period was 90.3±16.8 months. No significant differences in the VAS and ROM (forward flexion, external rotation, internal rotation) were found between the two groups (p=0.179, p=0.129, p=0.098, p=0.155, respectively). The UCLA (p=0.041), ASES (p=0.023), and KSS (p=0.019) scores showed functional improvements in group 1 compared to group 2. At the last follow-up, the measured AHI values were 9.46±0.41 mm and 6.86±0.64 mm in group 1 and 2, respectively (p=0.032). Re-tear was observed in six out of 21 cases (28.6%) in group 1 and nine out of 20 cases (45.0%) in group 2; the retear rate was significantly lower in group 1 than in group 2 (p=0.011). Conclusion: Arthroscopic partial repair for a massive irreparable rotator cuff tear using a biceps long head auto graft has significant clinical usefulness in functional recovery and decreases the re-tear rates after surgery than arthroscopic partial repair alone, showing favorable results after a long-term follow-up.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.1
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• pp.1-8
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• 2005

Purpose : An effect of a packing to uterine treatment of a cervical cancer using a dose-volume histogram for a point dose and a volume dose of the bladder and the rectum was analyzed by establishing a three-dimensional treatment plan using a CT image. Materials and methods : Reference points of the bladder and the rectum were marked, respectively at a treatment plan device (plato brachytherapy V14.2.4) by photographing CT(marconi, USA) when the packing was used and removed under the same condition and a treatment plan was performed to Apoint depending on ICRU38. However, in case of the rectum, a maximum point was looked up and compared with the above point because the point presented from the ICRU is not proper as a representative value of a rectum point dose. Further, the volume dose depending on volume of $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder was measured. The measured values were used to analyze the effect of the packing through a Wilcoxon Signed Rank Test (a SAS statistical analysis process program). Result : The reference points at the bladder and rectum doses when the packing was removed were $116.94\;35.42\%$ and $117.59\;21.08\%$, respectively. The points when the packing was used were $107.08\;38.12\%$ and $95.19\;21.32\%$, respectively. After the packing was used, the reference points at the bladder and the rectum were decreased by $9.86\%$ and $22.4\%$, respectively. When the packing was removed, the maximum points at the bladder and the rectum were $164.51\;50.89\%,\;128.81\;33.05\%$, respectively. When the packing was used, the maximum points at the bladder and the rectum were $142.31\;44.79,\;110.08\;37.03\%$, respectively. After the packing was used, the maximum points at the bladder and the rectum were decreased by $22.2\%$ and $18.73\%$, respectively. When the packing was removed, the bladder volume at $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder were $48.62{\pm}18.09\%,\;16.12{\pm}11.15\%,\;and\;7.51{\pm}6.63\%$, respectively and its rectum volume were $23.41{\pm}14.44\%,\;6.27{\pm}4.28\%,\;2.79{\pm}2.27\%$, respectively. When the packing was used, the bladder volume at $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder were $40.33{\pm}16.72,\;11.63{\pm}8.72,\;and\;4.87{\pm}4.75\%$, respectively and its rectum volume were $18.96{\pm}8.37\%,\;4.75{\pm}2.58\%,\;and\;1.58{\pm}1.06\%$, respectively. After the packing was used, the bladder volume at $50\%,\;80\%,\;and\;100\%$ point doses of the rectum and the bladder were decreased by $8.29\%,\;4.49\%,\;and\;2.64\%$, respectively and its bladder volume were decreased by $4.45\%,\;1.52\%,\;and\;1.21\%$, respectively. Conclusion : Values at Reference point doses of the bladder and the rectum recommended from the ICRU 38 were 0.0781 and 0.0781, respectively and values of their maximum point doses were 0.0156 and 0.0156, respectively, as a result of which an effect of the packing using at the uterine intracavitary treatment of an uterine cervical cancer through the three-dimensional treatment plan used CT were measured. That is, the values at reference point doses and the values at maximum point doses show similar difference. However, P value was 0.15 at over $50\%,\;80\%,\;and\;100\%$ volume doses and the value shows no similar difference. In other words, the effect of the packing looks like having a difference at the point dose, but actually shows no difference at the volume dose. The reason is that the volume of the bladder and the rectum are wide but the volume of the packing is only a portion. Therefore, the effect of decreasing the point dose was not great. Further, the farer the distance is, the more weak the intensity of radiation is because the intensity of radiation is proportional to inverse square of a distance. Therefore, the effort to minimize an obstacle of the bladder and the rectum by using the packing should be made.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.94-100
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• 2010

Purpose: We can evaluate function of kidney by Glomerular Filtration Rate (GFR) test using $^{99m}Tc$-DTPA which is simple. This test is influenced by several parameter such as net syringe count, kidney depth, corrected kidney count, acquisition time and characters of gamma camera. In this study, we evaluated predose count according to matrix size in the GFR test using $^{99m}Tc$-DTPA. Materials and Methods: Gamma camera of Infinia in GE was used, and LEGP collimator, three types of matrix size ($64{\times}64$, $128{\times}128$, $256{\times}256$) and 1.0 of zoom factor were applied. We increased radioactivity concentration from 222 (6), 296 (8), 370 (10), 444 (12) up to 518 MBq (14 mCi) respectively and acquired images according to matrix size at 30 cm distance from detector. Lastly, we evaluated these values and then substituted them for GFR formula. Results: In $64{\times}64$, $128{\times}128$ and $256{\times}256$ of matrix size, counts per second was 26.8, 34.5, 41.5, 49.1 and 55.3 kcps, 25.3, 33.4, 41.0, 48.4 and 54.3 kcps and 25.5, 33.7, 40.8, 48.1 and 54.7 kcps respectively. Total counts for 5 second were 134, 172, 208, 245 and 276 kcounts from $64{\times}64$, 127, 172, 205, 242, 271 kcounts from $128{\times}128$, and 137, 168, 204, 240 and 273 kcounts from $256{\times}256$, and total counts for 60 seconds were 1,503, 1,866, 2,093, 2,280, 2,321 kcounts, 1,511, 1,994, 2,453, 2,890 and 3,244 kcounts, and 1,524, 2,011, 2,439, 2,869 and 3,268 kcounts respectively. It is different from 0 to 30.02 % of percentage difference in $64{\times}64$ of matrix size. But in $128{\times}128$ and $256{\times}256$, it is showed 0.60 and 0.69 % of maximum value each. GFR of percentage difference in $64{\times}64$ represented 6.77% of 222 MBq (6 mCi), 42.89 % of 518 MBq (14 mCi) at 60 seconds respectively. However it is represented 0.60 and 0.63 % each in $128{\times}128$ and $256{\times}256$. Conclusion: There was no big difference in total counts of percentage difference and GFR values acquiring from $128{\times}128$ and $256{\times}256$ of matrix size. But in $64{\times}64$ of matrix size when the total count exceeded 1,500 kcounts, the overflow phenomenon was appeared differently according to predose radioactivity of concentration and acquisition time. Therefore, we must optimize matrix size and net syringe count considering the total count of predose to get accurate GFR results.