• Title/Summary/Keyword: Fixation length

Search Result 155, Processing Time 0.027 seconds

Preliminary clinic study on computer assisted mandibular reconstruction: the positive role of surgical navigation technique

  • Huang, Jin-Wei;Shan, Xiao-Feng;Lu, Xu-Guang;Cai, Zhi-Gang
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.37
    • /
    • pp.20.1-20.7
    • /
    • 2015
  • Background: The objectives of the present study were to investigate the reliability and outcomes of computer-assisted techniques in mandibular reconstruction with a fibula flap and verify whether the surgical navigation system was feasible in mandible reconstructive surgery. Methods: Eight cases were enrolled in the computer assisted surgery (CAS) group and 14 cases in the traditional group. The shaping and fixation of the fibula grafts were guided by computer assisted techniques, which could be monitored with the BrainLAB surgical navigation system. The variation of mandible configuration was evaluated by CT measurement in the Mimics software, including the variation of length, width, height and gonial angle of the mandible. The 3D facial soft tissue alteration was also analyzed in 3D chromatogram by Geomagic software. Results: All 22 fibula flaps survived. The mandibular configurations and facial contours had a better clinic result in the CAS group. The length, width, height and gonial angle of the reconstructive mandible were more similar to the original one. The Wilcoxon rank sum test analysis suggested significant differences in the measurements. The chromatographic analysis also visually showed superiority over the traditional group. Conclusions: The computer assisted surgical navigation method used in mandibular reconstruction is feasible and precise for clinical application. The contour of the reconstructed mandible and facial symmetry are improved with computer techniques.

Breeding of New Productive Bivoltine Hybrid, CSR12 $\times$ CSR6 of Silkworm Bombyx mori L.

  • Datta, R.K.;Basavaraja, H.K.;Reddy, N.Mal;Kumar, S.Nirmal;Kumar, N.Suresh;Babu, M.Ramesh;Ahsan, M.M.;Jayaswal, K.P.
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.3 no.2
    • /
    • pp.127-133
    • /
    • 2001
  • With an objective of evolving quantitatively and qualitatively superior bivoltine breeds/hybrids of silkworm Bombyx mori L. for tropical conditions, breeding work was initiated in Central Sericultural Research and Training Institute, Mysore during 1992 by utilizing two Japanese hybrids namely BNl8$\times$BCS25 and Shunrei$\times$Shogetsu along with Indian evolved breed, KA. The breed CSR12 which is characterized with sex-limited larval marking and white oval cocoons was evolved from the Japanese hybrid BNl8 ${\times}$ BCS25 by crossing with KA, while the breed CSR6 which is characterized with normal marking (marked larvae) and white dumbbell cocoons was extracted from the Japanese commercial hybrid Shunrei${\times}$Shogetsu through continuous inbreeding coupled with selection. After fixation, these breeds along with other newly evolved breeds were subjected to hybrid study under optimum environmental conditions in the laboratory for expression of full potential of the genotypes. These hybrids were evaluated by Multiple Trait Evaluation Index (Mano et al., 1993). The hybrid CSR12${\times}$CSR6 was selected based multiple trait evaluation index value. The hybrid CSR12$\times$CSR6 recorded survival of 96.0%, shell weight of 50.0 cg, shell ratio of 24.3%, raw silk percentage of 19.6, filament length of 1,216 m, boil off loss of 22.4% and renditta of 5.1. On the other hand, the control hybrid (KA ${\times}$ NB4D2) has recorded survival of 90.6%, shell weight of 42.1 cg, shell ratio of 20.4%, raw silk percentage of 15.9, filament length of 999 m, boil off loss of 24.8% and renditta of 6.3. The hybrid CSR12$\times$CSR6 was authorized during 1997 by Central Silk Board, Government of India for commercial exploitation during favourable months based on national level race authorization test.

  • PDF

Effectiveness of ultra-wide implants in the mandibular and maxillary posterior areas: a 5-year retrospective clinical study

  • So-Yeon Kim;Hyeong-Gi Kim;Pil-Young Yun;Young-Kyun Kim
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.49 no.1
    • /
    • pp.13-20
    • /
    • 2023
  • Objectives: Ultra-wide implants may be used as a replacement if existing implants fail. This study was conducted to evaluate the factors influencing the prognosis and failure of ultra-wide implants. Patients and Methods: This study evaluated whether sex, age, site, diameter, length, additional surgery, implant stability (primary and secondary), and reason for ultra-wide implant placement affect the 5-year survival and success rates and marginal bone loss (MBL) of ultra-wide implants. Seventy-eight ultra-wide implants that were placed in 71 patients (39 males and 32 females) from 2008 to 2010 were studied. One-way ANOVA analysis was conducted to evaluate the statistical significance of MBL according to the patient's sex, implant site, and diameter. Independent sample t-tests were used to determine the statistical significance of MBL analysis which was used to determine the significance of the 5-year success and survival rates related to the variables. One-way ANOVA was conducted to evaluate the statistical significance of sex, implantation site, diameter, and MBL. Independent sample t-tests were used to evaluate the correlation between implantability and MBL for implantation reasons, while additional surgery, length, and Kaplan-Meier analysis were used to evaluate 5-year survival and success rates. Results: The mean age of patients was 54.2 years with a survival rate of 92.3% and a success rate of 83.3% over a mean 97.8-month period of observation. MBL averaged 0.2 mm after one year of prosthetic function loading and 0.54 mm at the time of final observation. Success rates correlated with primary stability (P=0.045), survival rates correlated with secondary stability (P=0.036), and MBL did not correlate with any variables. Conclusion: Ultra-wide implants can be used to achieve secure initial fixation in the maxillary and mandibular molar regions with poor bone quality or for alternative purposes in cases of previous implant failure.

Stress Variation Characteristics of Temporary Fixed Steel Rod in FCM Bridge Construction Method (FCM 교량 가설 공법에서 임시 고정 강봉의 응력 변화 특성 )

  • Hyun-Euk Kang;Wan-Shin Park;Young-Il Jang;Sun-Woo Kim;Hyun-Do Yun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.27 no.3
    • /
    • pp.21-29
    • /
    • 2023
  • In this study, the stress characteristics of temporary fixed steel rods were analyzed in the "temporary fixing system using internal prestressing tension", which is mainly applied to the construction of superstructures by FCM. It was difficult to confirm the changes in initial tensile force in this system because the steel rod was internally connected to the pier and the PSC BOX. Therefore, measurement was performed before and after the completion of each segment using an FBG sensor to measure the change in the micro length of the steel rod. The results of the analysis showed that 75% to 90% of the maximum vertical contraction of the steel rod that occurred until the completion of the cantilever segment occurred in the fixing ~ 1segment, and the maximum loss of initial prestressing force was 39%. Such excessive loss of tension force to 1 segment means that tension is needed to improve the precision of construction during the fixation, and re-tension is needed to secure stability for conduction of cantilever segments after the completion of 1segment. In the 2 ~ last segment, the stress of the steel rod decreased gradually, and in the summer, the decrease in stress tended to partially recover due to the increase in the length of the steel rod corresponding to the increase in the vertical volume of PSC BOX. The dominant factor in the stress change in 2~ last segment in this phenomenon is judged to be the change in the length of the steel rod according to the temperature. Unlike the change in length, the relaxation was 1.2-2.7%, which was mostly offset by the opposite stress corresponding to the temperature stress. Therefore, a plan was proposed to improve the internal stress, such as adjusting the fixation time.

Design of the Interspinous Process Fixator Using Biomechanical Analysis for the Treament of Degenerative Lumbar Spinal Stenosis (퇴행성 요추부 척추관 협착증 치료를 위한 극돌기간 고정기구의 설계 및 생체역학적 분석)

  • Heo S.;Son K.;Lee S.J.;Moon B.Y.
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2005.06a
    • /
    • pp.1963-1966
    • /
    • 2005
  • Degenerative lumbar spinal stenosis(DLSS) is a disease inducing low back pain, leg pain, convulsion, numbness, and neurogenic claudication from compression of nerve root. Intervertebra fixation was reported to increase the degenerative of neighbor region after treatment. Recently, a new surgical technique of inserting a fixator between interspinous processes has been introduced. The purpose of this study is to design of the interspinous process fixator with flexibility to complement the trouble of using fixator in DLSS. This study evaluated the existing fixator through the mechanical test and modified fixators using the finite element analysis(FEA). Displacement, stiffness and Von-Mises stress were found to have similar values to those obtained from the mechanical test and the FEA in the biomechanical loading condition. Effects of variation in length and thickness were investigated to design an optimal fixator.

  • PDF

Biomechanical Analysis of Lumbar Interspinous Process Fixators (요추부 극돌기간 고정기구의 생체역학적 해석)

  • Heo Soon;Park Jung-Hong;Lee Sung-Jae;Son Kwon
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.23 no.3 s.180
    • /
    • pp.195-202
    • /
    • 2006
  • The degenerative lumbar spinal stenosis (DLSS) is a disease inducing low back pain, leg pain, convulsion. numbness, and neurogenic claudication from compression of nerve root. Intervertebra fixation was reported to increase the degeneration of neighbor lesion after treatment. Recently, a new surgical technique of inserting a fixator between interspinous processes has been introduced. The purpose of this study is to design the interspinous process fixator with flexibility to complement the trouble of using fixator in DLSS. This study evaluated the existing fixator through the mechanical test and modified it using the finite element analysis (FEA). The evaluation was based on the displacement, stiffness and von-Mises stress obtained from the mechanical test and calculated from the FEA in the biomechanical loading condition. Effects of variation in length and thickness were investigated to design an optimal fixator. Three prototypes were manufactured using FEA results. Mechanical tests under the biomechanical loading condition were performed to select the best one from these three. The selected fixator increased flexiblity by 32.9%.

Optimising the Extraction of Bacteria, Heterotrophic Protists and Diatoms, and Estimating Their Abundance and Biomass from Intertidal Sandy Sediments

  • Lee, Won-Je;Patterson, David J.
    • Journal of the korean society of oceanography
    • /
    • v.37 no.2
    • /
    • pp.58-65
    • /
    • 2002
  • The study of microbial communities in sediments is impaired by the lack of reliable extraction methods. This study reports on the efficiency of recovery of a method for extracting bacteria, protists and diatoms from sandy sediments using a modified decant/fix method. The best extractions were achieved after fixation with a microtubule stabilising fixative and subsequent sonication for 80 seconds. We estimate that the efficiencies of recovery of bacteria and mixed heterotrophic flagellates were $96.4{\pm}3.5\%$ and $96.9{\pm}4.6\%$, respectively. Diatoms were recovered with an efficiency of 38-83% and varied considerably from species to species. This study suggests that the decant/fix method is effective in extracting small cells such as bacteria and heterotrophic flagellates, and that the efficiency of recovery of the method varies due to cell length and different types of organisms. When microbial carbon biomass had been underestimated by up to 32%, with much of that relating to larger cells such as microalgae and ciliates. We note that the corrected abundances may be still a subset of the total numbers present.

Comparative Anatomy of the Korean Native Goat 2. Mesenteric mast cell (한국 재래 산양의 비교해부학적 연구 2. 장간막 비만세포에 대하여)

  • Lee, Heung Shik;Kim, Chang Ki
    • Korean Journal of Veterinary Research
    • /
    • v.14 no.2
    • /
    • pp.151-157
    • /
    • 1974
  • This study was carried out to investigate on the morphology, distribution and stainability of the mast cells in the Korean Native goat. For the study, the experimental animals were anesthetized with pentobarbital sodium and opened the anterior abdomianl wall to remove immediately the specimens with a minimum of mechanical effects. The mesenteries were fixed in 10% neutral formalin, 4% basic lead acetate, absolute alcohol and ethlene glycol monoethyl ether. Following 24 hours of fixation, the toto preparation stained with 0.4% toluidine blue, 1% methylene blue, 1.5% bismark brown, saturated thionine and thionlne-methylene blue complex solution. The preparation were observed from 10 microscopic field with 450 magnification. The results were as follows: 1. The form of the mesenteric mast cell was found 2 types. One was spindle form in larger number around vessels, the other was ovoid or spherical form in connective tissue far from blood vessels. 2. The average size was $18.63{\pm}5.75{\mu}m$ in length, $10.61{\pm}3.39{\mu}m$ in width and number was $105.50{\pm}18.45$. 3. Ethylene glycol monoethyl ether was particularly useful in preserving the mast cell granules. 4. Thione-methylene blue complex solution might be recommended to stain of granules.

  • PDF

Implant-supported overdenture with prefabricated bar attachment system in mandibular edentulous patient

  • Ha, Seung-Ryong;Kim, Sung-Hun;Song, Seung-Il;Hong, Seong-Tae;Kim, Gy-Young
    • The Journal of Advanced Prosthodontics
    • /
    • v.4 no.4
    • /
    • pp.254-258
    • /
    • 2012
  • Implant-supported overdenture is a reliable treatment option for the patients with edentulous mandible when they have difficulty in using complete dentures. Several options have been used for implant-supported overdenture attachments. Among these, bar attachment system has greater retention and better maintainability than others. SFI-Bar$^{(R)}$ is prefabricated and can be adjustable at chairside. Therefore, laboratory procedures such as soldering and welding are unnecessary, which leads to fewer errors and lower costs. A 67-year-old female patient presented, complaining of mobility of lower anterior teeth with old denture. She had been wearing complete denture in the maxilla and removable partial denture in the mandible with severe bone loss. After extracting the teeth, two implants were placed in front of mental foramen, and SFI-Bar$^{(R)}$ was connected. A tube bar was seated to two adapters through large ball joints and fixation screws, connecting each implant. The length of the tube bar was adjusted according to inter-implant distance. Then, a female part was attached to the bar beneath the new denture. This clinical report describes two-implant-supported overdenture using the SFI-Bar$^{(R)}$ system in a mandibular edentulous patient.

Application Strategies of Eye-tracking Method in Nightscape Evaluation (야간경관 평가에서의 아이트래킹 분석 적용 연구)

  • Kang, Youngeun;Kim, Mintai
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.43 no.4
    • /
    • pp.87-97
    • /
    • 2015
  • There's a trend towards vitalization of nightscape planning businesses nationally and locally as well for city image making and activation of regional economy, but there is still no systematic nightscape planning going on for lack of relevant researches and objective evaluations. This study aims to suggest the guideline for nightscape planning by conducting an eye tracking experiment and survey for recognizing the characteristics of a nightscape. Furthermore, the authors intended to verify the eye-tracking method as a tool for landscape evaluation. The research site was restricted in the campus of Virginia Tech, VA, and those were selected by experts' survey among various types of nightscape images. The variables for analyzing the characteristics of nightscape images selected were 'preference', 'safety(fear)' and 'clearness'. 'Fixation duration', 'saccade duration', 'scan path length', and 'pupil size' were selected as the eye movement measurements. The results of this study are as follows: The first outcome found was that there were significant differences among the characteristics(preference, safety and clearness) of a nightscape by MANOVA, and these variables were correlated positively by Pearson's correlation. Secondly, there were differences on fixation duration, saccade duration and scan path depending on the nightscape setting statistically. Also, the eye tracking measurement in an open setting was recorded lower than enclosed settings. In the result of a heat map, we found the meaning of the fixated areas on both viewing without intention and viewing intentionally. It turned out that the fixated areas were consistent with the areas the subjects felt preferred and clarity in all of the nightscape images, which means people usually focus on what they prefer and see clearly in a certain nightscape. Based on this result and previous studies, the authors could make a conclusion that eye tracking method can apply to evaluate nightscape settings in terms of analyzing the whole characteristics and finding specific points for the detailed analysis as well. Therefore, these results can contribute by suggesting nightscape planning, implication of the landscape evaluation, and implication of the eye tracking study.