• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.413-419
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• 2007

The aims of this study were to investigate the relationships among several types of thermal pain thresholds, and pressure pain thresholds. This study was designed to examine whether there were associations among different types of pain thresholds, and among different recording sites for each pain threshold measurement. Pain sensitivity thresholds including cold pain threshold (CPT), heat pain threshold (HPT), heat pain tolerance threshold (PTT), and pressure pain threshold (PPT) of 56 subjects with symptoms of temporomandibular disorders were measured on temporal muscle, masseter muscle, TMJ, and tibial areas. Thermal pain thresholds including CPT, HPT, and PTT did not show any gender differences. However, women showed significantly lower PPTs than men on all recording sites. Three thermal pain thresholds including CPT, HPT, and PTT showed weak to high correlations on all the recording sites (r= 0.324 to 0.754, p<0.05). PPTs did not show any significant correlations between each thermal pain threshold. The pain threshold of each recording site showed weak to high correlations in all pain threshold measures (r= 0.284 to 0.878, p<0.05). Our study demonstrated that thermal pain thresholds, and pain tolerance thresholds were significantly correlated, but did not show any correlation between thermal pain thresholds and pressure pain thresholds. There were relatively high correlations among the pain thresholds of different recording sites.

• Journal of Oral Medicine and Pain
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• v.37 no.4
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• pp.243-250
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• 2012

Trigeminal nerve injuries due to invasive dental procedures such as implant surgery and extraction is one of the most serious issues in dentistry and may provoke medico-legal problems. Thus, for objective and reliable assessment of nerve injury, a need of QST (quantitative sensory testing) is emphasized and thermal threshold test is an essential part of QST, reported to have acceptable reliability in the orofacial region. This pilot study aimed to evaluate thermal thresholds for limited cases of trigeminal nerve injures. The study investigated 18 clinical cases with trigeminal nerve injuries who visited Department of Oral Medicine, Dankook Univeristy Dental Hospital during the period from May 2011 to Oct 2012. Thermal thresholds was measured by Thermal Sensory Analyzer, TSA-II (Medoc, Israel). Their CDT(cold detection threshold) was significantly decreased in the affected sides compared to the unaffected sides. Other parameters such as WDT(warm detection threshold), CPT(cold pain threshold) and HPT(heat pain threshold) did not show statistical difference between the affected and unaffected sides. Further researches are required to compare thermal thresholds relative to types of nerve deficits such as thermal hyper- or hypoesthesia and hyper- or hypoalgesia for larger sample.

• Journal of Oral Medicine and Pain
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• v.38 no.4
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• pp.367-372
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• 2013

To diagnose sensory nerve damage, patient values for thermal stimuli as quantitative sensory test (QST) can be compared with the values of the general population (absolute reference data) or to values measured at contralateral unaffected side (relative reference data). It is well know that relative reference data are more sensitive for detecting sensory abnormality than absolute reference data. However it is still lack of the studies for comparisons between relative and absolute data. This study aimed to evaluate the validity of relative reference data and compare the sensitivities of the two approaches in the orofacial region. In 19 young Korean women as normal subjects, quantitative somatosensory thermotest were done in the forehead, cheek, mentum, lower lip and tongue tip bilaterally. After we get the standard deviations (SD) of average reference data and relative reference data, the ratios SD absolute data/SD relative data were calculated. Our study showed that relative reference data for side to side comparisons in the same patient have the high ratios than the absolute reference data, i.e. the side to side comparisons with relative reference data exhibit gain in sensitivity in assessment of sensory abnormality.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.11
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• pp.897-903
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• 2015

In this paper, the contrast therapy of skin was numerically investigated by solving the conjugate heat transfer problem. A finite volume method based on the SIMPLE algorithm was adopted to solve the axisymmetric incompressible Navier-Stokes equations, coupled with an energy equation. These equations are strongly coupled with the Pennes bio-heat equation in order to consider the effect of blood perfusion rate. We investigated the thermal response of skin at some selected depths for various input temperature profiles of a stimulator for contrast therapy. From the numerical simulations, the regions with cold/hot threshold temperatures were found for five input temperature profiles. It was shown that the temperature varies mildly for different input profiles as the depth increases, owing to the Pennes effect. The input temperatures for effective hot/cold stimulation of dermis layer were found to be $47^{\circ}C$ and $7^{\circ}C$, respectively. The present numerical results will be used for finding an optimal temperature profile of a stimulator for contrast therapy.

• Journal of Food Hygiene and Safety
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• v.14 no.4
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• pp.319-326
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• 1999

Recently, it is continuously rising to concern about the health risk being induced by microorganisms in food such as Escherichia coli O157:H7 and Listeria monocytogenes. Various organizations and regulatory agencies including U.S.FPA, U.S.DA and FAO/WHO are preparing the methodology building to apply microbial quantitative risk assessment to risk-based food safety program. Microbial risks are primarily the result of single exposure and its health impacts are immediate and serious. Therefore, the methodology of risk assessment differs from that of chemical risk assessment. Microbial quantitative risk assessment consists of tow steps; hazard identification, exposure assessment, dose-response assessment and risk characterization. Hazard identification is accomplished by observing and defining the types of adverse health effects in humans associated with exposure to foodborne agents. Epidemiological evidence which links the various disease with the particular exposure route is an important component of this identification. Exposure assessment includes the quantification of microbial exposure regarding the dynamics of microbial growth in food processing, transport, packaging and specific time-temperature conditions at various points from animal production to consumption. Dose-response assessment is the process characterizing dose-response correlation between microbial exposure and disease incidence. Unlike chemical carcinogens, the dose-response assessment for microbial pathogens has not focused on animal models for extrapolation to humans. Risk characterization links the exposure assessment and dose-response assessment and involve uncertainty analysis. The methodology of microbial dose-response assessment is classified as nonthreshold and thresh-old approach. The nonthreshold model have assumption that one organism is capable of producing an infection if it arrives at an appropriate site and organism have independence. Recently, the Exponential, Beta-poission, Gompertz, and Gamma-weibull models are using as nonthreshold model. The Log-normal and Log-logistic models are using as threshold model. The threshold has the assumption that a toxicant is produce by interaction of organisms. In this study, it was reviewed detailed process including risk value using model parameter and microbial exposure dose. Also this study suggested model application methodology in field of exposure assessment using assumed food microbial data(NaCl, water activity, temperature, pH, etc.) and the commercially used Food MicroModel. We recognized that human volunteer data to the healthy man are preferred rather than epidemiological data fur obtaining exact dose-response data. But, the foreign agencies are studying the characterization of correlation between human and animal. For the comparison of differences to the population sensitivity: it must be executed domestic study such as the establishment of dose-response data to the Korean volunteer by each microbial and microbial exposure assessment in food.

• Journal of Korean Physical Therapy Science
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• v.3 no.3
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• pp.25-34
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• 1996

The purpose of this experimental study was conducted to examine the most effective modality between two methods of cold application(ice pack and cold spray), the most effective length of time for the application and the continuing effect after each type of cold application. Sixty students were assigned randomly to each of two cold application methods; (a) ice pack, (2) cold spray. Each methods was applied to the posterior surface of right forearm with subject in the sitting position. Skin temperature and the electrical stimulation induced pain threshold were measured before each application and every five degree ($^{\circ}C$) decline point after ice pack application. They were also measured point of minimum skin temperature after cold spray application. The results of this study are as follows; 1. Skin temperatures according to the cold spray application decreased to a range of $4.2^{\circ}C{\sim}9.2^{\circ}C$(male, p<0.001), $3.6^{\circ}C{\sim}7.6^{\circ}C$(female, p<0.001). 2. Pain threshold according to the cold spray application increased to a range of $0.6mA{\sim}1.9mA$(male, p<0.01), $1.2mA{\sim}3.86mA$(female, p>0.05).

• Journal of Korean Neurosurgical Society
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• v.30 no.3
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• pp.272-277
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• 2001

Objective : Polymethylmethacrylate(PMMA) is often used to reconstruct the spine after total corpectomy, but the exothermic curing of liquid PMMA poses a risk of thermal injury to the spinal cord. The purposes of this study are to analyze the heat blocking effect of pre-polymerized PMMA sheet in the corpectomy model and to establish the minimal thickness of PMMA sheet to protect the spinal cord from the thermal injury during PMMA cementation of vertebral body. Materials & Methods : An experimental fixture was fabricated with dimensions similar to those of a T12 corpectomy defect. Sixty milliliters of liquid PMMA were poured into the fixture, and temperature recordings were obtained at the center of the curing PMMA mass and on the undersurface(representing the spinal cord surface) of a prepolymerized PMMA sheet of variable thickness(group 1 : 0mm, group 2 : 5mm, or group 3 : 8mm). Six replicates were tested for each barrier thickness group. Results : Consistent temperatures($106.8{\pm}3.9^{\circ}C$) at center of the curing PMMA mass in eighteen experiments confirmed the reproducibility of the experimental fixture. Peak temperatures on the spinal cord surface were $47.3^{\circ}C$ in group 2, and $43.3^{\circ}C$ in group 3, compared with $60.0^{\circ}C$ in group 1(p<0.00005). So pre-polymerized PMMA provided statistically significant protection from heat transfer. The difference of peak temperature between theoretical and experimental value was less than 1%, while the predicted time was within 35% of experimental values. The data from the theoretical model indicate that a 10mm barrier of PMMA should protect the spinal cord from temperatures greater than $39^{\circ}C$(the threshold for thermal injury in the spinal cord). Conclusion : These results suggest that pre-polymerized PMMA sheet of 10mm thickness may protect the spinal cord from the thermal injury during PMMA reconstruction of vertebral body.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.168-176
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• 2011

Purpose: This study aims at investigating the influence of various insertion torques on thermal changes of bone. A proper insertion torque is derived based on the thermal analysis with two different implant designs. Materials and methods: For implant materials, bovine scapula bone of 15 - 20 mm thickness was cut into 35 mm by 40 - 50 mm pieces. Of these, the pieces having 2 - 3 mm thickness cortical bone were used as samples. Then, the half of the sample was immersed in a bath of $36.5^{\circ}C$ and the other half was exposed to ambient temperature of $25^{\circ}C$, so that the inner and surface temperatures reached $36.5^{\circ}C$ and $28^{\circ}C$, respectively. Two types of implants ($4.5{\times}10\;mm$ Br${\aa}$nemark type, $4.8{\times}10\;mm$ Microthread type) were inserted into bovine scapula bone and the temperature was measured by a thermocouple at 0.2 mm from the measuring point. Finite element method (FEM) was used to analyze the thermal changes at contacting surface assuming that the sample is a cube of $4\;cm{\times}4\;cm{\times}2\;cm$ and a layer up to 2 mm from the top is cortical bone and below is a cancellous bone. Boundary conditions were set on the basis of the shape of cavity after implants. SolidWorks was used as a CAD program with the help of Abaqus 6.9-1. Results: In the in-vitro experiment, the Microhead type implant gives a higher maximum temperature than that of the Br${\aa}$nemark type, which is attributed to high frictional heat that is associated with the implant shape. In both types, an Eriksson threshold was observed at torques of 50 Ncm (Br${\aa}$nemark) and 35 Ncm (Microthread type), respectively. Based on these findings, the Microthread type implant is more affected by insertion torques. Conclusion: This study demonstrate that a proper choice of insertion torque is important when using a specific type of implant. In particular, for the Microthread type implant, possible bone damage may be expected as a result of frictional heat, which compensates for initial high success rate of fixation. Therefore, the insertion torque should be adjusted for each implant design. Furthermore, the operation skills should be carefully chosen for each implant type and insertion torque.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.1
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• pp.23-33
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• 2007

It has been reported high concentrations of zinc and taurine in ocular tissue, especially the retina-choroid, and the presence of physiological levels of zinc and taurine in these tissues seem essential for their normal function. In addition, several studies have reported temperature as another effector to the visual sensitivity. But, in spite of many studies, there are still remained many questions about their function and correlation in visual adaptation system. The purpose of present study was to clarify these points using electroretinogram(ERG) recording and absorption spectra scanning, before and after zinc and taurine treatments and hypothermic-effect in bullfrog(Rana catesbeiana) which is one of the poikilothermal animal. The optimal zinc concentration used in this study was determined $10^{-4}M$ while the optimal taurine concentration was 10-5 M, and temperature change for hypothermic-effect went through '$25^{\circ}C {\rightarrow}0^{\circ}C{\rightarrow}25^{\circ}C$'. In ERG recording, it is obtained that dark-adapted threshold became elevated and b-wave amplitudes was increased with zinc and taurine treatment and hypothermic-effect. In absorption spectra scanning, there is distinct absorbance increment over the whole spectral range(400~750 nm) after zinc and taurine treatment and hypothermic-effect. Furthermore there are some synergism effects between zinc and taurine as well as between zinc and hypothermic-effect as a result of co-treatment, respectively.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.357-364
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• 1988

By implementing epoch-making policies for industrial promotion, the national economy has made a remarkable development. As a result of such economic growth, industrial accidents and occupational diseases have become a serious problem in Korean society. In the presidential order for the execution of the Korean Labor Standard Law, neuritis and other diseases stemming from health impairments due to vibrations in industrial processes are designated to be dealt with as vibration diseases. In the case of vibration disease, industrial accident compensation is not effectively paid. In order to investigate the vibration hazards of rock-drill operation, the authors studied the subjective symptoms and performed physical function tests on a total of 79 persons (vibration exposed group) who used rock-drills, and 39 persons (control group) who did not use rock-drills at anthracite mines. The results of the physical function test were as follosws : 1. The right hand was more affected by white finger than the left hand. 2. Independent variables such as duration of rock-drill operation, age, drinking and smoking were indentified as statistically significant factors for the occurrence of white finger. 3. In the pain sense threshold, the group with Raynaud's phenomenon showed a statistically higher level than that of the control group. 4. The skin temperature of the group with Raynaud's phenomenon was lower than that of the control group. The recovery time of skin temperature aftr cooling was delayed compared with the value of the control group.