• Tuberculosis and Respiratory Diseases
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• v.49 no.6
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• pp.715-723
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• 2000

Background : Obstructive sleep apnea syndrome (OSAS) affects systemic blood pressure and cardiac function. The development of cardiovascular dysfunction including the changes of systemic blood pressure and cardiac rhythm, suggests that recurrent hypoxia and arousals from sleep may increase a sympathetic nervous system activity. Continuous positive airway pressure (CPAP) therapy has been found to be an effective treatment of OSAS. However, only a few studies have investigated the cardiovascular and sympathetic effects of CPAP therapy. We evaluated influences of nasal CPAP therapy on the cardiovascular system and the sympathetic activity in patients with OSAS. Methods : Thirteen patients with OSAS underwent CPAP therapy and were monitored using polysomnography, blood pressure, heart rate, presence of arrhythmia and the concentration of plasma catecholamines, before and with CPAP therapy. Results: The apnea-hypopnea index (AHI) was significant1y decreased (p<0.01) and the lowest arterial oxygen saturation level was elevated significantly after applying CPAP (p<0.01). Systolic blood pressure tended to decrease after CPAP but without statistical significance. Heart rates during sleep were not significantly different after CPAP. However, the frequency and number of types of arrhythmia decreased and sinus bradytachyarrhythmia disappeared after CPAP. Although there was no significant difference in the level of plasma epinephrine concentration, plasma norepinephrine concentration significantly decreased after CPAP (p<0.05). Conclusion : CPAP therapy decreased the apnea-hypopnea index, hypoxic episodes and plasma norepinephrine concentration. In addition, it decreased the incidence of arrhythmia and tended to decrease the systemic blood pressure. These results indicate that CPAP may play an important role in the prevention of cardiovascular complications in patients with OSAS.

• Tuberculosis and Respiratory Diseases
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• v.45 no.5
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• pp.1039-1046
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• 1998

Background: Sleep-related breathing disorders(SRBD) and periodic leg movements disorder(PLMD) are both common, and are considered as separate sleep disorders. However, both disorders show high comorbidity. SRBD and PLMD can result in excessive daytime sleepiness and insomnia due to frequent sleep fragmentation. So, it is very important to consider the presence of PLMD, when we are dealing with the diagnosis and management of SRBD. The objectives of this study were to determine the incidence of PLMD in patients with SRBD, and to describe any differences between patients with and without PLMD. Method: The authors reviewed the sleep recordings of 106 patients with a final diagnosis of SRBD(obstructive sleep apnea or upper airway resistance syndrome), who underwent full nocturnal polysomnography, including the monitoring of the anterior tibialis electromyogram. All sleep records were recorded and scored using the standard criteria. The data was analyzed by the student t-test. Result: 106 patients(M=76, F=30) were included in the analysis. Data revealed a mean age of $49.5{\pm}13.6$ years, a respiratory disturbance index(RDI) of $22.3{\pm}25.4$/hour sleep, a lowest oxygen saturation of $84.9{\pm}11.3%$, a maximal esophageal pressure of $-41.0{\pm}19.1cmH_2O$, and PLM index(PLMI) of $13.1{\pm}22.4$movements/hour sleep. Forty four percent(47 of 106 patients) had a PLMI of greater than 5 on this study. The mean age of the patients with PLMD was significantly higher than that of the patients without PLMD(p<0.005). Female patients with SRBD accompanied more PLMD(p<0.05). The apnea index of the patients with PLMD was significantly lower than that of the patients without PLMD(p<0.01). The percentage of stage 1 sleep in the patients with PLMD was significantly lower than that of the patients without PLMD(p<0.05). Conclusion: The prevalence of PLMD in the patients with SRBD was high at 44.3%. The patients with PLMD were older and had more high RDI in comparison to the patients without PLMD, which was consistent with previous findings. The authors recommend that more careful consideration of PLMD is required when diagnosing and treating SRBD.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.352-358
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• 2005

Microsatellites are short tandem repeated nucleotide sequences that are present throughout the human genome. Variations in the repeat number or a loss of heterozygosity around the microsatellites have been termed a microsatellite alteration (MA). A MA reflects the genetic instability caused by an impairment in the DNA mismatch repair system and is suggested to be a novel tumorigenic mechanism. A number of studies have reported that MA in the DNA extracted from the plasma occurs at varying frequencies among patients with a non-small cell lung carcinoma (NSCLC). The genomic DNA from 9 subjects with a non-small cell lung cancer (squamous cell cancer 6, adenocarcinoma 2, non-small cell lung cancer1) and 9 age matched non-cancer control subjects (AMC: tuberculosis 3, other inflammatory lung disease 6) and 12 normal control subjects (NC) were extracted from the peripheral blood leukocytes and plasma. Three microsatellite loci were amplified with the primers targeting the Gene Bank sequence D21S1245, D3S1300, and D3S1234. MA in the form of an allelic loss or a band shift was examined with 6% polyacrylamide gel electrophoresis and silver staining. None (0/12) of the NC subjects less than 40 years of age showed a MA in any of the three markers, while 88.9%(8/9) of the AMC above 40 showed a MA in at least one of the three markers (p<0.05). Sixty percent(6/10) of the control subjects with a smoking history showed a MA in one of the three markers, while 9.1%(1/11) of the control subjects without smoking history showed a MA (p<0.05). However, not only did 66.7%(6/9) of lung cancer patients show a MA in at least one of the three markers but so did 88.9%(8/21) of the AMC patients (p>0.05). In conclusion, a MA in the D21S1245, D3S1300, and D3S1234 loci using DNA extracted from the plasma was detected in 66.7% of lung cancer while no MA was found in the young non-smoking control subjects. However, many of the non-cancer control subjects (aged smokers) also showed a MA, which compromised the specificity of the MA analysis as a screening test. Therefore, a further study with a larger sample size will be needed.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.375-384
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• 2005

Background and Aims : Pre-induction of heat shock protein 70 (HSP70) is known to effectively attenuate the lipopolysaccharide (LPS)-induced inflammatory response in lung tissue. However, it is unclear if HSP70 induction after LPS exposure attenuates the subsequent LPS-induced inflammatory response in alveolar epithelial cells. This study examined the effects of HSP70 induction after LPS exposure on the IL-6 production and the cell viability after a subsequent LPS challenge in murine alveolar epithelial cells, and investigated whether or not HSP70 itself may be involved in those effects. Methods : Murine alveolar epithelial cells were cultured and divided into two groups; the Non-Pre-LPS group without a LPS pre-treatment and the Pre-LPS group with a LPS pre-treatment. Each group was subdivided into the following four subgroups: subgroup C (control), subgroup Q (quercetin), subgroup HSP70 (HSP70 induction), and subgroup HSP70-Inh (HSP70 inhibition). HSP70 expression, which was induced by sodium arsenite and inhibited by quercetin, was analyzed by western blot analysis. The IL-6 levels in the culture supernatant were measured by ELISA, and the cell viability was measured using a simplified MTT assay. Results : The IL-6 levels were lower in subgroup HSP70 than in subgroup C (P<0.01), and were higher in subgroup HSP70-Inh than in subgroup HSP70 in both the Non-Pre-LPS and Pre-LPS groups (P<0.05, P<0.01). The cell viability tended to decrease in the Pre-LPS group compared with the Non-Pre-LPS group. While the cell viability was higher in subgroups Q, HSP70, and HSP70-Inh than in subgroup C in the Non-Pre-LPS group (P<0.05, P<0.05, P<0.01), there was no difference in cell viability among the subgroups in the Pre-LPS group. Conclusion : HSP70 induction after a LPS pre-treatment in murine alveolar epithelial cells inhibits the subsequent LPS-induced IL-6 production without affecting the cell viability, and HSP70 by itself may play an important role in this proccess.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.661-674
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• 2005

The purpose of this study was to quantify and compare the level of MMP-2, MMP-8 in the healthy, inflammed gingival tissue and inflammed gingival tissue associated with type 2 DM. We investigate whether expression of MMP-2, MMP-8 is increased by chronic periodontitis associated with type 2 DM. Gingival tissue samples were obtained during periodontal surgery or tooth extraction. Based on patient's systemic condition & clinical criteria of gingiva, each gingival samples were divided into three groups. Group l(n=8) is clinically healthy gingiva without bleeding and no evidence of bone resorption or periodontal pockets, obtained from 8 systemically healthy patients. Group 2(n=8) is inflammed gingiva from patients with chronic periodontitis. Group 3(n=8) is inflammed gingiva from type 2 diabetic patients with chronic periodontitis. Tissue samples were prepared and analyzed by Western blotting. The quantification of MMP-2, MMP-8 was performed using a densitometer and statistically analyzed by ANOVA. MMP-2, MMP-8 was expressed in all samples including healthy gingiva and increased in group 3 compared to group 1 and 2, and showed that significant variation was observed between group 1 & 3 in MMP-8 results. In conclusion, this study demonstrated that human gingival tissue with chronic periodontitis associated to type 2 diabetes showed slightly elevated MMP-2, MMP-8 levels compared to healthy gingiva and non-diabetic inflamed gingiva.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.2
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• pp.182-206
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• 2003

Statement of problem : Successful osseointegration of endosseous threaded implants is dependent on many factors. These may include the surface characteristics and gross geometry of implants, the quality and quantity of bone where implants are placed, and the magnitude and direction of stress in functional occlusion. Therefore clinical quantitative measurement of primary stability at placement and functional state of implant may play a role in prediction of possible clinical symptoms and the renovation of implant geometry, types and surface characteristic according to each patients conditions. Ultimately, it may increase success rate of implants. Purpose : Many available non-invasive techniques used for the clinical measurement of implant stability and osseointegration include percussion, radiography, the $Periotest^{(R)}$, Dental Fine $Tester^{(R)}$ and so on. There is, however, relatively little research undertaken to standardize quantitative measurement of stability of implant and osseointegration due to the various clinical applications performed by each individual operator. Therefore, in order to develop non-invasive experimental method to measure stability of implant quantitatively, the resonance frequency analyzer to measure the natural frequency of specific substance was developed in the procedure of this study. Material & method : To test the stability of the resonance frequency analyzer developed in this study, following methods and materials were used : 1) In-vitro study: the implant was placed in both epoxy resin of which physical properties are similar to the bone stiffness of human and fresh cow rib bone specimen. Then the resonance frequency values of them were measured and analyzed. In an attempt to test the reliability of the data gathered with the resonance frequency analyzer, comparative analysis with the data from the Periotest was conducted. 2) In-vivo study: the implants were inserted into the tibiae of 10 New Zealand rabbits and the resonance frequency value of them with connected abutments at healing time are measured immediately after insertion and gauged every 4 weeks for 16 weeks. Results : Results from these studies were such as follows : The same length implants placed in Hot Melt showed the repetitive resonance frequency values. As the length of abutment increased, the resonance frequency value changed significantly (p<0.01). As the thickness of transducer increased in order of 0.5, 1.0 and 2.0 mm, the resonance frequency value significantly increased (p<0.05). The implants placed in PL-2 and epoxy resin with different exposure degree resulted in the increase of resonance frequency value as the exposure degree of implants and the length of abutment decreased. In comparative experiment based on physical properties, as the thickness of transducer increased, the resonance frequency value increased significantly(p<0.01). As the stiffness of substances where implants were placed increased, and the effective length of implants decreased, the resonance frequencies value increased significantly (p<0.05). In the experiment with cow rib bone specimen, the increase of the length of abutment resulted in significant difference between the results from resonance frequency analyzer and the $Periotest^{(R)}$. There was no difference with significant meaning in the comparison based on the direction of measurement between the resonance frequency value and the $Periotest^{(R)}$ value (p<0.05). In-vivo experiment resulted in repetitive patternes of resonance frequency. As the time elapsed, the resonance frequency value increased significantly with the exception of 4th and 8th week (p<0.05). Conclusion : The development of resonance frequency analyzer is an attempt to standardize the quantitative measurement of stability of implant and osseointegration and compensate for the reliability of data from other non-invasive measuring devices It is considered that further research is needed to improve the efficiency of clinical application of resonance frequency analyzer. In addition, further investigation is warranted on the standardized quantitative analysis of the stability of implant.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.533-547
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• 1997

In periodontics, much progress was made in the understanding of periodontal disease from 1960s to 1980s and in prevention and management of periodontal disease since the end of 1980s. This presentation will discuss about the prevalence of periodontal disease, treatment need, and provision of periodontal treatment in Korea, and how we could manage the periodontal disease efficiently in the future. According to an epidemiological study in Korea, periodontal disease(including gingivitis) was present in 82% of general population and periodontitis in 30-40% in adult population over 30y and juvenile periodontitis in 0.1% of adolescents. If we consider that at least 17% of these patients may have recurrent or refractory forms, there is obviously an abundance of disease that needs treatment, As a result of increase in life expectancy, senile population over 65 y will be increased from 6% in 1996 to 6.9% in 2000, and tooth retention rate and periodontal treatment need are expected to increase. Periodontists need all the help they can get from the general dentists to control periodontal disease. As for provision, postgraduate course in periodontics started in 1957 in Korea and produced over 700 specialized dentists in periodontics. One report indicated that the periodontists as well as general practitioners did periodontal therapy on only a few periodontal patients, because of specific control by current medical insurance system in Korea. Comprehensive periodontal examination is rarely done in local dental clinic. Therefore, enhancement of periodontal care in medical insurance system and education of simplified periodontal examination such as Periodontal Screening & Recording will make dentists diagnose and manage the management of adult patients is based on the recognition that there are multiple diseases, including gingivitis, chronic adlt periodontitis, and other more aggressive forms of periodontitis, and requires the earliest possible recognition of these three disease categories. In this presentation, we discuss practical approach using PSR to diagnose, manage and refer the patients, to facilitate the separation of the simple from the complex and the predictable from the unpredictable form of periodontal diseases and to integrate diagnostic and therapeutic techniques into private practice today.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.125-135
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• 2009

Statement of problem: Loosening or fracture of the abutment screw is one of the common problems related to the dental implant. Generally, in order to make the screw joint stable, the preload generated by tightening torque needs to be increased within the elastic limit of the screw. However, additional tensile forces can produce the plastic deformation of abutment screw when functional loads are superimposed on preload stresses, and they can elicit loosening or fracture of the abutment screw. Therefore, it is necessary to find the optimum tightening torque that maximizes a fatigue life and simultaneously offer a reasonable degree of protection against loosening. Purpose: The purpose of this study was to present the influence of tightening torque on the implant-abutment screw joint stability with the 3 dimensional finite element analysis. Material and methods: In this study, the finite element model of the implant system with external butt joint connection was designed and verified by comparison with additional theoretical and experimental results. Four different amount of tightening torques(10, 20, 30 and 40 Ncm) and the external loading(250 N, $30^{\circ}$) were applied to the model, and the equivalent stress distributions and the gap distances were calculated according to each tightening torque and the result was analyzed. Results: Within the limitation of this study, the following results were drawn; 1) There was the proportional relation between the tightening torque and the preload. 2) In case of applying only the tightening torque, the maximum stress was found at the screw neck. 3) The maximum stress was also shown at the screw neck under the external loading condition. However in case of applying 10 Ncm tightening torque, it was found at the undersurface of the screw head. 4) The joint opening was observed under the external loading in case of applying 10 Ncm and 20 Ncm of tightening torque. 5) When the tightening torque was applied at 40 Ncm, under the external loading the maximum stress exceeded the allowable stress value of the titanium alloy. Conclusion: Implant abutment screw must have a proper tightening torque that will be able to maintain joint stability of fixture and abutment.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.28-40
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• 2010

Purpose: The aim of this retrospective study was to provide long-term data about the correlation between multifactorial local factors and the survival of implants. Material and methods: During 19 years (1991 to 2009), 2796 implants were placed in 879 patients. From dental charts and radiographs, the following data were collected: patient's age at implant placement, gender, implant system, surface, length, diameter, location of implant placement, bone quality, primary stability, type of prosthesis. The correlations between these data and implant survival were analyzed. Statistical analysis was performed using Kaplan-Meier survival analysis, Chi-square test, odds ratio. Results: 1. Among the 2796 implants, 150 implants failed that resulted in a cumulative survival rate of 94.64%. The cumulative survival rate of smooth surface implants (91.76%) was lower than rough surface implants (96.02%). 2. Anatomic location, implant surface, diameter of smooth surface implant, primary stability, type of prosthesis, patient's age and gender were significantly associated with implant survival (P < .05). 3. No significant difference in implant survival was found in relation to the following factors: implant length, bone quality, diameter of rough surface implants and type of rough surface according to implant manufacturer (P < .05). Conclusions: Local factors such as anatomic location, implant surface, diameter of smooth surface implant, primary stability and type of prosthesis have a significant effect on implant survival.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.215-221
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• 2009

Statement of problem: Recently the populations of patients receiving implant surgery are greatly increase for maintaining oral health. Purpose: This study was conducted for implanted patients to assess the chewing ability patient satisfaction level and changes in quality of life before and after the implant surgery. Material and methods: The current study subjected 109 adult patients, older than 20 years of age, who received implant surgery from December, 2006 to October, 2007 at the 6 dental clinics located at Daegu and Ulsan metropolitan cities. Twice of surveys were conducted for the patients before and after receiving the dental implant surgery. Results: As the motivation of receiving implant surgery, 45.9% of the patients selected the surgery for the chance o "f chewing function recovery", and " failure of treatment and complications" was found to be the most worrisome at the time of surgery by recording 38.5%.The satisfaction level before the implant surgery scored 30.37, while the score was increased to 45.01 after the surgery by showing a significant difference before and after receiving the surgery(P<.001). Regard on the surgery, 91.8% of the patients responded as "Satisfy", and 89% of the study subjects responded that they have willingness to recommend the surgery to their families and friends. The chewing ability score measured by using the surveys on edible foods, the score before the surgery was 15.24, while the score was increased to 19.11 after the surgery by showing a significant difference before and after receiving the surgery(P<.001). The quality of life score was also found to be increased to 11.17 after the surgery from 9.99 before the surgery by showing a significant difference(P<.001). Conclusion: In a future, the studies on the numbers of implanted loss teeth and the location of tooth loss are necessary, more long-term follow study are needed, and it is thought to be necessary to enlarge the sample size of subjects in conducting the studies.