• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.3
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• pp.195-204
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• 2011

Introduction: This study examined the regulatory mechanism underlying the meal-induced changes in the hypothalamic-pituitary-adrenal gland (HPA) axis activity. Materials and Methods: Male Sprague-Dawley rats (250-300 g) were hired for two different experiments as follows; 1) rats received either 8% sucrose or 0.2% saccharin ad libitum after 48 h of food deprivation with the gastric fistula closed (real feeding) or opened (sham feeding). 2). rats received 5 ml of intra-oral infusion with 0.2% saccharin or distilled water after 48 h of food deprivation. One hour after food access, all rats were sacrificed by a transcardiac perfusion with 4% paraformaldehyde. The brains were processed for c-Fos immunohistochemistry and the cardiac blood was collected for the plasma corticosterone assay. Results: Real feedings with sucrose or saccharin and sham feeding saccharin but not sucrose, following food deprivation decreased the plasma corticosterone level. c-Fos expression in the nucleus tractus of solitarius (NTS) of the fasted rats was increased by the consumption of sucrose but not saccharin, regardless of the feeding method. On the other hand, the consumption of sucrose or saccharin with real feeding but not the sham, induced c-Fos expression in the paraventricular nucleus (PVN) of the fasted rats. The intra-oral infusion with saccharin or water decreased the plasma corticosterone level of the fasted rats. Intra-oral water infusion increased c-Fos expression in both the PVN and NTS, but saccharin only in the NTS in the fasted rats. Conclusion: Neither restoration of the fasting-induced elevation of plasma corticosterone nor the activation of neurons in the PVN and NTS after refeeding requires the palatability of food or the post-ingestive satiety and caloric load. In addition, neuronal activation in the hypothalamic PVN may not be an implication in the restoration of the fasting-induced elevation of the plasma corticosterone by oropharyngeal stimuli of palatable food.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.467-475
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• 1998

악안면 영역에 동통이 가하여지면 회피반사의 일종인 개구반사가 유발되며, 개구반사의 크기는 뇌간의 중추에 전달된 동통의 크기에 비례한다. 따라서 동통의 정도를 악이복근의 근전도를 이용하여 정량화 할 수 있고 동통의 지표로 이용할 수 있다. 본 실험은 악안면동통에 의하여 유발된 개구반사의 크기가 침점(족삼리) 전기자극으로 감소되는지와 이러한 전기침의 효과가 나타나는데 opioid 물질이 관여하는지에 대하여 연구하고자 하였다. 8주 이상, 150g이상의 Sprague-Dawley계 쥐 34 마리를 암수 구별없이 이용하여 실험하였다. 복강 내 Urethane용액(1.5g/kg)을 주입 전신마취하고 악이복근을 노출시켜 근전도 기록을 위한 한쌍의 선전극을 삽입하였다. 동통유발을 위하여 구강내 하악 이공주변에 0.1mm의 선전극을 한쌍 삽입하고 전기자극기에 연결하였다. 유해자극 조건은 duration $100{\mu}sec$, interval 5sec의 pulse로 정하고 자극의 크기는 개구반사를 일으키는 역치의 2배 크기로 하며 매 측정시마다 동일 자극을 10회식 가하여 평균하였다. 침점의 전기자극을 위하여 침점의 하나인 족삼리(Zusanli)에 표면전극(넓이 $0.4cm^2$ 정도)을 부착하고 자극부위가 약한 근수축을 일으키는 강도인 $100{\mu}sec$, 5V, 2Hz의 자극을 20분간 가하였다. 악이복근의 근전도는 교류증폭기 (Dam80, WPI, USA) 에서 1000배 증폭하여 유해자극이 가해진 순간 oscilloscope 에서 관찰하여 그 크기를 측정하였다. 침점의 전기자극으로 나타나는 진통효과가 opioid의 분비와 관련있는지 알아보기 위하여 opioid 의 길항제인 naloxone(0.2mg/kg)을 복강 내로 투여하였다. 실험군을 4군(group I - IV)으로 분류하였고 각 군에서 근전도를 측정한 단계는 다음과 같다. group I : control 침점에 전기자극 20 분간 가한후(EA), 20분후(EA20) group II : control 침점에 전기자극 20분간 가한후(EA), naloxone 투여 20분후(NX) group III : control naloxone 투여 5분후 침점에 전기자극 20분 가한후(NxEA20) group IV : control naloxone 투여 20분후(NX20) 구강내에 가해진 유해자극에 의하여 발생하는 악이복근 근전도는 족삼리 침점의 전기자극으로 그 크기가 감소하였고 이러한 침점자극의 효과는 naloxone의 투여로 인하여 억제되었다. 이와 같은 결과는 침점자극으로 진통작용이 나타나는데에 opioid 물질이 관여하고 있음을 시사한다.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.1
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• pp.64-71
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• 2024

The most critical aspect of full-arch prosthodontic treatment is evaluating whether the patient's vertical occlusal dimension is appropriate, and if necessary, restoring it through increasing vertical dimension. If the vertical occlusal dimension is too low, it can lead to reduced chewing efficiency, as well as not only aesthetic concerns but also potential issues like hyperactivity of muscles and posterior displacement of the mandible. This report is about the patient dissatisfied with pronunciation and aesthetics due to an inappropriate vertical occlusal dimension resulting from prior prosthetic interventions, underwent full-arch prosthodontic restoration treatment. Through the utilization of digital diagnostic apparatus, a comprehensive evaluation was undertaken for patient's vertical occlusal dimension, occlusal plane orientation, and the condition of prosthetic restorations. Through 3D facial scanning, the facial landmarks were discerned, and subsequently, the new occlusal plane was established. This provided the foundation for a digitally guided diagnostic wax-up. An elevation of 5 mm from the incisor was determined. Comprehensive dental rehabilitation was then executed for all remaining teeth, excluding the maxillary four incisors. The treatment protocol followed a systematic approach by initially creating implant-supported restorations on both sides of the dental arch to establish a stable occlusal contact. Subsequently, prosthetic restorations for the natural dentition were generated. Diagnostic and treatment planning were established through the utilization of facial scanning. This subsequently led to a reduction in treatment complexity and an expedited treatment timeline.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.1
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• pp.53-64
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• 2008

Statement of problem: Peri-implant marginal bone loss is an important factor that affects the success of implants in esthetics and function. Various efforts have been made to reduce this bone loss by improving implant design and surface texture. Previous studies have shown that early marginal bone loss is affected by implant neck designs. Purpose: The purpose of this study was to examine the influence of laser microtexturing of implant collar on peri-implant marginal bone loss. Materials and methods: Radiographical marginal bone loss was examined in patients treated with implant-supported fixed partial dentures. Marginal bone level was examined with 101 implant fixtures installed in 53 patients at three periods(at the time of implantation, prosthetic treatment and 6-month after loading). Four types of implants were examined. The differences of bone loss between implants(ITI standard) with enough biologic width and implants(ITI esthetic plus, Silhouette IC, Silhouette IC Laser-$Lok^{TM}$) with insufficient biologic width have been compared. Resorption angles were examined at the time of prosthetic delivery and 6-month after loading. Results and Conclusion: Within the limitation of this study, the following results were drawn. 1. The marginal bone loss of ITI standard and Silhouette IC Laser-$Lok^{TM}$ was less than that of ITI esthetic plus and Silhouette IC(P<0.05). The marginal bone loss between ITI standard and Silhouette IC Laser-$Lok^{TM}$ had no significant statistical difference(P>0.05). There was no significant statistical difference between marginal bone loss of ITI esthetic plus and Silhouette IC(P>0.05). 2. There was no significant difference in marginal bone loss between maxilla and mandible(P>0.05). 3. There was no significant difference in resorption angle among four types of implants(P>0.05). The marginal bone of implants with supracrestal collar design of less than that of biologic width had resorbed more than those with sufficient collar length. The roughness and laser microtexturing of implant neck seem to affect these results. If an implant with collar length of biologic width, exposure of fixture is a possible complication especially in the anterior regions of dentition that demand high esthetics. Short smooth neck implant are often recommended in these areas which may lack the distance between microgap and the marginal bone level. In these cases, the preservation of marginal bone must be put into consideration. From the result of this study, it may be concluded that laser microtexturing of implant neck is helpful in the preservation of marginal bone.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.4
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• pp.214-219
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• 2019

Purpose: The aim of this study was to evaluate the correlation between inter-condylar width and inter-maxillary first molar width to present the criteria for prosthetic reconstruction of dental arch width in maxillary and mandibular fully edentulous patients. Materials and Methods: 120 Koreans (60 males and 60 females) who underwent the cone beam computerized tomography (Cone-beam CT) were selected. The Cone-beam CT images were analysed using Invivo 5.1. After reorientation of axis, inter-maxillary first molar width was measured by clicking both mesio-buccal cusp tip of maxillary first molar. And inter-condylar width was measured by clicking both middle points of condyles. The collected data were analysed with SPSS Version 20.0 and statistical significance of the correlation between inter-condylar width and inter-maxillary first molar width was verified by Pearson's correlation analysis. Results: The mean inter-condylar width of Korean was 105.9 mm, and that of male (108.3 mm) was statistically significantly wider than the female (103.4 mm). The inter-maxillary first molar width of Korean was 57.1 mm, and that of male (57.9 mm) was statistically significantly wider than the female (56.2 mm). Pearson's correlation analysis between inter-condylar width and inter-maxillary first molar width showed a Pearson correlation coefficient of 0.614 and statistically significantly positive correlation. Conclusion: Intercondylar width and inter-maxillary first molar width showed positive correlation and the average ratio of inter-condylar with and inter-maxillary first molar width was 1:0.54. Based on the results of this limited study, inter-condylar width can be used as a guide for setting up dental arch width in fully edentulous patient.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.570-593
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• 1996

This study was intended to perform the influence of condyle positional change after surgical correction of skeletal Class III malocclusion after BSSRO in 20 patients(males 9, females 11) using computed tomogram that were taken in centric occlusion before, immediate, and long term after surgery and lateral cephalogram that were taken in centric occlusion before, 7 days within the period intermaxillary fixation, 24hour after removing intermaxillary fixation and long term after surgery. 1. Mean intercondylar distance was $84.45{\pm}4.01mm$ and horizontal long axis of condylar angle was $11.89{\pm}5.19^{\circ}$on right, $11.65{\pm}2.09^{\circ}$on left side and condylar lateral poles were located about 12mm and medial poles about 7mm from reference line(AA') on the axial tomograph. Mean intercondylar distance was $84.43{\pm}3.96mm$ and vertical axis angle of condylar angle was $78.72{\pm}3.43^{\circ}$on right, $78.09{\pm}6.12^{\circ}$on left. 2. No statistical significance was found on the condylar change(T2C-T1C) but it had definitive increasing tendency. There was significant decreasing of the distance between both condylar pole and the AA'(p<0.05) during the long term(TLC-T2C). 3. On the lateral cephalogram, no statistical significance was found between immediate after surgery and 24 hours after the removing of intermaxillary fixation but only the lower incisor tip moved forward about 0.33mm(p<0.05). Considering individual relapse rate, mean relapse rate was 1.2% on L1, 5.0% on B, 2.0% on Pog, 9.1% on Gn, 10.3% on Me(p<0.05). 4. There was statistical significance on the influence of the mandibular set-back to the total mandibular relapse(p<0.05). 5. There was no statistical significance on the influence of the mandibular set-back(T2-T1) to the condylar change(T2C-T1C), the condylar change(T2C-T1C, TLC-T2C) to the mandibular total relapse, the pre-operative condylar position to the condylar change(T2C-T1C, TLC-T2C), the pre-operative mandibular posture to the condylar change(T2C-T1C, TLC-T2C)(p>0.05). 6. The result of multiple regression analysis on the influence of the pre-operative condylar position to the total mandibular relapse revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condyalr head long axis angle, the more increasing of mandibular horizontal relapse(L1,B,Pog,Gn,Me) on the right side condyle. The same result was founded in the case of horizontal relapse(L1,Me) on the left side condyle.(p<0.05). 7. The result of multiple regression analysis on the influence of the pre-operative condylar position to the pre-operative mandibular posture revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condylar head long axis angle, the more increasing of mandibular vertical length on the right side condyle. and increasing of vertical lengh & prognathism on the left side condyle(p<0.05). 8. The result of simple regression analysis on the influence of the pre-operative mandibular posture to the mandibular total relapse revealed that the more increasing of prognathism, the more increasing of mandibular total relapse in B and the more increasing of over-jet the more increasing of mandibular total relapse(p<0.05). Consequently, surgical mandibular repositioning was not significantly influenced to the change of condylar position with condylar reposition method.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.157-168
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• 2008

Statement of problem: Over the past two decades, implant supported fixed prosthesis have been widely used. However, there are few studies conducted systematically and intensively on the splinting effect of implant systems in mandible. Purpose: The purpose of this study was to investigate the changes in stress distributions in the mandibular implants with splinting or non-splinting crowns by performing finite element analysis. Materials and methods: Cortical and cancellous bone were modeled as homogeneous, transversely isotropic, linearly elastic. Perfect bonding was assumed at all interfaces. Implant models were classified as follows. Group 1: $Br{{\aa}}nemark$ length 8.5mm 13mm splinting type Group 2: $Br{{\aa}}nemark$ length 8.5mm 13mm Non-splinting type Group 3: ITI length 8.5mm 13mm splinting type Group 4: ITI length 8.5mm 13mm Non-splinting type An load of 100N was applied vertically and horizontally. Stress levels were calculated using von Mises stresses values. Results: 1. The stress distribution and maximum von Mises stress of two-length implants (8.5mm, 13mm) was similar. 2. The stress of vertical load concentrated on mesial side of implant while the stress of horizontal load was distributed on both side of implant. 3. Stress of internal connection type was spreading through abutment screw but the stress of external connection type was concentrated on cortical bone level. 4. Degree of stress reduction was higher in the external connection type than in the internal connection type.