• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.37.1-37
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• 1981

Even through the methods of improving hearing are widely practiced in Korea, with its 30 years of history, there are many different opinions regarding the selection of surgical technique and the materials to be used in tympanoplasty. Also there are varying standards of postoperative evaluations. Therefore, we have done research to evaluate hearing improvement which in one of the objective of the middle ear surgery. The research was conducted for one year, January to December 1980. This research compared the level of hearing improvement after tympanoplasty, according to materials used in tympanoplasty and collumelization. Following are the data we have obtained; 1) Total number of cases we have reviewed were 306. Out of this, 35% of the cases were tympanoplasty type 1, 12.7% of the cases were collumelization with mastoidectomy, and 11.9% of the cases received collumelization without mastoidectomy. 2) We have conducted audiometry on 41.1% of the tympanoplasty type 1, 64.1% of the collumelization with mastoidectomy, and 45.7% of the collumelization without mastoidectomy. 3) We have observed above 11 dB hearing improvement in 70% of the tympanoplasty type 1, 36% of the collumelization with mastoidectomy, and 44% of the collumelization without mastoidectomy. 4) Over 11 dB decrease of air-bone gap in 61% of the tympanoplasty type 1,32% of the collumelization with mastoidectomy, and 63% of the collumelization without mastoidectomy. 5) If we look at the hearing improvement according to the materials used in the tympanoplasty, there was above 11 dB improvement of the air conduction in 63% with cartilage and 54% with fascia. In air-bone gap, 56% with cartilage and 52% with fascia. 6) If we look at the hearing improvement according to the materials used in the collumelization, there was above 11 dB improvement in 50% with cartilage, 14% with homograft, 55% with autograft. In air-bone gap, 56%, 21%, and 55% respectively.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.213-220
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• 2015

This research was study the accuracy of three-dimensional stereotactic breast biopsy, using a core Needle Biopsy and to assess the accuracy of Stereotactic biopsy and Sono guided biopsy. Using Stereotactic QC phantom to measure the accuracy of the 3D sterotactic machine. CT Scan and equipment obtained in the measured X, Y, Z and compares the accuracy of the length. Using Agar power phantom compare the accuracy of the 3D sterotactic machine and 2D ultrasound machine. Z axis measured by the equipment to compare the accuracy and reliability. Check the accuracy by using visual inspection and Specimen Medical application phantom. The accuracy of the 3D sterotactic machine measured by Stereotactic QC phantom was 100%. Accuracy as compared to CT, all of X, Y, Z axis is p > 0.05. The accuracy of the two devices was 100% as measured by Agar powder phantom. There was no difference between t he t wo d evices as C T and p > 0.05. 3D sterotactic machine of the ICC was 0.954, 2D ultrasound machine was 0.785. 2D ultrasound machine was different according to the inspector. Medical application phantom experiments in 3D sterotactic machine could not find the Sliced boneless ham. 2D ultrasound machine has not been able to find a small chalk powder group. The reproducibility of the three-dimensional stereotactic breast biopsy was better than effect of Sono guided biopsy.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.3
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• pp.288-295
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• 2019

Passive fit of prosthesis is an essential property of implant supported prosthesis for long term success and minimization of complications. And the property is determined mostly by fabrication procedure. There were limitations of extensive implant prosthesis because conventional casting method generate contraction error of long span prosthesis. However, Computer-aided design/Computer-aided manufacturing (CAD/CAM) technology of 3D printing and milling metal framework can overcome those limitations. This case is a full mouth rehabilitation using extensive implant fixed prosthesis. Removable interim prosthesis was made for esthetic, functional evaluation and a guide for implant insertion. After the insertion, implant fixed interim prosthesis was delivered. After additional evaluation and adjustment, final prosthesis was designed with CAD, the fabricated with CAM. Milling technique was used for anterior screw type implant superstructure and 3D printing technique was used for the anterior and posterior implant copings. Fit of the final restoration was favorable. The practitioner and patient were both esthetically and functionally satisfied with the final result.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.97-106
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• 2021

Dental implants should be placed at ideal sites for implant-supported restorations. For a patient with insufficient residual ridge, mouth preparation including surgical intervention can be indicated to establish a soft and hard tissue environment favorable for a definitive prosthesis. Prosthodontic design based on computer-guided surgery and computer-aided design-computer-aided manufacturing (CAD-CAM) provides a visual blueprint allowing a clinician to assess the necessity of such a surgical intervention beforehand. In this case, a definitive restoration was planned and made via a CAD-CAM system according to the patient's oral status before treatment, simulated surgical interventions and serial provisional restorations. Based on the planning, a guided template was made and the implants were installed with bone augmentation using the template. Customized abutments, the first and the second provisional restorations were designed and fabricated by CAD-CAM. The definitive restorations were digitally made following the shape of the second provisional prostheses, which were confirmed in the patient's mouth. The patient was satisfied with the masticatory, phonetic and aesthetic functions of these definitive prostheses.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.69-81
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• 2005

As one of the variations in growth and development of the craniofacial complex. malocclusion shows lack of concordance In the recognition and severity of malocclusion for dentists as well as the acceptance and need of orthodontic treatment for the patient The purposes of this study were 1) to examine the relationships between objective malocclusion severity aid subjective treatment difficulty. 2) to evaluate the effect of malocclusion components to the subjective perceived difficulty of treatment. 3) to establish the weighted values of malocclusion components to reflect the treatment difficulty 100 pairs of dental casts with the general characteristics of malocclusion. were selected from the orthodontic departments of Kyunghee University and Samsuug Medical Center. The severity of malocclusion was evaluated by the author with the PAR index The perceived treatment difficulty and the estimated treatment duration on these dental models were evaluated by 8 experienced orthodontists. The relationships between the objective malocclusion severity and the subjective treatment difficulty were statistically evaluated. and the weighted values of malocclusion components to reflect treatment difficulty were statistically formulated. There were significant relationships between objective malocclusion severity and subjective treatment difficulty The malocclusion components which significantly affected the treatment difficulty and their weighted values in parentheses were as follows upper anterior alignment(1). overbite (2). buccal occlusion (3) middline (4), and overjet (5). This study Provides the fundamental principle to evaluate the objective malocclusion severity which is reflected by the subjective treatment difficulty of Korean orthodontists.

• Journal of dental hygiene science
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• v.8 no.3
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• pp.183-187
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• 2008

The objective of this study was to assess the level of contamination of dental equipment surfaces by Staphylococcus aureus and to obtain basic information for the prevention against cross infection between students and outpatients. Human samples were collected by rubbing the oral cavity, anterior noses, and lip of students and outpatients with sterile cotton swabs. Environmental samples were collected from 11 sites at practical laboratory, 4 sites at seminar room, and 5 sites at sterilizing room before, during, and after clinical procedures. These samples were cultured on brain-heart infusion agar at $37^{\circ}C$ for 24 hours. Gram-stained and identified as S. aureus colonies were counted each period and these results were analyzed by t-test and ANOVA test. In human, oral cavity showed the greatest S. aureus counts and there were no statistically significant differences between students and outpatient. Practical laboratory revealed the greatest S. aureus among all environmental groups. The greatest number of S. aureus was observed during clinical procedures (P < 0.05) and light handles, chair head, and spittoon showed a high level of statistically significant differences. In conclusion, S. aureus was dispersed in human and dental clinical environment and increased their number during clinical procedures.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.513-519
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• 1999

Chloral hydrate is one of the most widely used sedative agents to control the difficult to treat young age group in the dental clinic. We are often frustrated to see the patient still awake and cry with agitation even after far more than the normal onset time. In such a case, the patient has to be rescheduled for another sedation visit with different agents and/or routes which greatly disappoints the guardians. This case report presents a sedative regimen that can possibly help the clinician complete scheduled treatment without postponement. We have tried sleep induction with Enflurane (1-1.5vol%) for 60 seconds to 37 patients of those who failed to respond properly to the dose(70mg/kg)of oral Chloral hydrate. The average age and weight of the patients was 34.3 months(22-43mo.) and 14.9kg(11-21kg) respectively. It is suggested that sleep induction with low dose Eflurane produced a stable state during dental treatment with respect to vital sign and behavior. Evidence of adverse effect was not detected or reported during and/or after the procedures.

• Korean Journal of Cleft Lip And Palate
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• v.3 no.1
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• pp.1-9
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• 2000

목적 : 치조파열 환자에 있어서 이차 치조골 이식술을 시행한 후 그 결과를 알아보고자 방사선학적 분석을 통하여 평가하였다. 본 연구의 목적은 수술전 골결손부 인접치아의 치조정 높이와 수술후 골결손부 인접치아의 치조정 높이를 근심측과 원심측에서 각각 측정함으로써 치조정의 높이가 과연 통계적으로 유의성 있게 증가하는지와 치조골 이식술의 성공률이 치조열의 너비와 상관관계가 있는지의 여부를 알아보는 것이다. 환자 및 방법 : 1991년부터 1999년까지 서울대학교병원 구강악안면외과에서 자가장골 채취 후 분쇄피질망사골 형태 또는 block 피질망상골 형태로 이식한 편측성 치조열을 가진 환자 중 최소한 6개월이 경과한 환자 56명을 연구대상으로 하였고 두 술자에 의해 시술되었다. 수술전 골결손부 인접치아의 치조정의 높이와 치조열의 너비 및 수술후 이식한 골의 높이와 절흔의 양은 치과용 파노라마 방사선 사진을 이용하여 측정하였고, 치조열의 너비는 모델이나 환자의 골결손부 근심치아의 근원심 폭경을 이용하여 환산하였다. 그리고 이식한 골의 높이와 절흔의 양을 1995년 Long이 제시한 방법으로 측정하여 술전의 측정치와 비교하였다. 결과 : 치조열의 너비는 평균 6.9mm(1.9mm-12.1mm) 였다. 근심에서의 치아는 골이식 당시 중절치가 52개(92.9%), 측절치가 4개(7.1%)였고, 49명의 환자에서 완전맹출을, 6명의 환자에서 부분맹출(측절치 2개, 중절치 4개)을 보였다. 원심측에서의 치아는 골이식 당시 측절치가 25개(44.6%), 견치가 29개(51.8%), 소구치가 2개(3.6%)였고, 완전 맹출이 32.1%, 부분 맹출이 57.2%, 미맹출이 10.7%로서 완전히 맹출하기 전에 골이식한 경우가 67.9%였다. 모든 환자에 있어서 bony bridge가 나타났고, 절흔이 인접치 아래로 연장되지 않았으며, 치조골 이식술 후 oronasal fistula를 보인 환자는 한 명도 없었으므로 성공률은 100%였다. 술후 근심측에서의 치조정의 높이는 근심측 치아 치근길이의 79%(평균), 원심측에서의 치조정의 높이는 원심측 치아 치근길이의 87%(평균)로서 통계적으로 유의성 있게 증가하였다. 결론: 이차 치조골 이식술을 시행한 후 치조정의 높이는 골결손부 근심측과 원심측에서 모두 유의성있게 증가하였고, 근심측에서보다 원심측에서 통계학적으로 더 유의성 있게 증가하였다. 치조열의 너비와 절흔의 양, 치조정의 높이 및 치조골이식 성공률과는 유의성 있는 관련성이 없었다.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.184-190
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• 2012

Purpose: The purpose of this study was to measure the absorbed dose and to calculate the effective dose for one periapical radiography using the portable and wall type dental X-ray machines. Materials and methods: Thermoluminescent chips were placed at 25 sites throughout the layers of the head and neck of a tissue-equivalent human skull phantom. The man phantom was exposed with the portable and wall type dental X-ray machines. For one periapical radiography taken by portable dental X-ray machine, the exposure setting was 60 kVp, 2 mA and 0.2 seconds, while for one periapical radiography taken by wall type dental X-ray machine, exposure setting was 70 kVp, 8 mA and 0.074 seconds. Absorbed dose measurements were performed and equivalent doses to individual organs were summed using ICRP 103 to calculate effective dose. Results: In the upper anterior periapical radiography using portable dental X-ray machine and in the lower posterior periapical radiography using both machines, the highest absorbed dose was recorded at the mandible body. The effective dose in upper anterior periapical radiography using portable and wall type dental X-ray machines was $4{\mu}Sv$, $2{\mu}Sv$, respectively. In the lower posterior periapical radiography, the effective dose for each portable and wall type dental X-ray machines was $6{\mu}Sv$, $2{\mu}Sv$. Conclusion: It was recommended that the operator use prudently potable dental X-ray machine because that the effective dose in the periapical radiography using wall type dental X-ray machine was lower than that in the periapical radiography using portable dental X-ray machine.

• Restorative Dentistry and Endodontics
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• v.35 no.6
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• pp.429-435
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• 2010

Objectives: The aim of this study was to investigate average working lengths of Korean posterior teeth and evaluate validity of endodontic file length. Materials and Methods: The endodontic working length of the posterior teeth of 670 Korean patients were measured than each mean value and standard deviation were investigated than the frequency deviation and standard deviation per each length were calculated. Results: Among the canals of premolar, 66.5% of canal length was marked under 20 mm by endodontic working length and 95.4% could be measured under 22 mm and Among the canals of molars, 95.5% of canal length was marked under 20 mm endodontic working length. Conclusions: With the result of measurement of endodontic working length of premolars of Korean, it suggested that 23 mm endodontic file is more proper than the 21 mm and 25 mm file on the market.