• 대한심미치과학회지
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• 제32권2호
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• pp.54-68
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• 2023

디지털 방법을 사용한 무치악의 임플란트 치료계획은 surgical guide design으로 구체화된다. Surgical guide를 제작할 때, 우리는 먼저 최종 보철의 형태를 가상공간에 구현한 후 이를 바탕으로 식립 계획을 구체화하게 된다. 그러나 완전무치악 환자는 치아배열의 기준이 없고 악간관계가 정립되어 있지 않아 최종 보철의 형태를 짐작하기 어려워 surgical guide를 만드는 데 어려움이 있다. 이때 기존의 만족스러운 총의치나 부분의치, 잔존치 등이 존재한다면 그 치아배열이 가상적인 최종 보철의 reference가 될 수 있다. 만약 이러한 reference가 부재하거나 만족스럽지 못하다면, 진단용 목적으로 총의치를 제작하되 이를 구내에서 검증하는 과정이 필요하다. 이러한 과정을 통해 surgical guide를 제작할지라도 구내 상황에 따라 implant의 위치가 계획한 것과 다르게 식립될 수 있으며, 만약 guide의 positioning이 잘못된다면 그 오차는 모든 implant의 위치를 변위시킬 수 있으므로 guide 수술이 오히려 재앙으로 다가올 수 있다. 본 기고에서는 치아 배열의 reference가 될 수 있는 자료들을 적절한 시기에 채득하여 이를 디지털 공간에 이전 및 통일된 좌표계로 정렬하는 방법에 대해 논의하고, 또한 이렇게 수립된 식립계획을 현실의 구강에 적은 오차로 이전 및 정렬하는 방법에 대해 소개하여 일관적이고 체계적인 무치악 가이드 디자인의 프로토콜 정립에 대해 의견 개진하려 한다.

• Imaging Science in Dentistry
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• 제44권3호
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• pp.221-227
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• 2014

Purpose: This study aimed to investigate the clinical anatomy of lower premolar roots in a Spanish population by using cone-beam computed tomography (CBCT), correlating findings with patient gender and tooth type. Materials and Methods: Using 70 CBCT images, we evaluated 126 healthy, untreated, well-developed lower premolars. The number and morphology of roots and root canals, and the foramina number were assessed. Results for gender and tooth type were compared using the chi-squared and ANOVA tests. Results: The average length of teeth and roots was significantly higher in men (p=0.00). All 126 premolars had a single root. One canal was found in 83.3% of the premolars, with no gender or tooth type differences; Vertucci configuration types I and V were the most prevalent. The first premolars showed significantly greater variability than the second premolars (p=0.03). A single apical foramen was found in 89.7% of the premolars, with no differences by tooth type. Women had a significantly higher prevalence of two apical foramina than men (p=0.04). Some degree of curvature was observed in 65% of the premolars, with no differences by gender or tooth type. A root angle of more than $20^{\circ}$ was found in 12.98% of the premolars, without any differences by gender or tooth. Conclusion: All premolars were single-rooted. One canal had the most prevalent morphology. More variability in canal anatomy was found in the first premolars. Curvatures greater than $20^{\circ}$ were found at less than 5 mm from the apex.

• 대한치과교정학회지
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• 제26권6호
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• pp.691-703
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• 1996

Three-dimensional finite element model was made from adult skull to find desirable direction of retraction force to treat skeletal class II malocclusion. The retraction force of 400g was applied to the first molar. The direction of the force application was $23^{\circ}$ downward, parallel, $23^{\circ}$ upward and $45^{\circ}$ upward to the occlusal plane. The stress distribution and the displacement within the maxilla were analyzed by three-dimensional finite element method. The findings obtained were as follows: 1. Maxillary first molar was displaced posteriorly and inferiorly in $23^{\circ}$ downward, parallel, $23^{\circ}$ upward retraction but it was displaced posteriorly and superiorly in $45^{\circ}$ upward retraction. 2. ANS, A point and prosthion were moved posteriorly and inferiorly and pterygomaxillary fissure was moved posteriorly and superiorly. Clockwise rotation of maxilla occurred when retraction force was applied. 3. The degree of clockwise rotation of maxilla was greatest when the force was applied $23^{\circ}$ upward to the occlusal plane and was least when the force was applied $23^{\circ}$ downward to the occlusal plane. 4. Large tensile stress appeared in maxillary first molar and alveolar bone and the infraorbital region of maxilla when the force was applied $23^{\circ}$ downward to the occlusal plane. Tensile stress was smaller as the direction of force move upward. 5. Large compressive stress was appeared in maxillary first molar and infraorbital region in $45^{\circ}$ upward case and large compressive stress occurred in the posterior part of maxilla as the retraction force was upward.

• 대한치과마취과학회지
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• 제14권1호
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• pp.57-62
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• 2014

Background: The aim of this study was to analyze outpatient anesthesia for dental treatment in handicapped patients with behavior disorder in order to use data for carrying out better and safe anesthetic management. Methods: The data were drawn from the 100 patients with behavior disorder who visited CNUDH dental clinic for disabled based on anesthesia record to investigate patient's systemic condition, cooperative level, anesthesia method according to patients cooperation, and side effects after recovery time. Results: Mental retardation (58%) is the most reason to choose general anesthesia. The methods of induction according to cooperative level are intravenous propofol injection in 22 cases and inhalation of sevoflurane in 78 cases. Induction time of anesthesia were within 10 seconds in cases of propofol induction and average $48.8{\pm}18.5$ seconds in cases of inhalation induction. The time spent on dental treatment was average $3.2{\pm}1.1$ hours. After the end of treatment, average time to move from unit chair to recovery bed, to recliner, and to discharge from hospital are $10.4{\pm}5.1$, $36.9{\pm}17.1$ and $72.4{\pm}16.0$ minutes, respectively. During recovery, there are nausea with 9%, vomiting with 4%, dizziness with 2%, finger injury with 1%. Conclusions: This study showed our successful anesthetic outcomes without any severe side effects or complications. Through this study, it will be used for safe anesthetic management as useful reference data.

• 치위생과학회지
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• 제19권4호
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• pp.213-219
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• 2019

Background: Smoking exerts an adverse effect on the periodontal tissue by reorganizing the ecosystem of oral microorganisms and is considered to be an important factor in the development of periodontal disease. Although cross-sectional studies on smokers and non-smokers have been attempted to investigate the microbial differences in periodontal oral cavity, only few studies have been conducted to investigate the changes in oral microorganisms during smoking cessation. The purpose of this study was to investigate the changes of bacteria in saliva and gingival crevicular fluid (GCF) over a period of one year among 11 smokers trying to quit smoking. Methods: Eleven smokers trying to quit smoking visited the clinic at baseline, two weeks, two months, four months, six months, and 12 months to give saliva and GCF samples. The amounts of 16S rRNA, Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum subsp. nucleatum, Streptococcus mutans, and Streptococcus sobrinus in saliva and GCF were quantified using real-time polymerase chain reaction TaqMan probe assay. The results were analyzed by nonparametric statistical analysis using Friedman test and Spearman correlation coefficient. Results: After cessation of smoking, the amounts of 16S rRNA corresponding to P. gingivalis, F. nucleatum, P. intermedia, and T. denticola in saliva decreased and then again increased significantly. The amount of F. nucleatum 16S rRNA in GCF decreased significantly after smoking cessation. Positive correlations were observed between 16S rRNA and F. nucleatum and between F. nucleatum and T. denticola in saliva and GCF. Conclusion: Even if the number of subjects in this study was small, we suggest that smoking cessation may reduce the total bacterial amount and F. nucleatum in GCF. However, the results regarding changes in the microbial ecosystem due to smoking or smoking cessation were inconsistent. Therefore, further in-depth studies need to be carried out.

• 대한치과의사협회지
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• 제47권8호
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• pp.479-486
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• 2009

Purpose: The aim of this study was to show the clinical results of combination of Nd-YAP (1340nm) laser therapy with conventional endodontic and periodontal treatment. Materials and Methods: Four patients with chronic advanced periodontitis and endodontic infection were treated with conventional treatment and Nd-YAP laser therapy. Occlusal adjustment and splinting were done for stabilization of the teeth with severe horizontal and vertical mobility. The protocol for periodontal treatment was followed as scaling and root planing, pocket irrigation with 3% $H_2O_2$ and exposure of Nd-YAP laser using 320${\mu}m$ optical fiber with 160mJ/pluse, 30Hz. The other protocol for endodontic treatment was followed as access opening, canal preparation by hand and rotary instrument, canal filling, and exposure of Nd-YAP laser using 200${\mu}m$ optical fiber with 200mJ/pluse, 10Hz and 180mJ/pluse, 5Hz which were used respectively for disinfection and canal filling. The assessments of probing depth, mobility, and radiography were made prior to and after treatment. Result: All of these four clinical cases showed good healing of periodontium, which presented decrease of mobility and pocket depth, and increase of bone regeneration and bone density on the radiography. Conclusion: The bactericidal effect of Nd-YAP laser would provide benefits for improving clinical results that are obtained from conventional therapy.

• 대한치과교정학회지
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• 제43권4호
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• pp.186-192
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• 2013

Objective: To analyze the fatigue resistance, debonding force, and failure type of fiber-reinforced composite, polyethylene ribbon-reinforced, and braided stainless steel wire lingual retainers in vitro. Methods: Roots of human mandibular central incisors were covered with silicone, mimicking the periodontal ligament, and embedded in polymethylmethacrylate. The specimens (N = 50), with two teeth each, were randomly divided into five groups (n = 10/group) according to the retainer materials: (1) Interlig (E-glass), (2) everStick Ortho (E-glass), (3) DentaPreg Splint (S2-glass), (4) Ribbond (polyethylene), and (5) Quad Cat wire (stainless steel). After the recommended adhesive procedures, the retainers were bonded to the teeth by using flowable composite resin (Tetric Flow). The teeth were subjected to 10,00,000 cyclic loads (8 Hz, 3 - 100 N, $45^{\circ}$ angle, under $37{\pm}3^{\circ}C$ water) at their incisoproximal contact, and debonding forces were measured with a universal testing machine (1 mm/min crosshead speed). Failure sites were examined under a stereomicroscope (${\times}40$ magnification). Data were analyzed by one-way analysis of variance. Results: All the specimens survived the cyclic loading. Their mean debonding forces were not significantly different (p > 0.05). The DentaPreg Splint group (80%) showed the highest incidence of complete adhesive debonding, followed by the Interlig group (60%). The everStick Ortho group (80%) presented predominantly partial adhesive debonding. The Quad Cat wire group (50%) presented overlying composite detachment. Conclusions: Cyclic loading did not cause debonding. The retainers presented similar debonding forces but different failure types. Braided stainless steel wire retainers presented the most repairable failure type.

• 한국융합학회논문지
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• 제6권4호
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• pp.153-159
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• 2015

우리나라의 구강보조인력 중 치과위생사 업무와 치과 근무 간호조무사의 업무가 상당히 겹쳐 있고, 진료실 내부로 치과기공사 및 병원코디네이터가 깊숙이 들어와 있어 각 직종간의 업무영역으로 인해 마찰을 빗고 있다. 그리하여 이러한 직종 간 명확한 업무의 구분과 업무범위에 대한 정책적 방안을 제시할 목적으로, 치과 병 의원에 근무하는 치과보조인력의 업무 실태에 대해서 치과위생사의 법정업무를 중심으로 한 10개의 업무를 빈도분석 및 분산분석을 이용하여 비교 제시하였다. 치과위생사의 법정 업무를 중심으로 한 10개의 업무 중 대표적인 항목 스켈링을 비교한 결과, 치과기공사가 9(75%)명, 간호조무사가 64(87.67%)명, 기타에 체크한 사람이 11(64.71%)명이 시행하고 있어, 치과위생사를 제외한 치과보조인력이 치과위생사의 법정고유 업무를 많이 시행하고 있는 것으로 나타났다. 따라서 치과의료기관이 필요한 인력을 충분히 갖추고, 구강보조인력의 역할과 업무범위에 대한 정책적 방안이 제시될 필요성이 권장된다.

• 한국산학기술학회논문지
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• 제13권12호
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• pp.5986-5992
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• 2012

본 연구는 치과위생사의 이직실태를 파악하고 이직에 영향을 주는 요인들을 분석하고자 수행하였다. 대한치과위생사협회 및 각 지회의 보수교육에 참여한 치과위생사를 대상으로 설문지와 설문조사의 안내문을 직접 배포하여 자기기입식으로 작성하게 하고 회수하였다. 불성실한 설문지를 제외하고 1,955명의 설문결과를 분석대상으로 하였다. 연구대상자의 일반적 특성에 따라 이직 경험현황, 이직 횟수, 이직 이유와 취업된 기관을 미 선택한 이유의 현황은 교차분석 하고, 카이검정으로 유의성을 확인하였다. 유의수준은 5% 이내에서 검증하였다. 이직 경험이 있는 치과위생사는 45.8%로 절반 수준이었고, 년 소득이 많을수록, 학력수준이 높을수록 근무경력이 많을수록 이직경험이 높게 나타났다. 이직횟수는 연령이 많을수록, 학력이 높을수록, 총 근무경력이 많을수록 그리고 기혼자일 경우 많았다. 이직요인은 야간업무나 업무영역 등 근무환경이 23.7%, 개인사유가 19.1%, 연봉 등 근무조건이 14.6% 순으로 높게 나타났다. 치과위생사의 직업수명을 연장하기 위한 다양한 대책마련이 필요하다고 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.229-237
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• 2014

Background: Dentists are typically the first professionals who are approached to treat ailments within the oral cavity. Therefore they should be well-equipped in detecting suspicious lesions during routine clinical practice. This study determined the levels of knowledge on early signs and risk factors associated with oral cancer and identified which factors influenced dentist participation in prevention and early detection of oral cancer. Materials and Methods: A survey on dentists' knowledge and their practices in prevention and early detection of oral cancer was conducted using a 26-item self-administered questionnaire. Results and Conclusions: A response rate of 41.7% was achieved. The level of knowledge on early signs and risk habits associated with oral cancer was high and the majority reported to have conducted opportunistic screening and advised patients on risk habit cessation. Factors that influenced the dentist in practising prevention and early detection of oral cancer were continuous education on oral cancer, age, nature of practice and recent graduation. Notably, dentists were receptive to further training in the area of oral cancer detection and cessation of risk habits. Taken together, the study demonstrated that the dental clinic is a good avenue to conduct programs on opportunistic screening, and continuous education in these areas is necessary to adequately equip dentists in running these programs. Further, this study also highlighted knowledge deficits and practice shortcomings which will help in planning and developing programs that further encourage better participation of dentists in prevention and early detection of oral cancer.