• 대한치과교정학회지
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• 제39권6호
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• pp.402-419
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• 2009

성장이 종료된 치성 또는 골격성 개방교합 환자를 치료하는 것은 매우 어려운 일이다. 전치부 개방교합 환자는 증가된 전안면고경, 상악 구치부의 과도한 수직성장, 큰 하악각 등의 특징을 지닌다. 이러한 증례에서 구치의 압하를 통한 개방교합의 해소는 좋은 치료전략이다. 본 연구는 교정용 미니임플란트를 이용하여 개방교합을 치료하고 성공적인 유지를 얻은 두 명의 환자에 대한 보고이다. 적절한 진단이 시행되고 교정용 미니임플란트 등의 장치를 이용한 치료기법을 적용하면 수술치료 없이 교정치료만으로 개방교합의 치료가 가능하며, 하악구치부에 posterior bite block을 추가한 가철식 유지장치 및 SFR이 개교환자를 위한 유지장치 또는 보조유지장치로 유용하게 사용될 수 있다는 결론을 얻었다.

• Journal of Oral Medicine and Pain
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• 제24권1호
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• pp.81-94
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• 1999

This study intends to find usefulness of the computer assisted dental identification in mass disaster. The variety of dental characteristics was investigated through the research of dental records of 508 adults. And a computer assisted simulation program was used to evaluate the selectivity of dental identification. Findings were as follows : 1. Combinations of dental characteristics were found 155 types. The most various dental characteristic was showed on the mandibular first molar. 99.0% of subjects had dental characteristics for dental identification. 2. The posterior teeth, in comparison with anterior teeth, showed higher selectivity in dental identification which was enhanced by information on the material, type and cavity of the restoration. 3. The variety of dental characteristics was mainly found on the combinations of missing tooth with the material, type and cavity of the restoration. 4. The computer assisted dental identification program, with informa- tion about one's tooth state, made individual identification possible when there was only a part of the teeth in a corpse. 5. The computer assisted dental identification had considerably high selectivity based on the variety of dental characteristics. And it was also performed faster and preciser than the existing identification methods. Based on the results of this study, there are various combinations of the feature of the tooth itself with dental characteristics caused by a certain type of treatment on the teeth. And using the computer assisted dental identification program based on this, dental identification can be more efficient economically and more useful than any other forensic identification methods.

• Journal of Oral Medicine and Pain
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• 제42권4호
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• pp.89-101
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• 2017

Purpose: The purpose of this study is to investigate the prevalence of temporomandibular disorders (TMDs) in children and adolescents, their characteristic contributing factors, the characteristic features of symptoms and symptoms, and the response to treatment. Methods: We studied the researches, that were the results of the searches for words such as temporomandibular disorder, TMD, children, adolescents, and juvenile through PubMed and DBpia. Results: According to a study conducted in Busan, the ratio of adolescents increased from 18.3% to 21% in 2008 compared to 2000, and the proportion of boys increased from 38.58% to 45.38%. One of the characteristic contributing factors for adolescents is the macrotrauma such as jaw trauma, vehicle accidents, sports, physical abuse, forceful intubation, and third molar extraction. The second is a microtrauma from parafunctional habit such as bruxism, clenching, hyperextension, wind instrument, and fingernail biting that can cause joint overload, cartilage breakdown, synovial fluid alterations, and other changes within the joint. The diagnosis of TMDs in juvenile adolescents is not significantly different from that of adults. Medical history, clinical examination and radiological examinations are required. Conclusions: In the temporomandibular joint history and assessment, all comprehensive dental history examination is required, including head and neck pain, mandibular dysfunction, previous orofacial trauma, history of present illness with an account of current symptoms. For the treatment and management of temporomandibular arthritis in juvenile adolescents, understanding the characteristics of TMDs in juvenile adolescents and thoroughly analyzing appropriate diagnosis and possible contributing factors through comprehensive history taking & examination, conservative treatment, including fast and active cautions education, will be essential.

• 대한치과보철학회지
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• 제36권2호
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• pp.293-301
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• 1998

The purpose of this study was to investigate the effects of load on root that was applied to edentulous area in three simulated situation, in each case the guiding planes of abutment were right vertical, 95 degrees, or 100 degrees to residual ridge. The 2-dimensional finite element method was used and the finite element model was prepared as fellows. Right mandibular 1st and 2nd molar was lost and the 2nd premolar with distal rest was used as primary abutment which had three different degrees of guiding plane. Then 150N of compressive force was applied to central fossae of the 1st and 2nd molars and von Mises stress and displacement was measured. The results were as follows; 1. Irrespective of slopes of guiding planes, the stress was concentrated on mesial side of root apex and distal side of coronal portion of root, in particular on junction with distal alveolar bone. As slopes of guiding planes were increased. stress on root and compact bone surrounding abutment was increased but no considerable effect was seen on compact bone of residual ridge. 2. Distal side of coronal portion of root limited by periodontal ligament was displaced distally and mesial side of apical portion was mesially. With slope of guiding plane increasing, the pattern of displacement was similar with one another but the quantity was increased. 3. Both abutment & alveolar bone were displaced downward and root of abutment, especially distal side of coronal portion, was displaced severely. As the guiding plane was tiffed more mesially over $90^{\circ}$, the degree of displacement was also increased.

• Imaging Science in Dentistry
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• 제31권1호
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• pp.35-42
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• 2001

Purpose: To evaluate the usefulness of fractal analysis for diagnosis of periodontitis. Materials and Methods : Each 30 cases of periapical films of male mandibular molar were selected in normal group and patient group which had complete furcation involvement. They were digitized at 300 dpi, 256 gray levels and saved with gif format. Rectangular ROIs (10×20 pixel) were selected at furcation, interdental crest, and interdental middle 1/3 area. Fractal dimensions were calculated three times at each area by mass radius method and were determined using a mean of three measurements. We compared fractal dimensions at furcation and interdental crest area of normal group with those of patient group. And then we compared ratio of fractal dimensions at furcation area, interdental crest area to interdental middle 1/3 area. Results: Fractal dimension at interdental crest area of normal group was 1.979±0.018 and that of patient group 1.971±0.012 (p>0.05). Fractal dimension at furcation area of normal group was 1.986±0.024 and that of patient group 1.974±0.015 (p<0.05). The ratio of fractal dimension at interdental crest area to interdental middle 1/3 of normal group was 1.003±0.015 and that of patient group 0.993±0.018 (p<0.05). The ratio of fractal dimension at furcation area to interdental middle 1/3 of normal group was 1.006±0.018 and that of patient group 0.994±0.018 (p<0.05). Conclusion : The ratio of fractal dimension at interdental crest and furcation area to interdental middle 1/3 area showed a statistically significant difference between normal and patient group. In conclusion, it is thought that fractal analysis might be useful for the diagnosis of periodontitis.

• The Journal of Advanced Prosthodontics
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• 제4권3호
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• pp.162-169
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• 2012

PURPOSE. Fracture of the veneering material of zirconia restorations frequently occurs in clinical situations. The purpose of this in vitro study was to compare the fracture strengths of zirconia crowns veneered with various ceramic materials by various techniques. MATERIALS AND METHODS. A 1.2 mm, $360^{\circ}$ chamfer preparation and occlusal reduction of 2 mm were performed on a first mandibular molar, and 45 model dies were fabricated in a titanium alloy by CAD/CAM system. Forty-five zirconia copings were fabricated and divided into three groups. In the first group (LT) zirconia copings were veneered with feldspathic porcelain by the layering technique. In the second group (HT) the glass ceramic was heat-pressed on the zirconia coping, and for the third group (ST) a CAD/CAM-fabricated high-strength anatomically shaped veneering cap was sintered onto the zirconia coping. All crowns were cemented onto their titanium dies with Rely $X^{TM}$ Unicem (3M ESPE) and loaded with a universal testing machine (Instron 5583) until failure. The mean fracture values were compared by an one-way ANOVA and a multiple comparison post-hoc test (${\alpha}$= 0.05). Scanning electron microscope was used to investigate the fractured interface. RESULTS. Mean fracture load and standard deviation was $4263.8{\pm}1110.8$ N for Group LT, $5070.8{\pm}1016.4$ for Group HT and $6242.0{\pm}1759.5$ N for Group ST. The values of Group ST were significantly higher than those of the other groups. CONCLUSION. Zirconia crowns veneered with CAD/CAM generated glass ceramics by the sintering technique are superior to those veneered with feldspathic porcelain by the layering technique or veneered with glass ceramics by the heat-pressing technique in terms of fracture strength.

• 대한소아치과학회지
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• 제29권2호
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• pp.237-242
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• 2002

Lowe 증후군 또는 안뇌신증후군(oculocerebrorenal syndrome)은 X-염색체와 관련된 유전성 질환으로 반성열성유전양상을 나타낸다. 선천성 백내장과 녹내장 등의 안 증상, 근긴장 저하 건반사감소 등의 근신경계 증상, 신장 기능이상이 가장 특징적인 임상 증상이며, 이외에도 정신 지체, 성장지연, 전두부 융기, 가늘고 성긴 모발, 돌출된 귀, 골질환 등이 발생할 수 있다. Lowe 증후군 환자는 정신지체로 인해 치과치료시 전신마취하에서의 처치가 요구되나, 대사성 산증, 악성고열의 발생위험과 사용약제에 의한 부작용 등이 위험요소로 작용할 수 있으므로, 필요한 경우 내과 또는 소아과 의료진이 참여된 협진체제 하에서 가능한 짧은 시간 진행되어야 한다. 이러한 치과적 처치의 어려움으로 Lowe 증후군 환자에서 치과질환의 예방이 좀더 강조되어야 하면, 이를 위해 보호자의 주위의 적극적 관리가 요구된다.

• 대한소아치과학회지
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• 제40권1호
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• pp.11-20
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• 2013

치아침식증의 유병률은 어린이에서 증가추세에 있고 전 세계적인 관심 또한 증가하고 있으나, 우리나라에서는 이에 대한 연구적, 임상적 관심이 아직 미미한 수준이다. 본 연구는 탈락에 근접한 최종 단계의 유구치 침식의 유병률과 심도, 그리고 이와 관련된 위험인자를 조사할 목적으로 수행되었다. 788명의 어린이를 대상으로 구강 검진을 시행하였다. Modified Linkosalo & Markkanen system을 이용하여 침식성 병소를 분류하였고, 보호자를 대상으로 침식성 음식과 음료 섭취의 빈도와 소비 방법에 관련된 정보를 포함한 설문 조사를 시행하였다. 그 결과 231명(27%)의 어린이에서 치아침식증이 관찰되었고, 하악좌측제1유구치에서 가장 호발하였다. 위험인자 분석에 따르면 잦은 탄산음료와 과일주스에서 섭취 빈도는 침식의 발생과 유의한 관련성이 있었고(p < 0.05), 빨대를 이용해서 과일주스를 섭취할 때 유의하게 침식 발생이 감소하였다(p < 0.05).

• 구강회복응용과학지
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• 제25권1호
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• pp.1-12
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• 2009

이 논문의 목적은 시멘트 층 내의 응력분포에 대해 금관의 물성과 시멘트의 물성 및 교합력의 방향이 미치는 영향을 이차원 유한요소분석으로 조사하는 것이다. Chamfer 변연을 가지는 23개의 하악 제1대구치 모델을 상정하였다. 금관의 재질은 제 3형 금합금, Ni-Cr 합금, 세라믹, 복합레진 등 4가지이며, 시멘트의 재질은 인산 아연 시멘트와 글라스 아이오노머 시멘트 등 2가지이다. 치축과 평행하게 또는 경사지게 하여 1N 단위로 금관에 하중을 가했다. 시멘트층의 응력은 금관 변연이 다른 곳보다 더 높았다. 치축에 평행한 하중이 치축에 경사진 하중보다 더 높은 응력을 발생시켰다. 경도가 더 큰 금관은 시멘트 층 내에서 더 높은 응력을 나타냈으며, 더 높은 응력은 더 큰 Young's modulus을 나타냈다.

• 대한치과기공학회지
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• 제40권2호
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• pp.63-69
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• 2018

Purpose: The purpose of this study is to investigate the non-precious metal core materials used in the dental laboratory to fabricate the implant superstructure by CAD / CAM method. And to observe and compare the morphology and distribution of the osteoblasts in relation to implant osseointegration. Methods: In this study, the mandibular right first molar tooth model was selected as an international standard to produce a single core. Using this model, the impression was made with the silicone rubber, the tooth model was scanned, and a single core was designed and 5-axis milling was performed. The materials used were Cobalt-Chromium and Nickel-Chromium, and the cores for dental implant top structures were fabricated according to the procedures of the dental labs. After the fabrication, the marginal area of the core was separated and cell culture experiment was performed. The osteoblast cells used MC3T3-E1, which is currently widely used. For morphological analysis of osteoblasts, cells were posttreated and observed using CLSM (Confocal Laser Scanning Microscope) and compared. Results: The cell adhesion behavior of the specimen surface measured by CLSM was uniformly distributed in specimen A (Cobalt-Chromium) than in specimen B (Nickel-Chromium). The distribution and changes of the cells were different in the two specimens. Conclusion : It is possible to confirm that specimen A (Cobalt-Chromium) is suitable for the living body through adhesion and proliferation of osteoblasts related to implant osseointegration in the non-precious metal superstructure used after implantation. It is considered that it is preferable to use Co-Cr when fabricating the superstructure.