• 대한수학회논문집
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• 제20권4호
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• pp.861-873
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• 2005

In this paper we approximate a cylindrical helix by bi-conic and bi-quadratic Bezier curves. Each approximation method is $G^1$ end-points interpolation of the helix. We present a sharp upper bound of the Hausdorff distance between the helix and each approximation curve. We also show that the error bound has the approximation order three and monotone increases as the length of the helix increases. As an illustration we give some numerical examples.

• 대한치과의사협회지
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• 제16권5호통권108호
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• pp.395-399
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• 1978

The patient, 21 years and 3 months female, complained of protrusion of lower face. There was severe procumbency of upper & lower anterior teeth. Cephalometric analysis revealed that the anteroposterior jaw relationship was normal, but the teeth was foreward on their respective basal bones, so diagnosed as bimaxillary dental prognathism. The patient underwent extraction of four Ist premolar and was treated with multibanded & direct bonding system. After 14 months, She gained good interdigitation of buccal segment and attractive facial profile.

• 대한두개안면성형외과학회지
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• 제17권4호
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• pp.222-224
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• 2016

Epidermal cysts are intradermal or subcutaneous cystic tumors that frequently occur in the face, scalp, neck, and body trunk. Acquired cases of epidermal cyst commonly occur as a result of various surgical operations, chronic irritation, or trauma, all of which may trigger the occurrence of the invagination of squamous epithelium. A 57-year-old man presented with a palpable mass $7cm{\times}2cm$ in size in the upper lip. The patient had a 3-year history of wearing a denture to restore missing bilateral maxillary central and lateral incisors, accompanied by inflammatory findings on the buccal mucosa due to chronic lip irritation. The resected oval-shaped cyst had a size of $5.5cm{\times}3.0cm{\times}2.5cm$, and it was an encapsulated mass with a well-defined margin. The histopathology was typical of epidermal cyst. This case of a rare giant upper lip epidermal cyst in a patient wearing a denture may be of interest to clinicians.

• 치과방사선
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• 제28권2호
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• pp.491-503
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• 1998

A cystic compound odontoma in the maxillary sinus occurred in a 13-year-old boy. who had missing right upper third molar without having the history of extraction of the wisdom tooth. He complained nasal stuffiness. headache. and pain on the affected face. resembling any sign and symptoms of the maxillary sinus problems. The cystic compound. sized 2 x 1.5 cm in diameter was pedunculated and attached on the posterior wall of the right maxillary sinus and above the antral floor. The location of the compound odontoma in the maxillary sinus was confirmed after panoramic. waters. spiral tomographic. CT examinations and surgical exploration. Its location was on the medial. posterior. superior to the normal position of the maxillary third molar or the maxillary dental arch. The cystic odontoma in the maxillary sinus made the patient have the signs and symptoms of maxillary sinusitis. The cystic compound odontoma might be originated from the dental lamina of the missing upper right third molar. The 'V principle' of the upper jaw growth and the pneumatization process of the maxillary sinus could explain why the compound odontoma had peduncular shape and the location of odontoma was on the medial. superior to the normal position of the maxillary dental arch.

• Archives of Plastic Surgery
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• 제40권5호
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• pp.486-491
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• 2013

In performing upper blepharoplasty in the elderly, looking younger and keeping the eyelids harmonious with the rest of the face have to be achieved at the same time. The most important goal in upper blepharoplasty for aging is correcting the drooping upper eyelid skin, and in this process, the surgeon may or may not create a double eyelid fold. The pros and cons have to be fully discussed with the patient, but the author personally prefers creating a double fold unless the patient refuses, because it is efficient in correcting and preventing further drooping of the skin. In most patients, the brow is elevated to compensate for the drooping eyelid, and when the drooping is corrected, brow ptosis may ensue. The surgeon has to prepare for these consequences before performing the procedure, and estimate the exact amount of skin to be excised. In the elderly, the skin and the orbicularis oculi muscle is thin, with a decreased amount of subcutaneous fat and retro-orbicularis oculi fat, and in most cases, excision of the skin alone is enough to correct the deformity. Removing large portions of soft tissue may also prolong the recovery period. Unlike younger patients, the lower skin flap should not be stretched too much in the elderly, as it may create an aggressive looking appearance. A few wrinkles in the lower flap should remain untouched to create a natural look. In this article, the author's own methods of performing an aging blepharoplasty are described specifically, with a step-by-step guide and surgical tips.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.3.1-3.9
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• 2017

Background: The purpose of the study is to compare the effects on the pharyngeal airway space of skeletal anchored face mask with those of tooth-borne facemask. Methods: We used two types of facemask for maxillary protraction, the tooth-borne facemask (TBFM) and the skeletal anchored facemask (SAFM), and evaluated the effects of each facemask on the pharyngeal airway. Twenty-eight patients (mean age 10.3 years) were treated with the TBFM and 24 patients (mean age 11.2 years) were treated with the SAFM. Lateral cephalometric radiographs were taken before treatment (T1) and after treatment (T2) to assess changes in the dimensions of the upper airway. Statistical analysis was performed with independent t tests, matched t tests, Mann-Whitney U tests, and Kruskal-Wallis tests. Results: There were marked increases in upper airway dimensions in both groups following treatment, but the SAFM group had a significantly greater increase in airway dimensions than the TBFM group. Also, the SAFM subgroups showed more improved airway measurements than the TBFM subgroups in both the superior and inferior pharyngeal airways. Conclusions: SAFM is more effective than TBFM in increasing upper airway dimensions.

• Composites Research
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• 제30권2호
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• pp.132-137
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• 2017

본 연구에서는 카본/BMI 면재와 노멕스 허니콤 코어를 가지는 샌드위치 포팅 체결부의 다양한 설계변수에 대한 파손특성 연구를 수행하였다. 샌드위치 시편은 코어 높이, 면재 두께 및 밀도에 따라 총 6종류가 제작되었고, 이중 1종류의 시편에 대해 온/습도 효과를 보기 위해 환경 조건이 가해졌다. 시험 결과 밀도가 $64kg/m^3$ 코어를 제외한 모든 시편에서 코어의 전단좌굴이 초기 파손모드로 나타났으며, 이후 하중을 지지하다 윗면재 파손과 동시에 아랫면재에 볼트가 파고드는 파손형상이 나타났다. 하지만 밀도에 의해 높은 강성을 가지는 시편의 경우 초기 전단좌굴 발생 없이 윗면재와 코어의 계면파손에 의해 낮은 최대파손하중을 나타냈다. 샌드위치 시편의 환경적 영향 평가를 위해 수행된 ETW1($82^{\circ}C$, Wet)과 ETW2($177^{\circ}C$, Wet)의 경우 RTD($24^{\circ}C$, Dry) 조건과 확연히 다른 초기 파손모드를 보였으며, 동일한 습도조건 하에 온도가 상승된 ETW2는 ETW1보다 전단좌굴 하중이 약 18% 감소되는 경향을 보였다.

• 대한치과교정학회지
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• 제15권1호
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• pp.123-140
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• 1985

Variation in the facial pattern and effect of the rotational jaw growth on the facial proportion were studied in serial cephalometric radiographs of 40 Korean children (25 boys, 15 girls) ranging in age from 6 to 13 years. According to Y-axis (N-S-Gn) growth change during the 7 years of period, the subject who had exhibited 'wave-like' manner of Y-axis growth change within ${\pm}\;2^{\circ}$ was classified to the Parallelwise group and the subject who had exhibited Y-axis increase more than $+2^{\circ}$ was classified to the Clockwise rotation group and the subject who had exhibited Y-axis decrease more than $-2^{\circ}$ was classified to the Counterclockwise rotation group. For the comparison of each group, a total of 22 morphologic variables were employed and the data were analyzed by means of computer morphometrics and statistical methods. On the basis of the finding of this study, the following trends were established. 1. The Parallelwise group was $75\%$, the Clockwise rotation group was $12.5\%$ and the Counter-clockwise rotation group was $12.5\%$. 2. The growth pattern of cranial base was related to the rotation of mandible. 9. Maxillary prognathism was occured in the Counterclockwise rotation group and the rotation of palatal plane was occured in the Clockwise rotation group. 4. Mandibular prognathism was occured in the Parallelwise and the Counterclockwise rotation groups, especially in the Counterclockwise rotation group. 5. The degree of maxillo-mandibular divergency was constant in the Clockwise rotation group but decreased in the Counterclockwise rotation and the Parallelwise groups, especially in the Counterclockwise group. 6. There were no differences in the size of the anterior upper facial height (N-ANS) and the posterior lower facial height ((Go-Me)-PNS) but there were differences in the size of the anterior lower facial height (ANS-Me) and the posterior upper facial height ((S-N)-PNS) between each group. 7. The growth increment and the size of the facial depth was not related to the growth pattern of the face but the growth increment and the size of the facial height was related to the growth pattern of the face. 8. Proportional change due to the facial growth rotation was concentrated in the anterior lower face. 9. The most apparent difference between each group was happened in the size of the posterior cranial base (S-Ba) and the facial length (S-Gn).

• 한국컴퓨터정보학회논문지
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• 제27권10호
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• pp.185-193
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• 2022

본 연구는 성인 여성의 얼굴 유형에 적합한 마스크 패턴 개발을 위하여 시판되고 있는 다회용 마스크 패턴을 비교·분석하고자 하였다. 이를 통해 마스크 패턴 개발 및 생산업체에 필요한 자료를 제공하고자 하였다. 시판 다회용 마스크 패턴의 치수 및 형태를 비교한 결과, 성인용으로 제작된 L사이즈 마스크임에도 불구하고 치수에 있어서 큰 차이를 나타냈다. 가상착의에 대한 외관평가 결과 정면의 앞중심선의 수직, 마스크의 윗부분 감쌈과 여유, 코높이, 마스크 아랫부분의 감쌈과 여유에서 디자인별로 유의미한 차이가 있었다. 측면도 얼굴 옆부분의 감쌈, 옆부분의 여유, 끈 간격과 길이에서 유의미한 차이를 나타냈다. 외관평가 결과, 마스크4가 가장 좋은 평가를 받았다. 마스크 패턴의 형태는 코 아랫부분에 크게 다트가 있어 얼굴의 입체적인 형태를 커버할 수 있도록 되어 있으나 마스크에 따라 곡선의 정도와 각도에 차이를 나타냈다. 마스크 상부와 마스크 하부, 볼 부분은 밀착되지만, 코와 입 부분에는 여유가 있는 마스크 패턴의 평가가 높았다. 마스크 패턴은 얼굴형 및 치수에 대한 분석을 통해 마스크 상부길이와 하부길이, 코 높이에 따른 마스크 다트량의 설정이 이루어져야 할 것으로 생각된다.

• 재활치료과학
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• 제6권1호
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• pp.25-33
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• 2017

목적 : 본 연구는 작업치료사들을 대상으로 현재 시행하고 있는 뇌졸중 환자의 양측 상지 활동 훈련에 대한 현황 및 인식도를 조사하고자 한다. 연구방법 : 2016년 6월 한달동안 작업치료사 10명을 대상으로 설문조사를 실시하였다. 설문지는 대상자의 일반적 특성, 환자의 일반적 특성, 환자가 수행하기 어려운 양측 상지 활동, 훈련에 적용하는 양측 상지 활동, 치료에 적용시켜 보고 싶은 양측 상지 활동의 총 5개 영역을 포함하는 총 17개 문항으로 구성되었다. 결과 : 본 연구 결과 환자가 수행하기 어려운 양측 상지 활동은 못 박기였으며, 주로 훈련에 적용하는 양측 상지 활동은 컵 뚜껑 열기였다. 또한 치료에 적용해 보고 싶은 양측 상지 활동은 세수하기였다. 결론 : 본 연구를 통해 작업치료사가 양측 상지 훈련에 적용하는 활동 목록을 알 수 있었으며, 이는 향후 양측 상지과제를 선정할 때 기초자료로 유용하게 활용될 수 있을 것이다.