• 대한소아치과학회지
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• 제31권3호
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• pp.362-371
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• 2004

유치의 치근 흡수의 시기에 대한 정보는 소아치과 또는 교정과에서 진단 및 치료 계획의 수립에 중요한 역할을 제공하며, 치아의 발육 상태는 유전, 환경, 인종, 성별, 영양, 사회 경제적 상태 및 시대 변화에 따라 영향을 받는다. 본 연구의 목적은 현대 한국 아동의 유치 치근 흡수의 평균 연령을 측정하고, 1990년대 초와 2000년대 초의 유치 치근 흡수의 평균 연령을 비교하는 것이다. 경북대학교병원 소아치과에 내원한 $1990{\sim}1992$년의 1037명(여아 528명, 남아 509명) 및 $2001{\sim}2003$년의 1065명(여아 394명, 남아 671명)의 파노라마 사진을 대상으로 하여 횡적인 방법으로 조사하였다. 상악 치아 및 하악 전치부의 상의 선예도의 문제로 하악 유견치, 하악 제 1 유구치, 하악 제 2 유구치를 대상으로 하였다. 결과는 다음과 같다. 1. 유치 치근의 흡수는 2000년대 초 아동이 1990년대 초 아동에 비해 더 이른 시기에 흡수되는 경향을 보였으며 Res c 단계에서 평균 연령의 차이는 0.4년이었다. 2. Res c 단계에서 1990년대 초와 2000년대 초의 평균 연령의 차이는 여아에서 하악 유견치, 하악 제 1 유구치, 하악 제 2 유구치의 순으로 증가하였으며, 남아에서 하악 제 2 유구치. 하악 제 1 유구치, 하악 유견치의 순으로 증가하였다. 즉 평균 차이는 여아에서 나이 증가에 따라 증가하였으며, 남아에서는 나이 증가에 따라 감소하였다. 3. 1990년대 초와 2000년대 초 모두에서 여아가 남아에 비해 평균 0.3년 더 이른 시기에 흡수되는 경향을 보였다. 4. 하악 유견치의 치근 흡수의 시작은 하악 제 1 유구치 보다 늦었지만, 하악 유견치의 치근 흡수의 완료는 하악 제 1 유구치 보다 빨랐으며, 하악 유견치에서 치근 흡수에 소요된 총 기간은 가장 짧았다. 5. 치근 흡수의 속도는 흡수 말기가 초기에 비해 빠른 경향을 나타냈다. 정확한 유치 치근의 흡수시기에 대해 알기 위해서는 정기적이면서 종적인 연구가 필요하리라 생각한다.

• 대한소아치과학회지
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• 제24권3호
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• pp.487-494
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• 1997

It is rare to find multiple supernumerary teeth in individuals with no other associated diseases or syndromes. 'Non-Syndrome multiple supernumerary teeth' reviewed by Yusof(1990) have more frequency of occurrence in the mandibular region. Especially, mandibular premolar region appears to be the site of predilection for no n-syndrome multiple supernumerary teeth. Also, these may develop after most permanent teeth have erupted, thus their effect upon the occlusion is limited. In this case, the patient had 20 supernumerary teeth without other associated diseases or syndromes. All of the supernumerary teeth were impacted, and thirteen of them were found in the premolar region. In the radiographic and clinical finding, other specific complication resulted from the supernumerary teeth weren't observed.

• 대한치과교정학회지
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• 제6권1호
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• pp.17-24
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• 1976

The primary objective of this study was to define the differences that exist. between different sexes on the dentoskeletal framework and the soft tissue profile around the mouth. For the purpose of this study, cephalometric radiographs were obtained from the centric occlusion with closed lip position, through the research on each 42 males and females aged from 17 to 22 years with normal occlusion and acceptable facial appearence. The results were as follows: 1. Maxillary to mandibular relationships. Among the angles formed by the long axis of the maxillary and mandibular anterior teeth, the maxillary and mandibular anterior alveolar bone, and the lower and upper lips (Fig.2), only the angle formed by the lips was more acute in males than in females. The males have a more rounded profile, and the females have a flatter profile in the lower third of the face. The differences is statistically significant for the angle formed by the lips. The fact that the lips have a difference greater than that of teeth or the alveolar bone indicates that the lip position is not entirely due to tooth and bony support. Possibly the thickness of the lips has an influence. 2. Occlusal plane. The occlusal plane was related to the anterior tooth inclination, anterior alveolar bone profile, and the lip contour, both maxillary and mandibular (Fig.3). Only the angle related to lower lip was statistically significant. The females again had the more obtuse angle, indicating a flatter profile than that of the males. 3.Skeletal planes. The angles formed by the anterior maxillary lips, teeth, and alveolar bone with the Frankfort plane and the angles of the mandibular lips, teeth, and, alveolar bone and the mandibular plane were investigated (Fig.4). Results were similar to those from maxillary to mandibular relationships. The results were statistically significant for the upper lip and the lower lip, only. 4. Esthetics. The facial line and the mandibular plane were compared with the esthetic line. These angles were different for the different sexes, but only the latter was statistically significant. This difference may be due to the profile contour of the nose.

• 대한치과교정학회지
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• 제11권2호
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• pp.143-150
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• 1981

Casts of 180 Korean male and female with normal occulsion of early permanent dentition (from dental age of Hellman III C, to IV A) were studied to measure the mesiodistal crown diameters and to calculate the coefficients of correlation between the teeth. From the study, the following conclusions were made: 1. Mesiodistal dimension of maxillary central incisors, canines, first molars and mandibular canines, first premolars, second premolars and first molars of male are larger than that of female. 2. Korean teeth are roughly intermediate between those of American Caucasian and those of American Negro. 3. In both sexes, the relation between the first and second premolars appeared highly correlated not only in the maxillary arch but also in the mandibular arch, and the relation between the central incisor and lateral incisor appeared highly correlated in the mandibular arch. 4. The relation between the maxillary and mandibular first premolars appeared highly correlated in both sex, and the relation between the maxillary canine and mandibular canine in male as well as between the maxillary central incisor and mandibular central incisor in female appeared highly correlated.

• 대한치과의사협회지
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• 제53권6호
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• pp.402-410
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• 2015

The aims of occlusal adjustment are as follows: to eliminate occlusal interference, to redirect force generated during function to which is favorable for teeth, to improve mastication efficiency and simultaneously establish stable maximal intercuspation or centric occlusion. Also, it should permit mandible to move freely from all positions. The sequence of occlusal adjustment in natural teeth and fixed prosthesis shall be as follows: 1) Eliminate interference that prevent optimal intercuspation and recontouring adjustment 2) Establish maximal intercuspation 3) Eliminate interference in lateral mandibular movement 4) Eliminate interference in anterior mandibular movement 5) Refine occlusal relationships.

• 대한치과의사협회지
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• 제53권11호
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• pp.844-854
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• 2015

This clinical report describes an orthodontic-prosthodontic interdisciplinary treatment for a patient with multiple missing teeth and unilateral scissors bite. A 47-year-old female presented with multiple missing posterior teeth, anterior large overjet, deep bite, and posterior scissors bite on the right premolar area. Periodontal therapy was performed and followed by orthodontic treatment. The maxillary anterior teeth were initially aligned, then two implants were placed for the left mandibular molars to increase occlusal vertical dimension. The scissors bite between the right maxillary and mandibular premolars were corrected using the miniscrews as an anchorage. Other implants were placed for the right maxillary and mandibular molars after the occlusal planes and occlusal relationship were harmonized. The patient adapted well to altered vertical dimension without any specific problems including peri-implant marginal bone loss. Interdisciplinary approach resolve the complex orthodontic-prosthodontic problems and concluded in successful results.

• 치과방사선
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• 제17권1호
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• pp.163-171
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• 1987

The author has clinically and radiologically investigated 57 cases of odontogenic keratocyst in 47 patients consisted of 26 males and 21 females aged from.2 to 63 years, who were pathologically diagnosed as odontogenic keratocyst at infirmaries of dental colleges, Yonsei University and Seoul national university during 1965-1986. The results were as follows: 1. The peak incidence of the disease was on their teenagers (29.8%). The ratio of Male/Female was 1.23:1 and incidence rate of males showed higher than their counterpart. 2. The most frequent complaints were swelling in (65.9%) followed by pus discharge, unknown mass, pain, residual root. 3. The most common site was mandibular third molar and mandibular ramus region (15.8%) followed by mandibular body and ramus, mandibular third molar, mandibular anterior teeth. Incidence of this disease in mandible was higher than in maxilla. 4. The lesions not associated with adjacent teeth were (14.0%) and in the lesions associated with adjacent teeth (35.1%) showed root resorption, (50.9%) were without root resorption, (35.1%) showed tooth migration and (50.9%) were without tooth migration. 5. The border types of the lesions were scalloped type in (52.6%), smooth type in (47.4%) and morphological type were unilocular in (50.9%), multilocular in (49.1%). 6. The radiologic cyst type of the lesions were follicular type (42.1%) followed by primordial, unclassified odontogenic, residual, lateral periodontal, median mandibular, globulomaxillary type.

• 대한치과교정학회지
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• 제41권3호
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• pp.211-218
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• 2011

Objective: This case report describes orthodontic treatment of contracted mandibular arch using a trombone appliance. Methods: A 14-year-old girl with Class II division 2 malocclusion, retroclined maxillary incisors, and buccally displaced maxillary canines required dental expansion in 3 spatial directions to correct the contracted maxillary and mandibular arches. In the initial phase of treatment, the maxillary arch was expanded and distalized using a quad-helix appliance and cervical headgear. Following the expansion and leveling of the maxillary arch, a trombone appliance was used to expand the mandibular arch. On correction of the mandibular arch and provision of sufficient space to level the mandibular teeth, fixed orthodontic treatment phase was initiated. Results: A trombone appliance proved effective in correcting the contracted mandibular arch. Because of labiolingual and transversal expansion, the mandibular dental arch perimeter was increased by 7.4 mm; the misalignment of the mandibular teeth was corrected successfully. Conclusions: A trombone appliance may serve as an appropriate clinical alternative for treating moderate mandibular arch crowding caused by the contraction of the dental arch.

• The Journal of Advanced Prosthodontics
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• 제8권6호
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• pp.489-493
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• 2016

PURPOSE. This in-vitro study aimed to evaluate the fracture resistances and failure modes of endodontically treated mandibular premolars restored with endocrowns and conventional post-core retained crowns. MATERIALS AND METHODS. Thirty mandibular premolars were assigned into three groups (n=10): GI, intact teeth; GE, teeth with endocrowns; GC, teeth with conventional post-core supported crowns. Except for the teeth in group GI, all specimens were cut to 1.5 mm above the cementoenamel junction and endodontically treated. Both endocrowns and conventional crowns were fabricated from lithium-disilicate blocks using a CEREC 3D CAD/CAM unit. All specimens were subjected to thermocycling and then to $45^{\circ}$ oblique compressive load until fracture occurred. The fracture resistance and failure mode of each specimen were recorded. Data were analyzed with one-way ANOVA and LSD Post Hoc Test (${\alpha}=.05$). RESULTS. The fracture resistances of GE and GC were significantly lower than that of GI (P<.01), while no significant difference was found between GE and GC (P=.702). As of the failure mode, most of the specimens in GE and GC were unfavorable while a higher occurrence of favorable failure mode was presented in GI. CONCLUSION. For the restoration of mandibular premolar, endocrown shows no advantage in fracture resistance when compared with the conventional method. Both of the two methods cannot rehabilitate endodontically treated teeth with the same fracture resistances that intact mandibular premolars have.

• Restorative Dentistry and Endodontics
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• 제34권4호
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• pp.346-349
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• 2009

하악 제2대구치는 근관형태의 다양한 변이를 가지고 있어 근관치료시 여러가지 어려움을 야기한다. 본 연구에서는 하악 제2대구치의 여러가지 근관형태를 비율별로 분석해보고자 2005년에서 2008년까지 보라매병원에서 하악 제2대구치 근관치료를 받은 86개의 치아에서 치수강 개방 후 육안으로 근관입구의 형태를 확인하고 근관장 측정용 파일 삽입 후 방사선 사진을 촬영하여 근관형태를 기록, 분석하였다. 그 결과 C형 근관은 31.4%(27개)의 발현빈도를 보였으며 3근관 50%(43개), 4근관 12.7%(11개), 2근관 5.8%(5개)로 나타났다. C형 근관의 성별에 따른 발현빈도는 남성에서 31.7%, 여성에서 31.1%였다. 좌측 하악 제2대구치는 30.9%, 우측 하악 제2대구치는 31.8%의 C형 근관 발현빈도를 보였다.