• 대한소아치과학회지
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• 제32권3호
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• pp.531-536
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• 2005

저위교합이란 능동적 맹출기 동안이나 이후 해당치아의 교합면 방향으로의 성장이 멈추어 다른 치아들보다 하방에 존재하는 것을 말한다 저위교합치의 결과로 침하치의 만기잔존, 부정교합, 증가된 치아우식 감수성과 치주질환의 가능성, 계승치의 이동 등이 나타날 수 있다. 따라서 조기진단 및 적절한 처치가 필요하다. 저위교합치의 치료는 저위교합 정도나 후속 영구치의 발육정도에 따라 보존에서 발치까지 다양하다. 영구 계승치가 없거나 부분적인 침하치가 치주적으로 건전한 경우, 공간문제를 발생하지 않는 경우 보존적인 접근이 추천되기도 한다. 그러나 계승치가 존재하고 맹출이 지연되는 경우, 국소적인 염증반응과 관련되는 경우, 교정적인 치료가 필요한 경우에는 발거가 필요할 수도 있다. 특히 저위교합된 유구치의 상방으로 인접치가 경사되어 악궁장경에 문제를 초래할 위험이 있는 경우 외과적인 발치가 필요할 수도 있으며 경사가 심한 경우 발치를 위한 외과적 접근이 힘들 수 있다. 심하게 경사된 인접치로 인하여 저위교합치의 외과적 발거가 힘든 환아에서 가철성 교정장치를 이용하여 공간확보를 선행하였으며 보다 용이하게 치아를 발거할 수 있었다.

• Restorative Dentistry and Endodontics
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• 제13권2호
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• pp.337-348
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• 1988

The purpose of this study was to examine the fracture strength and characteristics of teeth with MOD cavity preparation. Freshly extracted sound maxillary premolars were cleaned and stored in normal saline solution $37^{\circ}C$ for 72 hours before experiments. The roots of teeth were embedded in a self-curing resin, and the exposed crown were maintained in a vertical position by a modelling wax in a brass ring. The MOD cavities were prepared with No. 57 carbide bur under high speed to a depth of 2.0mm and a width of 2.0mm(Fig.1). All the prepared teeth specimens were divided into 7 groups according to the mode of cavity form and restorative materials (Table 1, 2): Group I, unpreapred, intact teeth as control Group II, prepared cavity without restoration Group III, prepared teeth restored with amalgam Group IV, prepared teeth restored with composite resin (P-10) Group V, prepared teeth with beveled enamel margins restored with composite resin (P-10) Group VI, prepared teeth restored with light-cured composite resin (P-30) Group VII, prepard teeth with beveled enamel margins restored with light-cured composite resin (P-30) After placement of restorations, all of the specimens were stored in water at $37^{\circ}C$ for 72 hours before testing. All of the specimens were tested on the Instron Universal Testing machine (No. 6025) in order to evaluate the strength of fracture. One metal ball 5.0mm in diameter contacting the specimens parallel to the occlusal surface was used to in this study (Fig. 1). The fracture characteristics of the specimens were examined with naked eye and in the scanning electron microscope (JSM-20). The results obtained from this study were as follows: 1. The mean fracture strength was the highest in group VI and that in group II was the lowest. 2. The progress of crack of teeth propagated into the pulp cavity. 3. In case of the group of the restored teeth, the crack occurred to be accompanied with cuspal fracture. 4. The crack of restored teeth was initiated along the pulpo-axial line angle of the cavity.

• 대한치과보철학회지
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• 제11권1호
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• pp.15-21
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• 1971

The prime objective of this study was to analyze the positional relationship of the lips to the anterior teeth according to age, sex, and both sides of the dental arch in 381 healthy Korean adults with normal occlusion ranging from 17 to 70 years over old. The results were as follows; 1. In the position of the corner of the mouth to the teeth, the range from center of canine to mesial side of first premolar was revealed the incidence of 81~87%, the distal side of canine was the hiqhest frequency of 39~43%. 2. A straight type (76~79%) of lip line was prevailed against the curved type in rest position. 3. In the exposed type of anterior teeth to upper lip in rest position, type III(50~52%) Grade 2 (26~29%) was revealed the highest frequency of occurences. 4. No significant difference in both sexes and sides of the dental arch was observed. 5. Lip position to the teeth with aging was showed the tendency toward straight type in lip line and toward reduction of the number of exposed type of upper anterior teeth to upper lip, and the corner of the mouth was placed posteriorly.

• 대한치과보철학회지
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• 제26권1호
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• pp.185-196
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• 1988

The purpose of this investigation was to analyze the color of natural teeth by means of the OFC-1001 DP colorimeter which could measure in Adams Coordinate System (L,a,b system). The subjects were the 164 persons (82 men and 82 women) ranged from the teen to the sixtieth who had come to infirmary of dental college, Chosun University. The colors of incisal third, middle third and cervical third of maxillary right incisor, maxillary right canine and maxillary right second premolar were examined after the teeth were cleaned, polished and dried. The data were analyzed statistically by means of SPSS (Statistical Package For the Social Science). The results were as follows. 1. The means of L(lightness), a (red chromaticity), b (yellow chromaticity) of all teeth were measured (Table 2,3,4). 2. The color of teeth was yellowish-gray or bluish-gray. 3. The L value and b value of the cervical third was greater than those of the incisal and middle third. 4. The L value of maxillary 2nd premolar was greater than those of maxillary incisor md maxillay canine. 5. The a & b values of maxillary canine were greater than those of maxillary incisor and maxillary 2nd premolar. 6. The average values of L,a,b of teeth between male and female were not significant. 7. The L values of teeth were decreasing and the b values of teeth were increasing as the age was increased, but there was no corelation between the a values and aging.

• 한국CDE학회논문집
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• 제20권4호
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• pp.348-356
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• 2015

It is important to devise methods for assisting dentists to consistently determine implant positions and directions and to accurately perform drilling tasks during dental implant surgery. In this paper, we propose a novel approach to tooth implant placement planning which deals with the determination of the positions and directions of multiple implant fixtures for a set of missing mandibular teeth and suggests the selection of the sizes and types of the implant fixtures. We combine Korean standard data in the sizes and positions of human teeth with the patient specific 3D models of mandibular jawbones, nerve curves, and neighboring teeth around the missing teeth in order to determine the positions and directions of the implant fixtures for the missing teeth. Using the geometric and spatial information of the jawbones, the teeth and the implant fixtures, we can construct the 3D models of surgical guide stents which are crucial to perform drilling tasks with ease and accuracy. Adopted in 3D simulation of dental implant placement, the approach can provide surgeon students with good educational contents. We also expect that, with further work, the approach can be used as a useful tool to plan for dental implant surgery.

• 대한치과보철학회지
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• 제34권3호
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• pp.457-463
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• 1996

An esthetically pleasing result in denture service is dependent upon several consideration. Esthetic considerations for the edentulous patient include tooth size, shape, arrangement, positioning, gingival contour, age, sex, personality differences, and ethnic type. Especially, the form of anterior artificial teeth is an important factor on the esthetics. The selection of artificaial teeth requires understanding and knowledge on physical and biologic factors and has to meet the indivisul esthetics and functional needs of each patient. However, the selection of artificial teeth is based on the large degree of subjective judgement of the dentist, Therefore, this is one of the most unscientific processes. Many attempts have been made to find a guideline for the selection of artificial teeth. Temperamental theory by White and Hall utillized with the physical characteristics such as body size, body form, color of eyes and hair, and disposition. SPA theory by Frush and Fisher utilized with the basis of sex, personalities, and age of the indivisual. There has not been provided for a guideline and study on the selection of artificial teeth for Koreans yet. This study was aimed to evaluate the William's typal matching theory in Koreans. 1. The facial forms of korean adult were ovoid(46.3%), square(36.7%) and tapered(17.0%) form. 2. The anatomic forms of natural maxillary incisors were ovoid(45.3%), tapered(31.3%), square(23.3%) form. 3. The forms of face and natural maxillary incisors were ovoid(21.9%), squared(11%), tapered(6.3%). 4. The natural maxillary incisors were similar in form to the facial form only in 39%. There was no correlation between the form of the face and the form of natural maxillary central inisors in Koreans. 5. Artificaial teeth which was selected according to the typal matching theory did not represent the form of the natural teeth in 61 per cents of the fatal, but it felt that they harmonized with the form of the patient's face and produced good results.

• 구강회복응용과학지
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• 제32권1호
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• pp.80-86
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• 2016

잔존 지대치의 수가 적은 경우 이중관 가철성 국소의치를 사용한 여러 보고에서 우수한 결과가 나타남을 확인할 수 있다. 특히 치주 상태가 양호하지 않고 고립된 소수 잔존치를 지대치로 이용하여 국소의치로 수복해야 하는 경우에 프릭션핀을 이용한 하이브리드 텔레스코픽 이중관은 적절한 적응증이 될 수 있다. 본 증례는 심한 치주염으로 다수 치아 발치 후 상악은 전치부 고정성 보철 수복과 Kennedy class I 가철성 국소의치로 수복하고 하악은 양측성 고립 지대치만 남아있어 클래스프 국소의치로 수복하기에 예후가 불분명하여 프릭션핀을 이용한 하이브리드 텔레스코픽 이중관 국소의치를 이용하였다. 이중관 가철성 국소의치의 특성과 효용성을 고찰해 보고자 본 증례를 보고한다.

• Imaging Science in Dentistry
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• 제47권2호
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• pp.109-115
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• 2017

Purpose: The aim of this study was to assess the ex vivo diagnostic ability of 9 different cone-beam computed tomography (CBCT) settings in the detection of recurrent caries under amalgam restorations in primary teeth. Materials and Methods: Fifty-two primary teeth were used. Twenty-six teeth had dentine caries and 26 teeth did not have dentine caries. Black class II cavities were prepared and restored with amalgam. In the 26 carious teeth, recurrent caries were left under restorations. The other 26 intact teeth that did not have caries served as controls. Teeth were imaged using a $100{\times}90-mm$ field of view and a 0.2-mm voxel size with 9 different CBCT settings. Four observers assessed the images using a 5-point scale. Kappa values were calculated to assess observer agreement. CBCT settings were compared with the gold standard using a receiver operating characteristic analysis. The area under the curve (AUC) values for each setting were compared using the chi-square test, with a significance level of ${\alpha}=.05$. Results: Intraobserver kappa values ranged from 0.366 to 0.664 for observer 1, from 0.311 to 0.447 for observer 2, from 0.597 to 1.000 for observer 3, and from 0.869 to 1 for observer 4. Furthermore, interobserver kappa values among the observers ranged from 0.133 to 0.814 for the first reading and from 0.197 to 0.805 for the second reading. The highest AUC values were found for setting 5 (0.5916) and setting 3 (0.5886), and were not found to be statistically significant(P>.05). Conclusion: Variations in tube voltage and tube current did not affect the detection of recurrent caries under amalgam restorations in primary teeth.

• Imaging Science in Dentistry
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• 제46권4호
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• pp.251-258
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• 2016

Purpose: The aim of this study was to examine the radiographic features associated with impacted premaxillary supernumerary teeth, to determine the relationship between their characteristics and their effects on permanent incisors, and to investigate the types of orthodontic treatment that patients received after the extraction of impacted supernumerary teeth. Materials and Methods: The clinical records and radiographs of 193 patients whose impacted premaxillary supernumerary teeth were removed were retrospectively reviewed, and 241 impacted supernumerary teeth were examined. Cone-beam computed tomographic images and panoramic radiographs were examined to determine the number, location, sagittal position, orientation, and morphology of the supernumerary teeth. Their effects on permanent incisors and the orthodontic treatment received by patients after the extraction of the supernumeraries were also investigated. Results: Supernumerary teeth were most frequently observed in the central incisor region, in the palatal position, in the inverted orientation, and were most commonly conical in shape. The most common complication was median diastema, followed by displacement and delayed eruption of the adjacent incisors. Ten (71.4%) of the 14 odontomas showed delayed eruption of the adjacent incisors. Displacement of the incisors was more frequently observed in association with supernumerary teeth with tuberculate or supplemental shapes. Orthodontic traction was most frequently performed after the removal of odontomas. In 32 cases (13.3%), permanent incisors erupted after the orthodontic creation of sufficient space. Conclusion: Median diastema was most common complication. The delayed eruption of incisors was common in supernumerary teeth with a vertical orientation and an odontoma shape.

• 치위생과학회지
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• 제17권5호
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• pp.447-453
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• 2017

The purpose of this study was to analyze the relationship between objective oral health status determined by dentists, self-perceived subjective oral health status, and oral health related quality of life (OHRQoL) in the elderly. The related factors affecting OHRQoL in the elderly were also surveyed. Four hundred and thirty elderly individuals who visited the three public health centers and four dental clinics in Busan were selected by convenience sampling. Twelve dental hygienists investigated the subjective oral health status and OHRQoL using the 14-item Oral Health Impact Profile (OHIP-14) and twentyone dentists examined the objective oral health status, including healthy remaining teeth, treated remaining teeth, functional remaining teeth, missing teeth, and non-treated missing teeth. Data were analyzed using SPSS ver. 12.0. OHRQoL was higher when oral and periodontal status was perceived as healthy, when there was no toothache, no interference in mastication, and when study subjects had the ability of food softening. It was also higher when study subjects had ${\geq}20$ remaining teeth and <9 missing teeth, and were wearing denture. The related factors affecting OHRQoL of the elderly were the type of medical insurance, toothache, ability of food softening, perception of periodontal status, and the number of healthy remaining teeth. There was a significant relationship between the subjective-objective oral health status and OHRQoL in the elderly. A continuous oral health care system aimed at retaining ${\geq}20$ healthy remaining teeth is needed to improve oral health and OHRQoL for the elderly, especially for the elderly receiving medical aid.