• 한국멀티미디어학회논문지
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• 제17권10호
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• pp.1171-1181
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• 2014

In this paper, we propose improved methods which are image conversion and extraction method of watershed seed using morphological characteristic of teeth on complement image. Conventional tooth segmentation methods are occurred low detection ratio at molar region and over, overlap segmentation owing to specular reflection and morphological feature of molars. Therefore, in order to solve the problems of the conventional methods, we propose the image conversion method and improved extraction method of watershed seed. First, the image conversion method is performed using RGB, HSI space of tooth image for to extract boundary and seed of watershed efficiently. Second, watershed seed is reconstructed using morphological characteristic of teeth. Last, individual tooth segmentation is performed using proposed seed of watershed by watershed algorithm. Therefore, as a result of comparison with marker controlled watershed algorithm and the proposed method, we confirmed higher detection ratio and accuracy than marker controlled watershed algorithm.

• 대한치과의사협회지
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• 제12권9호
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• pp.707-712
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• 1974

The 800 extracted permanent teeth of first and second premolar were observed and obtained the following results: Those teeth were extracted from the population of dentistless rural area. The cause of extraction of those teeth was only the dental caries. It was performed by the free dental service team from 1966 to 1973. The findings were as follows: 1. The most incidence of caries occurrence was on the distal surface and the least was mesial side occlusal surface. 2. The average rate of decayed surface was higher in the second premolar group than the first permolar. 3. The average rate of decayed surface was higher in the teeth of mandible than maxilla. 4. The average rate of decayed surface was higher in female than male. 5. The average rate of decayed surface per tooth was 3.05±1.83.

• 대한치과의사협회지
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• 제12권3호
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• pp.177-182
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• 1974

The 800 extracted permanent teeth of first and second molar were observed and obtained the following results; Those teeth were extracted from the population of dentistless rural area. The cause of extraction of those teeth was only the dental caries. It was performed by the free dental service team from 1966 to 1972. The findings were as follows: 1. The most incidence of caries occurrence was on the occlusal surface and the least was lingual surface. 2. The distal surface caries rate was higher than the other surface except occlusals. 3. The average rate of decayed surface was higher in the second molar group than the first molar. 4. The average rate of dacayed surface was higher in the teeth of mandible than maxilla. 5. The average rate of decayed surface was higher in female than male. 6. The average rate decayed surface per tooth was 2.54±1.98.

• 대한소아치과학회지
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• 제24권4호
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• pp.788-794
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• 1997

As one of the developmental disturbance in shape of teeth, a twinning has very rare frequency in permanent teeth. Because it is possible to diagnose the twinning by use of the radiograph, it is very important to detect this anomaly early by careful examining the radiographs. The twinning produces several orthodontic problem such as crowding, protrusion, ectopic eruption of adjacent teeth. Therefore it is necessary, in proper time, the extraction and orthodontic treatment should perform.

• Journal of Dental Anesthesia and Pain Medicine
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• 제15권4호
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• pp.241-245
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• 2015

A majority of patients who sustain injuries to the peripheral sensory nerves of the face and jaws experience a slow but gradual return of sensation that is functional and tolerable, if not the same as before the injuries. However, long-term effects of such injuries are aggravating for many patients, and a few patients experience significant suffering. In some of these patients, posttraumatic symptoms become pathological and are painful. The predominant painful components are (1) numbing anesthesia dolorosa pain, (2) triggered neuralgiaform pain, (3) burning and aching causalgiaform pain, and (4) phantom pain. This is a case report of conservative management of traumatic neuralgia and neuritis as part of posttraumatic pain syndromes in geriatric patients who have undergone the teeth extraction and alveoloplasty.

• 대한심미치과학회지
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• 제31권2호
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• pp.40-46
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• 2022

상악전치부는 심미적 회복이 가장 중요한 부위이지만 구치에 비해 좁은 협설측 치조골 폭 및 발치시의 치조골 흡수로 인하여, 그만큼 심미적인 결과를 얻기가 어려운 부위이다. 본 증례 보고를 통해 외상으로 인한 상악전치부의 발치 즉시 임플란트 식립을 통해 치조골 및 연조직 소실을 최소화 하며 심미성을 확보하기 위한 고려 사항에 대해 살펴 보고자 한다.

• 한국CDE학회논문집
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• 제18권4호
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• pp.275-282
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• 2013

This paper proposes a method for human identification using teeth contours extracted from dental images that are captured from the frontal views of subjects each of who opens his or her mouth slightly. Each dental image has a black-colored region containing the subject's teeth contours which are usually different from subject to subject. This means that this black-colored region has bio-mimetic information useful for human identification. The basic idea of the method is to extract the upper and lower teeth contours from the dental image of each subject and to encode their geometric patterns using a back-propagation neural network model. After acquiring 400 teeth images form 10 university students, we used 300 images for the training data of the neural network model and 100 images for its verification. Experimental results have shown that the proposed neural network-based method can be used as an alternative solution for identification among a small group of humans with a low cost and simple setup.

• 대한소아치과학회지
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• 제10권1호
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• pp.67-76
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• 1983

The state of pulp and dental hard tissue during the process of resorption and shedding of 104 non-carious primary teeth was assessed by histomorphologic study. The teeth were extracted from the Korean school children aged 5 to 15 and classified into preshedding, shedding, delayed shedding groups according to the age of the child at the time of extraction, The results were as follows: 1. The inflammatory cell infiltration in primary pulp tissues occurred in 61.5% of observed teeth and were increased in the order of preshedding, shedding and delayed shedding stages. 2. The odontoclasts were appeared in 43.3% of observed teeth and were increased in the order of preshedding, shedding and delayed shedding stages. 3. The polymorphonuclear leukocytes and odontoclasts couldn't be observed in the exfoliated primary pulp tissues before the process of resorption has involved the root surface about 1.8mm subjacent to the cemento-enamel junction. 4. The intact root surface was the longest and largest in the preshedding stage. 5. The resorption process of primary teeth roots occurred mainly in the stage of preshedding and shedding stages. 6. There was a tendency of repair of resorbing root surfaces in the delayed shedding stage.

• Journal of Periodontal and Implant Science
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• 제36권1호
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• pp.61-68
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• 2006

The factors influencing long-term prognosis of teeth must be carefully considered. Among these, attachment level is strongly associated with tooth loss. The purpose of the present study was to estimate pattern of attachment loss based on attachment area in extracted teeth. 197 satisfied the criteria for assessment after staining. The protocol described by Waerhaug(l975) was performed. An indir ect method, based on digital image abstracted from digital camera and digital imaging software program, was used to calculate the root surface area and the attachment loss area. The data were analysed using SPSS. Except maxillary central incisior and mandibular canine, no statistical significant differences between each root surfaces were observed in anterior teeth. In posterior teeth, statistical significant differences in palatal surface of maxillary molar and mandibular molar compared with others were observed. Statistical significant difference in buccal surface compared with others was lowly observed in single and multi rooted. This study did not reveal progressive loss pattern of attachment area in each root surface but clarified root surface that has relative high loss rate of attachment area at extraction. Thus understanding this pattern of attachment loss is helpful for dentist to treat the periodontitis.

• 대한치과의사협회지
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• 제10권10호
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• pp.667-677
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• 1972