• Journal of Periodontal and Implant Science
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• 제42권6호
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• pp.217-223
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• 2012

Purpose: Several parameters have been described for determining the success or failure of dental implants. The surface properties of transgingival implant components have had a great impact on the long-term success of dental implants. The purpose of this study was to compare the tendency of two periodontal pathogens to adhere to and colonize zirconia abutments and titanium alloys both in hard surfaces and soft tissues. Methods: Twelve patients participated in this study. Three months after implant placement, the abutments were connected. Five weeks following the abutment connections, the abutments were removed, probing depth measurements were recorded, and gingival biopsies were performed. The abutments and gingival biopsies taken from the buccal gingiva were analyzed using real-time polymerase chain reaction to compare the DNA copy numbers of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and total bacteria. The surface free energy of the abutments was calculated using the sessile water drop method before replacement. Data analyses used the Mann Whitney U-test, and P-values below 0.05 find statistical significance. Results: The present study showed no statistically significant differences between the DNA copy numbers of A. actinomycetemcomitans, P. gingivalis, and total bacteria for both the titanium and zirconia abutments and the biopsies taken from their buccal gingiva. The differences between the free surface energy of the abutments had no influence on the microbiological findings. Conclusions: Zirconia surfaces have comparable properties to titanium alloy surfaces and may be suitable and safe materials for the long-term success of dental implants.

• Journal of Oral Medicine and Pain
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• 제41권1호
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• pp.30-33
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• 2016

Malignant tumors located in the head and neck areas intermittently show symptoms similar to a temporomandibular disorder (TMD). In our case, a patient who first visited us complaining of TMD-like symptoms, such as trismus and temporomandibular joint (TMJ) pain on the left side, was identified as a sufferer of adenoid cystic carcinoma (ACC) that arose from the left maxillary sinus. The patient may have a TMD symptom, but we are skeptical because the patient also complained of a spontaneously developed numbness on the same side of his upper lip. We observed the panoramic radiograph closely and found the blurred maxillary sinus inferior wall. Dental cone-beam computed tomography confirmed the tentative diagnosis of malignancy on the maxillary sinus. After he had been referred to the Department of Otolaryngology, the diagnosis of the ACC was confirmed. Adequate diagnosis is vital for a quick treatment of the malignancy. There are some keys for differential diagnosis of TMD-like symptoms.

• Imaging Science in Dentistry
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• 제50권4호
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• pp.339-346
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• 2020

Purpose: The purpose of this study was to evaluate the image quality, diagnostic efficacy, and radiation dose associated with the use of a cadmium telluride (CdTe) detector, compared to charge-coupled device (CCD) and complementary metal oxide semiconductor(CMOS) detectors. Materials and Methods: Lateral cephalographs of a phantom (type 1) composed of synthetic polymer filled with water and another phantom (type 2) composed of human skull macerated with polymer coating were obtained with CdTe, CCD, and CMOS detectors. Dosimeters placed on the type 2 phantom were used to measure radiation. Noise levels from each image were also measured. McNamara cephalometric analysis was conducted, the dentoskeletal configurations were assessed, and a subjective evaluation of image quality was conducted. Parametric data were compared via 1-way analysis of variance with the Tukey post-hoc test, with a significance level of 5%. Subjective image quality and dentoskeletal configuration were described qualitatively. Results: A statistically significant difference was found among the images obtained with the 3 detectors(P<0.05), with the lowest noise level observed among the images obtained with the CdTe detector and a higher subjective preference demonstrated for those images. For the cephalometric analyses, no significant difference (P>0.05) was observed, and perfect agreement was seen with regard to the classifications obtained from the images acquired using the 3 detectors. The radiation dose associated with the CMOS detector was higher than the doses associated with the CCD (P<0.05) and CdTe detectors(P<0.05). Conclusion: Considering the evaluated parameters, the CdTe detector is recommended for use in clinical practice.

• Imaging Science in Dentistry
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• 제54권1호
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• pp.49-56
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• 2024

Purpose: This study evaluated the impact of artifacts generated by metal crowns on the detection of proximal caries lesions in teeth at various distances using cone-beam computed tomography (CBCT). Additionally, the diagnostic impacts of tube current and metal artifact reduction (MAR) were investigated. Materials and Methods: Thirty teeth were arranged within 10 phantoms, each containing 1 first premolar, 1 second premolar, and 1 second molar. A sound first molar (for the control group) or a tooth with a metal crown was placed. Of the 60 proximal surfaces evaluated, 15 were sound and 45 exhibited enamel caries. CBCT scans were acquired using an OP300 Maxio unit (Instrumentarium, Tuusula, Finland), while varying the tube current (4, 8, or 12.5 mA) and enabling or disabling MAR. Five observers assessed mesial and distal surfaces using a 5-point scale. Multi-way analysis of variance was employed for data comparison, with P<0.05 indicating statistical significance. Results: The area under the curve (AUC) varied from 0.40 to 0.60 (sensitivity: 0.28-0.45, specificity: 0.44-0.80). The diagnostic accuracy was not significantly affected by the presence of a metal crown, milliamperage, or MAR(P>0.05). However, the overall AUC and specificity were significantly lower for surfaces near a crown (P<0.05). Conclusion: CBCT-based caries detection was not influenced by the presence of a metal crown, variations in milliamperage, or MAR activation. However, the diagnostic accuracy was low and was further diminished for surfaces near a crown. Consequently, CBCT is not recommended for the detection of incipient caries lesions.

• Imaging Science in Dentistry
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• 제51권3호
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• pp.237-242
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• 2021

Purpose: The aim of this study was to analyse and review deep learning convolutional neural networks for detecting and diagnosing early-stage dental caries on periapical radiographs. Materials and Methods: In order to conduct this review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA) guidelines were followed. Studies published from 2015 to 2021 under the keywords(deep convolutional neural network) AND (caries), (deep learning caries) AND (convolutional neural network) AND (caries) were systematically reviewed. Results: When dental caries is improperly diagnosed, the lesion may eventually invade the enamel, dentin, and pulp tissue, leading to loss of tooth function. Rapid and precise detection and diagnosis are vital for implementing appropriate prevention and treatment of dental caries. Radiography and intraoral images are considered to play a vital role in detecting dental caries; nevertheless, studies have shown that 20% of suspicious areas are mistakenly diagnosed as dental caries using this technique; hence, diagnosis via radiography alone without an objective assessment is inaccurate. Identifying caries with a deep convolutional neural network-based detector enables the operator to distinguish changes in the location and morphological features of dental caries lesions. Deep learning algorithms have broader and more profound layers and are continually being developed, remarkably enhancing their precision in detecting and segmenting objects. Conclusion: Clinical applications of deep learning convolutional neural networks in the dental field have shown significant accuracy in detecting and diagnosing dental caries, and these models hold promise in supporting dental practitioners to improve patient outcomes.

• Journal of Korean Dental Science
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• 제9권2호
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• pp.81-89
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• 2016

Necrotizing periodontal diseases, especially acute necrotizing ulcerative gingivitis (ANUG), it should be noted, occur abruptly and progress rapidly, eventually causing severe soft-tissue and alveolar bone loss. This report presents the cases of two ANUG patients and provides a brief treatment protocol for easy and effective clinical management. After proper diagnosis, sequential treatment with cessation of mechanical brushing, along with a prescription of systemic antibiotics and chlorhexidine as a mouth rinse, scaling, root planing, and supportive periodontal therapy, was utilized. In all cases discussed in this report, there was marked improvement in a few days. ANUG, though an uncommon disease, can be efficiently managed with proper diagnosis and immediate treatment.

• 치과방사선
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• 제6권1호
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• pp.23-25
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• 1976

The patient, 19 years old male, visited with complaints of trismus and consults for construction of denture. 4 years ago, he received /sup 60/Coteletherapy of left laryngeal area for treatment of throat tumor. Clinical apperance showed rampant dental caries, multiple root rests, xerostomia, disturbance of mandibular growth and asymmetry of face. Roentgenographic examination disclosed deep cervical caries, destruction of alveolar crest, punched out bone destruction of mandible and maxilla.

• 대한치과의사협회지
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• 제25권8호통권219호
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• pp.783-788
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• 1987

The authors observed the two cases of Rieger's syndrome in 21-year-old male and 13-year-old female with a chief complaint of Partial anodontia of permanent teeth on both jaws. We had done the laboratory and ophthalmic examinations and had taken radiographs. Final diagnosis was established as Rieger's syndrome. We obtained the results as follows, 1. There was no peculiar hereditary tendency in them. 2. The patients had no disturbance of general physical activity and mentality. 3. The male patient had pseudoprogenathism, concave profile, congenital missing on upper anterior and second premolar teeth, and conical shaped crown of upper len celral incisor. The female patient had also pseudoprognathism, concave profile, thickened upper labial frenum, decreased upper dental arch width, congenital missing on upper anterior teeth, and delayed eruption of second premolars. 4. The ophthalmic symptoms that were ins abnormalities, decreased visual acuity, and increased intraocular pressure were present. 5. The abnormalities except dental and ophthalmic abnormalities were not round.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제47권1호
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• pp.51-56
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• 2021

Due to their rarity and the lack of associated dental symptoms, odontogenic cutaneous sinus tracts (OCSTs) are often misdiagnosed and confused with cutaneous lesions or non-odontogenic infections. It has been estimated that 50% of individuals affected by OCSTs are subjected to inappropriate treatments before the correct diagnosis is established. We describe the diagnosis and treatment of two cases of OCSTs. By using a computed tomography (CT) with soft tissue window setting, the extent of cortical bone destruction and the path of the sinus tract in the soft tissue was easily identified. Thus, we recommend the use of imaging techniques such as CT, which can confirm the odontogenic origin and the exact location of the OCST.

• 한국의학물리학회지:의학물리
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• 제26권1호
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• pp.52-58
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• 2015

본 연구팀이 개발한 신개념 강내형 치과 진단 장치에서 촬영한 X선 치아영상으로부터 치아 우식증을 조기 단계에서 판별하고 치과의사의 정확한 진단을 돕기 위해서 병변진단 보조시스템인 치아 와동 자동 검출 프로그램을 개발하고자 하였다. 치아 와동 자동 검출 시스템을 구성하고 있는 기본 알고리즘은 치아 와동과 정상 치아를 구분 할 수 있는 영상분별 알고리즘과 치아 영상의 고유 특성 정보를 분석하고 이를 병변 검출에 적용할 수 있는 알고리즘으로 나눌 수가 있는데, 본 연구에서는 먼저, DRLSE 방법을 적용하여 병변과 정상치아 사이의 윤곽선 분할 성능을 테스트 하였다. 개발된 알고리즘의 와식 판별 성능을 테스트하기 위해서 다양한 형태의 와식을 포함하는 전치, 견치, 소구치 등의 7개의 치아팬텀을 제작하고 치아 와식 분별을 실시하였다. 총 14 개의 와식 중에 와식의 경계를 부분적으로 식별한 2개를 제외하고는 12개 와식의 경계를 정확하게 구별하여 개발된 자동 치아 병변 알고리즘의 가능성을 입증하였다. 그러나 실제 치아 와식의 형태는 개개인마다 다르고 복잡하기 때문에 무작위로 선택된 실제 치아에 적용하기 위해서는 보강된 알고리즘이 필요하다. 향후에는 치아에 대한 사전정보를 처리하고 적용하는 패턴 인식 혹은 기계학습 알고리즘을 추가하여 보다 효과적이고 정확한 병변 알고리즘으로 개선할 예정이다.