• 제목/요약/키워드: dentistry radiation

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Assessment of the Caries Detection Ability of Quantitative Light-induced Fluorescence (QLF) in Primary Teeth in vitro (유치의 치아우식증 확인을 위한 정량형광분석(QLF) 검사법의 우식탐지능력 평가)

  • Cho, Kyung Hyun;Kang, Chung-Min;Jung, Hoi-In;Lee, Tae Yang;Song, Je Seon
    • Journal of the korean academy of Pediatric Dentistry
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    • v.49 no.1
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    • pp.65-75
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    • 2022
  • The aim of this study was to evaluate QLF (quantitative light-induced fluorescence) technology for the caries detection in primary teeth and validate the relationships between the cavity volume of carious lesions and QLF analysis results. Total 125 tooth surfaces include 53 occlusal surfaces, and 72 proximal surfaces were investigated with the portable QLF device for detection of dental caries in primary molars. Micro-CT radiograph was also performed to classify carious lesions and calculate the cavity volume. QLF showed good accuracy and reliability (sensitivity 0.75 - 0.94, specificity 0.82 - 0.95, and AUROC 0.88 - 0.98) for the caries detection in primary teeth except 𝚫R average results of proximal caries which showed relatively low values. Statistically significant relationships were found between 𝚫F average, QS-Index and the cavity volume according to Spearman rank-order correlation coefficients (r = 0.805 - 0.832, p < 0.001). QLF detection method would be a harmless and reliable way for children to diagnose dental caries without the concern about radiation exposure.

Changes in Oral Microbiota in Patients Receiving Radical Concurrent Chemoradiotherapy for The Head and Neck Squamous Cell Carcinoma

  • Kim, Jin Ho;Choi, Yoon Hee;An, Soo-Youn;Son, Hee Young;Choi, Chulwon;Kim, Seyeon;Chung, Jin;Na, Hee Sam
    • International Journal of Oral Biology
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    • v.43 no.1
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    • pp.13-21
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    • 2018
  • Radiotherapy (RT) is a mainstay in the treatment of head and neck squamous cell carcinoma (HNSCC). For locally advanced HCSCC, concurrent chemoradiotherapy (CCRT) benefits HCSCC patients in terms of better survival and loco-regional control. In this study, we evaluated changes in oral microbiota in patients, who received CCRT for head and neck cancer. Oral rinsed samples were weekly collected before and during CCRT and at 4 weeks following treatment from HNSCC patients, who had received 70 Gy of radiation delivered to the primary sites for over 7 weeks and concurrent chemotherapy. Oral microbiota changes in three patients were analyzed by next-generation sequencing using 16S rRNA 454 pyrosequencing. On an average, 15,000 partial 16S rRNA gene sequences were obtained from each sample. All sequences fell into 11 different bacterial phyla. During early CCRT, the microbial diversity gradually decreased. In a patient, who did not receive any antibiotics during the CCRT, Firmicutes and Proteobacteria were the most abundant phylum. During the early CCRT, proteobacteria gradually decreased while Firmicutes increased. During the late CCRT, firmicutes gradually decreased while Bacteroides and Fusobacteria increased. In all the patients, yellow complex showed a gradual decrease, while orange and red complex showed a gradual increase during the CCRT. At 4 weeks after CCRT, the recovery of oral microbiota diversity was limited. During CCRT, there was a gradual increase in major periodontopathogens in association with the deterioration of the oral hygiene. Henceforth, it is proposed that understanding oral microbiota shift should provide better information for the development of effective oral care programs for patients receiving CCRT for HNSCC.

EXPERIMENTAL STUDY ON THE EFFECT OF RADIATION IN THE SECONDARY PALATE FORMATION. (방사선조사가 구강형성기에 미치는 영향에 관한 실험적 연구)

  • You Dong Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.7 no.1
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    • pp.9-15
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    • 1977
  • The author observed the effect of X-ray irradiation on the secondary palate formation of the rat fetuses. The mothers were exposed to X-radiation on the 10½th, 11½th and 12½th day of gestation with respectively 150, 200, 250, 300 and 350 rads. The fetuses were removed from mothers on 15½h, 16½th and 18½th day of gestation. Morphological changes in palate formation were examined and histochemical preparations were made. 1. In control fetuses, the secondary palates were fully developed on the 15½th to 18½th day of gestation. But in experimental fetuses, many cleft palates were observed in accordance with increase of X-radiation dose. 2. Frequency of incidence of horizontal position of both palated shelves in cleft palate was highest. 3. Accordig to the dislocation of palatal processes, the stain ability of palatal crest was varied. 4. The thickened area of palatal epithelium of palatal crest showed intense methyl green-pyronin and PAS reaction 5. Mesenchymal cell condensation was appeared under the thickened epithelium of palatal process and this mesenchymal tissue showed strong colloidal iron reaction. 6. The stain ability of alizarin red S and alkaline phosphatase reaction of tectal ridge were decreased, in accordance with increase of irradiation doses.

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CLINICAL STUDIES OF MALIGNANT TUMORS IN THE ORAL AND MAXILLOFACIAL REGION (구강 악안면 부위의 악성종양에 관한 임상적 연구)

  • Suh, Ki-Hang;Kim, Oh-Whan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.12 no.1
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    • pp.82-95
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    • 1990
  • A clinico-statistical study was made of 237 case, 186 male and 51 female of oral and maxillofacial malignant cancer patients at Presbyterian Medical Center in Chon-ju between 1984 January and 1988 December. In 204 cases of the carcinoma, 154 cases were pathologically diagnosed as squamous cell carcinoma. More than 65% of the cases were clinically adbanced cases (stage III or IV), and 154 cases of 237 cases were treated. Most cases were treated by surgery (S)+radiation (R)+chemotherapy (C) or S+R or R+C. The expired cases were 20 cases. 11 cases of them were found in stage III.

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Pathophysiology of Oral Mucositis induced by Anticancer Therapy (항암치료 후 발생하는 구강 점막염의 병태생리)

  • Yoon, Jung-Hoon;Choj, Jong-Hoon
    • Journal of Oral Medicine and Pain
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    • v.25 no.4
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    • pp.365-369
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    • 2000
  • Oral mucositis or stomatitis produced by stomatotoxic chemotherapy and/or radiation therapy are painful, restrict oral intake and, importantly, act as sites of secondary infection and potals of entry for the endogenous oral microflora often leading to bacteremias or sepsis. A number of clinical observations and studies of animal model suggests a pathophysiological complexity in the development of mucositis. The condition appears to represent a sequential interaction of the oral mucosal cells and tissues, pro-inflammatory cytokines, and local environmental factors in the mouth. This article discussed and reviewed biological process of the mucositis and, the role of cytokines as initiators and amplifiers of the process. The recognition that the pathophysiology of mucositis is a multifactorial process has presented opportunities for intervention based upon biological attenuation.

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VERRUCOUS CARCINOMA A CASE REPORT (우췌성암종;증례보고)

  • Jang, Hyun-Seon;Kim, Su-Gwan
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.23 no.3
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    • pp.277-280
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    • 2001
  • Verrucous carcinoma is a distinctive, extremely well-differentiated, slow-growing variant of the squamous cell carcinoma. Verrucous carcinoma of the oral cavity is relatively rare. McCoy reported about 49 verrucous carcinomas of the oral cavity. McCoy reported that the most common site of occurrence was the buccal mucosa, followed by the mandibular alveolar ridge and gingiva, and that The majority of the patients were between the ages of 50 and 80 years. Although most other series of oral verrucous carcinoma show a male predominence, our case occurred in female. The role of radiation therapy in treatment of oral verrucous carcinoma is controversial, and adequate surgical excision appears to be the treatment of choice. In this paper a case of verrucous carcinoma of the buccal mucosa and a review of the literature is presented.

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AN EXPERIMENTAL STUDY ON THE CHANGE OF BONE MINERAL METABOLISM AFTER IRRADIATION (방사선조사가 골무기질함량에 미치는 영양에 관한 실험적 연구)

  • Chin Hae Yun;Lee Sang Rae
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.18 no.1
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    • pp.53-66
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    • 1988
  • Irradiation is widely used for the treatment of malignant diseases, and possibly cause the osteoporosis. The bone densitometry and bone scintigraphy are valuable when used to monitor the patients longitudinally to access the progression of osteoporosis and risk of osteoradionecrosis. To evaluate the osteoporosis after irradiation of cobalt-60 gamma ray on the lumbar spines of New Zealand white rabbits, bone densitometry by dual photon absortiometry and bone scintigraphy were performed weekly. The decrease of bone density began at the first week after irradiation, and were in the nadir at 4-6th week. The osteoblastic activity measured by bone scintigraphy decreased in the first week, and was in the nadir at 4-6th week. The severity of these changes were related to the radiation dose. In conclusion, the osteoporosis before presentation of the osteoradionecrosis can be developed at low dose irradiation and confirmed by bone densitometry, bone scanning, and histopathology.

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Assessment of panoramic radiography as a national oral examination tool: review of the literature

  • Choi, Jin-Woo
    • Imaging Science in Dentistry
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    • v.41 no.1
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    • pp.1-6
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    • 2011
  • Purpose : The purpose of this review is to evaluate the possibility of panoramic radiography as a national oral examination tool. Materials and Methods : This report was carried out by review of the literatures. Results : Panoramic radiography has sufficient diagnostic accuracy in dental caries, periodontal diseases, and other lesions. Also, the effective dose of panoramic radiography is lower than traditional full-mouth periapical radiography. Conclusion : Panoramic radiography will improve the efficacy of dental examination in national oral examination. However, more studies are required to evaluate the benefit, financial cost, and operation time and also to make selection criteria and quality management program.

Corrosion Behaviors of Ti-xNb Alloys for Biomaterials

  • Byeon, In-Seop;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.186-186
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    • 2014
  • In this study, corrosion behaviors of Ti-xNb alloys for biomaterials. The Ti-xNb binary alloys contained from 10 wt. % to 50 wt. % contents were manufactured by vacuum arc-melting furnace. Microstructures of the alloys were examined by optical microscope (OM) and field emission scanning electron microscope (FE-SEM). In order to identify the phase constitutents of the Ti-xNb alloys, X-ray diffractometer (XRD) with a Cu K radiation was used. The corrosion behaviors were investigated using potentiostat (Model2273,EG & GCo, USA) in NaCl solution at $(36.6{\pm}1.0)^{\circ}C$.

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RADIOGRAPHIC STUDY OF MORPHOLOGY OF MANDIBULAR CONDYLE (하악두 형태의 X선학적 연구)

  • Ahn Hyung Kyu
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.15 no.1
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    • pp.7-12
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    • 1985
  • Anatomical anomaly of temporo-madiblar joint and its dysfunction is becoming one of the important problem in dentistry because the number of these cases are increasing rapidly. Applying 'Lateral Transcranial Technic', 'Updegrave method' and 'Denar Accuard 100' to skull and adult with normal occlusion the author obtained following results: 1. Grewcock method combied with cephalostat as one of 'Lateral Transcranial Technic' revealed clear picture but the image of condyle head was tend to incline downward. 2. Direction of central radiation in 'Updegrave method' should be 2 recommended inch upward from auditorial mearus. 3. For functional analysis and correct diagnosis 'Denar Accuard 100' should be highly recommended.

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