• Imaging Science in Dentistry
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• 제30권1호
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• pp.49-54
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• 2000

Purpose : To compare the diagnostic performance of clinical and radiologic examination for the interproximal caries on intraoral periapical radiographs and to evaluate the value of periapical radiographs. Methods: One hundred seven dental patients were examined clinically, with a mouth mirror and an explorer, by a dentist at the department of oral medicine, and the presence or absence of interproximal caries lesion was recorded. The patients were prescribed one or more dental periapical radiographs. Radiographs were assessed for the presence of interproximal caries by three oral and maxillofacial radiologists independantly. Two thousand sixty interproximal surfaces were included in this study. The diagnostic accuracies of clinical and radiologic examinations for interproximal caries were calculated. To assess the degree of agreement between clinical and radiologic examinations, Cohen's coefficient of agreement was computed. Results: The specificity of clinical and radiologic examination was 0.991, 0.997 and the sensitivity was 0.279, 0.985 respectively. The diagnostic accuracy of radiologic examination was statistically significantly higher than that of clinical examination (P<0.05). Cohen's kappa value of clinical and radiologic examination was 0.335, 0.942 respectively. These results suggested that clinical examination show only fair agreement, whereas radiologic examination show perfect agreement. Conclusion: The diagnositic performance of the dental periapical radiographs on interproximal caries were higher than that of clinical examination, thus this study showed the validity of periapical radiographs for detecting interproximal caries lesion without bitewing radiograph.

• 치과방사선
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• 제29권1호
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• pp.241-254
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• 1999

The purpose of this study was to investigate whether a radiometric analysis of radicular cysts and periapical granulomas is useful in the differential diagnosis. In this experiment, twenty-nine periapical radiographs of the radicular cyst and those periapical granuloma were used. The periapical radiography was taken by intraoral paralleling device. The X-ray film was digitized and digitally filtered to reduce film-grain noise. We estimated density difference of the inner/outer area, roundness or circularity, bone profile or scan line of the margin and cumulative percentage frequency curve of radicular cyst & periapical granuloma. The obtained results were as follows; 1. The differences in density between ROIs of inner and outer area of radicular cysts were smaller than those of periapical granulomas. 2. The equivalent circular diameter was over 6.3mm, there was significant difference between periapical cyst and periapical granuloma. 3. In differential diagnosis of radicular cyst and periapical granuloma using bone profile. sensitivity. specificity and accuracy were considerably high(0.83. 0.86. 0.86) respectively. 4. Cumulative percentage frequency curve of the radicular cyst was closer to the pseudo-pixel value of 50 than average curve, whereas periapical granuloma was closer to that of 0. Hence we conclude that digital radiometric features might be useful in the differential diagnosis between radicular cyst and periapical granuloma.

• Imaging Science in Dentistry
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• 제51권4호
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• pp.455-460
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• 2021

This report presents a rare case of maxillary osteoblastoma in a 17-year-old female. The patient presented with dull pain and facial asymmetry inferior to the left zygoma. An intraoral examination found a painless swelling on the buccal gingival tissue in the left posterior maxilla. Panoramic radiographs and multidetector computed tomographic images revealed an ill-defined, non-corticated, mixed attenuating entity of osseous density located within the left posterior maxilla apical to the left maxillary molars. The entity exhibited a heterogeneous internal structure with a fine granular appearance, and the periphery showed a partial hypo-attenuating rim along the antero-medial aspect. Expansion of the left posterior maxilla accompanied with displacement of the left maxillary sinus floor was noted. External root resorption of the first and second molars was noted, as well as postero-superior displacement of the third molar. The histopathologic diagnosis of the biopsy was osteoblastoma. Complete excision of the tumor was performed.

• Imaging Science in Dentistry
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• 제54권2호
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• pp.211-220
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• 2024

Non-secretory multiple myeloma (NSMM) is a rare cancer of plasma cells characterized by the absence of detectable monoclonal M protein in the blood or urine. A 57-year-old woman presented with mandibular pain but without intraoral swelling. Imaging studies revealed multiple osteolytic lesions in her mandible and pronounced root resorption of the left mandibular second molar. Biopsy results showed atypical plasmacytoid cells positive for anti-kappa, CD138, MUM1, and CD79a antibodies, but negative for anti-lambda and CD20. These results were indicative of a malignant plasma cell neoplasm. No abnormalities were revealed by free light chain assay or by serum or urine protein electrophoresis, leading to a diagnosis of NSMM. The patient began chemotherapy in conjunction with bisphosphonate therapy and achieved remission following treatment. This case underscores the critical role of dentists in the early detection and prevention of NSMM complications, as the disease can initially present in the oral cavity.

• 구강회복응용과학지
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• 제29권4호
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• pp.377-383
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• 2013

이 연구의 목적은 치과임상에서 사용되는 8종의 합착용 시멘트의 방사선불투과성을 디지털 방사선 촬영술로 평가하는 것이었다. BisCem, Clearfil SA Luting, Duolink, Maxcem Elite, Multilink Speed, Panavia F 2.0, RelyX Unicem Clicker, V-link의 8종의 재료를 5개의 원형 시편 (직경: 4 mm, 두께: 1 mm)으로 제작하였고 사람 치아의 법랑질과 상아질 시편을 1 mm 두께로 준비하여 알루미늄 스텝 웨지와 함께 촬영하였다. 관전압 70kVP, 관전류 4 mA, 노출시간 0.156초, 초첨 필름간 거리는 30 cm으로 영상판을 이용하여 촬영하였으며, ImageJ 소프트웨어를 이용하여 평균 회색조 수치를 측정하고, 이를 흡수계수로 환산한 후 검량선(calibration curve)을 이용하여 각 합착용 시멘트의 등가 알루미늄 두께를 구하였다. 합착용 시멘트의 평균 방사선불투과성은 알루미늄 두께 0.71 ~ 5.66 mm로, RelyX Unicem Clicker (0.71 mm Al)을 제외하고는 등가 알루미늄 두께 보다 높은 방사선불투과성을 보여 ISO 규격을 만족하였으며, 법랑질은 1.79 mm, 상아질은 0.19 mm 두께의 알루미늄에 해당하는 방사선불투과성을 나타내었다.

• 대한치과교정학회지
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• 제20권3호
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• pp.447-462
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• 1990

The objective of this experiment is to observe structural differences in the othodontic movement of vital (control group) and devitalized (experimental group) teeth in the mongrel dogs. The 5 utilized dogs in this experiment were approximately 1 year of age and their average weight was about 12 Kg. Endodontic therapy was performed on the 2nd premolars in upper & lower jaws of each animal under the general anesthesia by intravascular injection of 25mg/kg of pentobarbital sodium. The canals of the teeth were obturated by using gutta percha in conjunction with root canal sealer (AH26 Densply). One of the roots in the 2nd premolars was hemisected to make an extraction space for the devitalized teeth to be moved. The edgewise technique was employed for the movement of the teeth. Orthodontic models and intraoral roentgenograms were taken before and after orthodontic tooth movement. The open coil springs (.010 x .040) were used at interbraket space in order to provide equal forces (75gm) between the teeth in each arch wire. After 13 weeks of active orthodontic tooth movement, dogs were sacrified and the experimental results w ere examined through the intraoral radiography, microscopic examination and scanning electromicroscopic examination at the root sulfate. From the results of the study, the following conclusions may be drawn: The root resolution and cemental deposition were observed within the pressure and tension site in both group. 2. The root resorbed lacunae were observed in the cementum and/or into the dentin in both group. 3. The prominent osteoblastic activities were observed on the alveolar margin in the tension site in both group. 4. A few of blood vessels were observed in the pressure site, but also lots of blood vessels were observed in the tension site especially in the periphery of the alveolar bone in both group. 5. In the pressure site, resorbed lacunae were formed with deep and narrow cavity in the control group; the shallow and wide cavity in the experimental group. 6. In the pressure site, the repaired cementum or cementoid tissue was lined on cementum in the experimental group, but not in the control group. 7. There was no significant difference between external root resolution of endodontically and vital teeth when both were subjected to orthodontic forces.

• 대한방사선기술학회지:방사선기술과학
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• 제33권2호
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• pp.109-120
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• 2010

치과 X선 검사 시 환자선량의 권고량 가이드라인을 개발하기 위해서 우선 국내 치과방사 선의 현황 및 이용 실태를 설문조사하여 비교분석하였다. 응답을 받은 77곳의 치과병 의원 중에서 치과대학이 있는 치과대학병원을 A그룹(11곳), 치과대학이 없는 대학병원을 포함한 치과병원을 B그룹(30곳), 치과의원을 C그룹(36곳)으로 분류하였다. 그룹별로 분석한 결과는 다음과 같았다. 치과병 의원 한 곳당 평균 unit chairs수는 A그룹 140.2개, B그룹 15.3개, C그룹 5.8개, 평균치과의사수는 A그룹 112.6명, B그룹 7.3명, C그룹 1.7명, 평균방사선사수는 A그룹 3.1명, B그룹 0.5명, C그룹에는 한 명도 없었고, 평균치과위생사수는 A그룹 19.7명, B그룹 12.5명, C그룹 3.3명이었다. 설치된 치과용 X선장치의 평균보유수는 A그룹 14.64대, B그룹 3.21대, C그룹 2.19대로 나타났다. 이 중에서 구내촬영장치가 가장 많았고, 다음은 파노라마 장치, 세팔로 장치, CBCT 장치 순이었으며, 장치시스템의 비율은 세 그룹 모두 DR 시스템이 50% 이상으로 가장 많았다. 필름 시스템인 경우, 사용된 구내필름은 감광도가 높은 Insight 필름(Kodak, USA)이 대부분이었으며, 자동 현상기는 사용하는 곳이 적었으나, 필름유지기구는 사용하는 곳이 약간 많았다. PACS 이용률은 A그룹 90.9%, B그룹 83.3%, C그룹 16.7%이었고, 프로그램은 국내의 Infinitt에서 개발된 PiView STAR가 가장 많이 이용되고 있었다. 치과병 의원 한 곳당 2008년도의 연간 평균촬영건수는 A그룹이 B그룹보다 6.8배, C그룹보다 21.2배 더 많았으며, 구내 치근단 촬영과 파노라마 촬영이 대부분이었다. 구내 치근단 촬영 시 관전압과 관전류는 세 그룹 모두 비슷하였으나, 노출시간은 C그룹이 A그룹의 12배, B 그룹의 3.5배 정도 길었다. 즉, 대부분 치과위생사가 촬영하고 있는 C그룹에서는 방사선 노출량이 다른 그룹에 비해 훨씬 많았다. 그러나 파노라마촬영 시의 조건은 세 그룹에서 큰 차이가 없었다. 결론적으로, 촬영조건은 경험적 지식을 따르기보다는 권장량을 사용해야 하며, 필름시스템에서는 자동현상기와 필름유지기구를 사용하여 방사선의 노출량을 줄여준다. 또한 환자선량의 감소와 X선 영상의 질 향상을위해서 X선발생장치 및 관련기기의 체계적인 정도관리가 반드시 필요하다.

• 치과방사선
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• 제29권2호
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• pp.423-433
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• 1999

Purpose : To assess the methods for the clinical evaluation of the longitudinal bone changes after implantation of tooth ash-plaster mixture into the defect area of human jaws. Materials and methods : Tooth ash-plaster mixtures were implanted into the defects of 8 human jaws. 48 intraoral radiograms taken with copper step wedge as reference at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture were used. X-ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite block. The images inputted by Quick scanner were digitized and analyzed by NIH image program. Cu­equivalent values were measured at the implanted sites from the periodic digital images. Analysis was performed by the bidirectional subtraction with color enhancement and the surface plot of resliced contiguous image. The obtained results by the two methods were compared with Cu­equivalent value changes. Results : The average determination coefficient of Cu-equivalent equations was 0.9988 and the coefficient of variation of measured Cu values ranged from 0.08~0.10. The coefficient of variation of Cu-equivalent values measured at the areas of the mixture and the bone by the conversion equation ranged from 0.06 ~0.09. The analyzed results by the bidirectional subtraction with color enhancement were coincident with the changes of Cu-equivalent values. The surface plot of the resliced contiguous image showed the three dimensional view of the longitudinal bone changes on one image and also coincident with Cu-equivalent value changes after implantation. Conclusion : The bidirectional subtraction with color enhancement and the surface plot of the resliced contiguous image was very effective and reasonable to analyze clinically and qualitatively the longitudinal bone change. These methods are expected to be applicable to the non-destructive test in other fields.

• Imaging Science in Dentistry
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• 제32권3호
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• pp.159-165
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• 2002

Purpose: The aim of this study was to introduce a method of obtaining the oscillation graphs of the dental x-ray tube heads relative to time using an accelerometer. Materials and Methods: An Accelerometer, Piezotron type 8704B25 (Kistler Instrument Co., Amherst, NY, USA) was utilized to measure the horizontal oscillation of the x-ray tube head immediately after positioning the tube head for an intraoral radiograph. The signal from the sensor was transferred to a dynamic signal analyzer, which displayed the magnitude of the acceleration on the Y-axis and time lapse on the X -axis. The horizontal oscillation of the tube head was measured relative to time, and the settling time was also determined on the basis of the acceleration graphs for 6 wall type, 5 floor-fixed type, and 4 mobile type dental x-ray machines. Results : The oscillation graphs showed that tube head movement decreased rapidly over time. The settling time varied with x-ray machine types. Wall-type x-ray machines had a settling time of up to 6 seconds, 5 seconds for fixed floor-types, and 1 I seconds for the mobile-types. Conclusion: Using an accelerometer, we obtained the oscillation graphs of the dental x-ray tube head relative to time. The oscillation graph with time can guide the operator to decide upon the optimum exposure moment after x-ray tube head positioning for better radiographic resolution.

• 대한방사선기술학회지:방사선기술과학
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• 제38권3호
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• pp.199-203
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• 2015

한국에서의 파노라마장치의 사용비율은 치과대학병원에서 17.8%, 치과병원에서 24.8%, 치과의원에서 31.4%로 구내촬영장치 다음으로 많이 사용하고 있는 검사 방법으로, 치아교정 및 인플란트 등의 수요증가에 따라 파노라마 검사는 지속적으로 늘어나고 있는 추세이다. 본 연구에서는 파노라마 검사에 불필요한 안구와 갑상선부위의 선량을 감소시키기 위해 납안경 및 납차폐체를 이용해 보았으며, 납안경으로 차폐를 한 경우 안구의 ESD가 41.4% 감소되었으며, X선관 부위 쪽을 차폐납으로 차폐할 경우에는 ESD의 47.3%를 감소시킬 수 있음을 알게 되었다. eyeball의 불필요한 선량저감을 위하여 임상에서는 lead glass를 사용하는 방법이 있으며, 제조사에서는 eyeball부위 피폭을 줄일 수 있는 제어장치를 적극 활용할 필요성이 있는 것으로 나타났다.