• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.27 no.1
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• pp.243-249
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• 1997

Adenoid cystic carcinoma is a malignant salivary gland tumor with typical histologic patterns. The majority of these tumors occurs in the minor salivary glands. especially mucosa of the hard palate. The authors experienced the patients, who complained the tumor-like soft tissue masses on the palatal and mouth floor area. After careful analysis of clinical, radiological and histopathological findings, we diagnosed them as adenoid cystic carcinomas in the minor salivary glands, and obtained results were as follows : 1. Main clinical symptoms were a slow growing soft tissue mass with normal intact mucosa on the palatal area, and soft tissue mass with mild pain on the mouth floor area. 2. In the radiographic exarnminations, soft tissue masses were observed with invasion to adjacent structures, and moderate defined, heterogeneous soft tissue mass with enhanced margin, respectively. 3. In the histopathologic exarnminations, dark-stained, small uniform basaloid cells in the hyaline or fibrous stroma were observed as solid and cribriform patterns, respectively.

• Imaging Science in Dentistry
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• v.41 no.4
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• pp.167-170
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• 2011

Ellis-van Creveld syndrome is a rare congenital genetic disorder having autosomal recessive inheritance. It is a syndrome affecting the Amish population of Pennsylvania in USA with prevalence rate of 1/5,000 live at birth. In non-Amish population, the birth prevalence is 7/1,000,000. The syndrome is characterized by bilateral postaxial polydactyly of the hands, chondrodysplasia of long bones resulting in acromesomelic dwarfism, ectodermal dysplasia affecting nails as well as teeth and congenital heart malformation. There were very rare reports of this syndrome in dentistry. The present case focuses on the striking and constant oral findings of these patients, which are the main diagnostic features of this syndrome. Since the oral manifestations affect the esthetic, speech, and jaw growth of the child, the dentists have an important role to play in proper management of such case.

• Imaging Science in Dentistry
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• v.43 no.4
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• pp.303-308
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• 2013

This report describes a 31-year-old female patient with six impacted teeth. The crowns of the impacted teeth were surrounded with cyst-like lesions with a mixed internal structure and well-defined cortical borders. Microscopic examination of the specimen obtained from the follicle of the left mandibular third molar tooth revealed loose to moderately dense collagenous connective tissue with abundant calcified material and sparse epithelial islands. A diagnosis of multiple calcifying hyperplastic dental follicles was made.

• Imaging Science in Dentistry
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• v.50 no.4
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• pp.373-376
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• 2020

This report presents a rare case of ameloblastoma with histopathologic and radiographic calcification, including 3-dimensional cone-beam computed tomographic (CBCT) images. A 22-year-old woman had hard swelling on the right mandible. Panoramic and CBCT images showed multilocular radiolucencies with internal calcification foci in the right mandible. Three-dimensional images clearly showed varying-sized radiopacities within the lesion from various angles. A histopathologic examination showed central squamous differentiation and more densely packed peripheral palisading ameloblastic cells. Many areas of keratin pearls and calcifications were also seen. Four previous reports have described 5 cases of ameloblastoma showing histopathologic calcification. This might be the first report to present the calcification of ameloblastoma on panoramic and CBCT images, especially on 3-dimensional images.

• Imaging Science in Dentistry
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• v.32 no.3
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• pp.167-173
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• 2002

Purpose : To evaluate clinical and radiographic differential diagnosis between ameloblastoma and odontogenic keratocyst (OKC) using clinical data, plain radiographs, and CT. Materials and Methods: 25 cases of ameloblastoma and 44 cases of OKC diagnosed in biopsy, were selected from the files stored in Department of Oral and Maxillofacial Radiology, Seoul National University Dental Hospital from 1999 to 2001, and evaluated using following criteria: sex and age, location, shape, border to normal bone tissue, effect to adjacent tissues, homogeneity in the lumen of the lesion, response of the cortical bone, long-to-short length (LIS) ratio of the lesion, and expansion angle of the cortex. Results: Ameloblastoma and OKC were seen most frequently in third decades and no statistical significance was noted between both sexes. Ameloblastoma occurred most frequently in mandibular angle and ramus area (68%) and OKC at the maxillary molar (34.1 %), and mandibular angle and ramus area (43.2%). The root resorption of the adjacent teeth, mandibular canal displacement, and the impaction of teeth were seen more frequently in ameloblastoma than in OKC. The LIS ratio measured in CT was largest in maxillary OKC cases, followed by mandibular ameloblastoma, and mandibular OKC (1.2, 1.8 and 2.4 respectively). The expansion angle of the cortex shows a statistically significant difference between ameloblastoma (48.8°) and OKC (31.5°). Conclusion : The numeric morphology (LIS ratio) and expansion angle of the cortical bone of the lesion measured in computed tomography can be used to differentiate the ameloblastoma and odontogenic keratocyst.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.25-32
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• 2006

Purpose : To investigate the validity of digital image processing on panoramic radiographs in estimating bone quality before endosseous dental implant installation by correlating bone quality in radiographic images with clinical bone quality classification. Materials and Methods : An experienced surgeon assessed and classified bone quality for implant sites with tactile sensation at the time of implant placement. Including fractal dimension eighteen morphologic features of trabecular pattern were examined In each anatomical sites on panoramic radiographs. Finally bone quality of 67 implant sites were evaluated in 42 patients. Results : Pearson correlation analysis showed that three morphologic parameters had weak linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.276, -0.280, and - 0.289, respectively (p<0.05). And other three morphologic parameters had obvious linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.346, -0.488, and -0.343 respectively (p<0.05). Fractal dimension also had a linear correlation with clinical bone quality classification with correlation coefficients -0.506 significantly (p<0.05). Conclusion : This study suggests that fractal and morphometric analysis using digital panoramic radiographs can be used to evaluate bone quality for implant recipient sites.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.139-146
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• 2012

Purpose: An individual surgical stent fabricated from computed tomography (CT) data, called a CT-guided stent, would be useful for accurate installation of implants. The purpose of the present study was to introduce a newly developed CT-guided stent with a simple design and evaluate the accuracy of the stent placement. Materials and Methods: A resin template was fabricated from a hog mandible and a specially designed plastic plate, with 4 metal balls inserted in it for radiographic recognition, was attached to the occlusal surface of the template. With the surgical stent applied, CT images were taken, and virtual implants were placed using software. The spatial positions of the virtually positioned implants were acquired and implant guiding holes were drilled into the surgical stent using a specially designed 5-axis drilling machine. The surgical stent was placed on the mandible and CT images were taken again. The discrepancy between the central axis of the drilled holes on the second CT images and the virtually installed implants on the first CT images was evaluated. Results: The deviation of the entry point and angulation of the central axis in the reference plane were $0.47{\pm}0.27$ mm, $0.57{\pm}0.23$ mm, and $0.64{\pm}0.16^{\circ}$, $0.57{\pm}0.15^{\circ}$, respectively. However, for the two different angulations in each group, the $20^{\circ}$ angulation showed a greater error in the deviation of the entry point than did the $10^{\circ}$ angulation. Conclusion: The CT-guided template proposed in this study was highly accurate. It could replace existing implant guide systems to reduce costs and effort.

• Imaging Science in Dentistry
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• v.53 no.3
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• pp.257-263
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• 2023

Fibrodysplasia ossificans progressiva is a rare hereditary disorder characterized by progressive heterotopic ossification in muscle and connective tissue, with few reported cases affecting the head and neck region. Although plain radiographic findings and computed tomography features have been well documented, limited reports exist on magnetic resonance findings. This report presents 2 cases of fibrodysplasia ossificans progressiva, one with limited mouth opening due to heterotopic ossification of the lateral pterygoid muscle and the other with restricted neck movement due to heterotopic ossification of the platysma muscle. Clinical findings of restricted mouth opening or limited neck movement, along with radiological findings of associated heterotopic ossification, should prompt consideration of fibrodysplasia ossificans progressiva in the differential diagnosis. Dentists should be particularly vigilant with patients diagnosed with fibrodysplasia ossificans progressiva to avoid exposure to diagnostic biopsy and invasive dental procedures.

• Journal of Korean society of Dental Hygiene
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• v.10 no.1
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• pp.197-213
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• 2010

Objectives : This research identified the frequency and satisfaction level of the observation and performance practice during the clinical practice process conducted by dental hygiene students. With the goal of providing base data required for the development and operation of increasingly effective clinical practice program and for the improvement of the existing clinical practice training. Methods : The subjects in this study were 278 students of a university located in Masan. Survey comprised of 49 questions in 10 clinical practice domains was conducted. Results : 1. As for the observation practice by each grade, there was significant difference in oral radiology, pediatric dentistry, periodontology, oral surgery(p<0.05). As for the performance practice executed for each grade, there was significant difference in the oral radiology, preventive dentistry and oral surgery(p<0.05). As for the satisfaction level for each grade, there was significant difference in basic medical service(p<0.05). 2. As for the observation practice by each clinical practice institution, there was significant difference in oral medicine, oral radiology, preventive dentistry, prosthodontics, pediatric dentistry, orthodontics and oral surgery(p<0.05). As for the performance practice executed by each practice institution, there was significant difference in basic medical service, oral medicine, oral radiology, operative dentistry, prosthodontics, orthodontics, oral surgery(p<0.05). As for the satisfaction level by each practice institution, there was significant difference in the oral radiology, preventive dentistry, operative dentistry, prosthodontics, orthodontics, oral surgery(p<0.05). Conclusions : As for the satisfaction level for the clinical practice, basic medical service is the crimary care clinical practice which is most basic and that is executed the most in a dental clinic. Satisfaction level was the highest in the domains where there were extensive observation and practice frequency. By conducting observation and practice frequency in the clinical practice process by each clinical practice domain in a broad and diverse manner, it would be possible to improve the ability of the clinical practice trainees who improve their clinical work execution capability and satisfaction level on the clinical practice.

• Imaging Science in Dentistry
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• v.45 no.3
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• pp.175-180
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• 2015

Purpose: This study was performed to evaluate the reliability of the identification of anatomical landmarks in panoramic and lateral cephalometric radiographs on a standard medical grade picture archiving communication system (PACS) monitor and a tablet computer (iPad 5). Materials and Methods: A total of 1000 radiographs, including 500 panoramic and 500 lateral cephalometric radiographs, were retrieved from the de-identified dataset of the archive of the Section of Oral and Maxillofacial Radiology of the University Of Connecticut School Of Dental Medicine. Major radiographic anatomical landmarks were independently reviewed by two examiners on both displays. The examiners initially reviewed ten panoramic and ten lateral cephalometric radiographs using each imaging system, in order to verify interoperator agreement in landmark identification. The images were scored on a four-point scale reflecting the diagnostic image quality and exposure level of the images. Results: Statistical analysis showed no significant difference between the two displays regarding the visibility and clarity of the landmarks in either the panoramic or cephalometric radiographs. Conclusion: Tablet computers can reliably show anatomical landmarks in panoramic and lateral cephalometric radiographs.