• The Journal of the Korean dental association
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• v.54 no.9
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• pp.704-711
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• 2016

Radiologic images in dentistry are essential to perform the diagnosis, treatment, and tracking process of prognosis, thus the ability of accurate evaluation in the diagnostic images is requested for dental clinician. Radiologic interpretation means recognition of a normality and an abnormality and to report the possible diagnosis and differential diagnosis list. Therefore, dental clinicians should be familiar with the basic principle of interpretation of intraoral and extraoral radiographic images primarily used in dental clinics. Recently, dental cone beam CT is widely used for diagnositc process, thus understanding the three dimensional images is requested. The objective of this manuscript is to help the dental clinicians to interpret accurately the diagnostic images by introducing the basic principles of the step by step analytic process in the appearance of a lesion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.2
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• pp.93-98
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• 1993

Pleomorphic adenoma is the most common of all salivary gland tumors, constituting over 50% of all cases of tumors of both major and minor salivary gland origin and approximately 90% of all benign salivary gland tumors. Of the major salivary glands, the parotid gland is the most common site of the pleomorphic adenoma. It may occur, however, in any of the major gland or in the widely distributed intraoral accessory salivary glands. The palatal glands are frequently the site of origin of tumors, and other parts of origins are as follows: upper and lower lip, buccal mucosa, tongue and occasionally other sites. The majority of the lesions are found in patients in the fourth to sixth decades, but they are also relatively common in young adults and have been known to occur in children. It is somewhat more frequent in women than men. The term "mixed tumor" has masquaeraded under a great variety of names throughout the years (e.g., enclavoma, branchioma, endothelioma, enchondroma), but the term "pleomorphic adenoma" suggested by Willis characterizes closely the unusual histologic pattern of the lesion. The accepted treatment for this tumor is surgical excision. The intraoral lesions can be treated somewhat more conservatively by extracapsular excision. In general, Lesions of the hard palate should be excised with the overlying mucosa, while those in lining mucosa, such as the lips, soft palate and buccal mucosa often can be treated successfully by enucleation or extracapsular excision. In our hospital, we experienced two patients who were identified pleomorphic adenoma which occurred at buccal mucosa, submandibular gland. The lesions were successfully treated by surgical excision.

• Imaging Science in Dentistry
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• v.30 no.4
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• pp.265-274
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• 2000

Purpose: The aims of the present study are to determine the optimum compression rate in terms of file size reduction and diagnostic quality of the images after compression and evaluate the transmission speed of original or each compressed image. Materials and Methods: The material consisted of 24 extracted human premolars and molars. The occlusal surfaces and proximal surfaces of the teeth had a clinical disease spectrum that ranged from sound to varying degrees of fissure discoloration and cavitation. The images from Digora system were exported in TIFF and the images from conventional intraoral film were scanned and digitalized in TIFF by Nikon SF-200 scanner (Nikon, Japan). And six compression factors were chosen and applied on the basis of the results from a pilot study. The total number of images to be assessed were 336. Three radiologists assessed the occlusal and proximal surfaces of the teeth with 5-rank scale. Finally diagnosed as either sound or carious lesion by one expert oral pathologist. And sensitivity, specificity and k value for diagnostic agreement was calculated. Also the area (Az) values under the ROC curve were calculated and paired t-test and oneway ANOVA test was performed. Thereafter, transmission time of the image files of the each compression level was compared with that of the original image files. Results: No significant difference was found between original and the corresponding images up to 7% (1 : 14) compression ratio for both the occlusal and proximal caries (p<0.05). JPEG3 (1 : 14) image files are transmitted fast more than 10 times, maintained diagnostic information in image, compared with original image files. Conclusion: 1 : 14 compressed image file may be used instead of the original image and reduce storage needs and transmission time.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.2
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• pp.415-433
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• 1998

Digora system is an intraoral indirect digital radiography system utilizing storage phosphor image plate. It has wide dynamic range which allows it to decrease the patient s exposure time and may increase diagnostic ability through image processing (such as edge enhancement, grey scale conversion, brightness change, and contrast enhancement). And also, it can transmit and storage image information. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries between Conventional radiograph and Digora images(unenhanced image, brightness & contrast controlled image, and edge enhanced image). ROC(Receiver Operating Characteristic) analysis, paired t-tests, and F-tests were done for the statistical evaluation of detectability. The following results were acquired: 1. In Grade I lesions, the mean ROC areas of Conventional radiograph, Digora unenhanced image, Digora controlled image, and Digora edge enhanced image were 0.953, 0.933, 0.965, 0.978 (p>0.05). 2. In Grade II lesions, the mean ROC areas of Conventional radiograph, Digora unenhanced image, Digora controlled image, and Digora edge enhanced image were 0.969, 0.964, 0.988, 0.994. Among theses areas, there was just statistical significance between Diagnostic abilities of Digora edge enhanced image and Conventional radiograph (p<0.05). 3. In the Interobserver variability, the ROC curve areas of Digora edge enhanced image was lowermost in these areas, regardless of the Carious lesion depths. In conclusion, intraoral indirect digital system, Digora system, has the potential possibility as an alternative of Conventional radiograph in the diagnosis of proximal caries.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.2
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• pp.279-290
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• 1994

The purpose of this study was to compare the diagnostic accuracy of periapical radiographs and their digitized images for the detection of simulated interproximal carious lesions. A total of 240 interproximal surfaces was used in this study. The case sample was composed of 80 anterior teeth, 80 bicuspids and 80 molars which were prepared in order to distribute the surfaces from carious free to those containing simulated carious lesions of varying depths (0.5㎜, 0.8㎜, and 1.2㎜). The periapical radiographs were taken by paralleling technique and film used was Kodak Ektaspeed(E group). All radiographs were evaluated by five dentist to recognize the true status of simulated carious lesion. They were asked to give a score of 0, 1, 2, or 3. Digitized images were obtained using a commercial video processor(FOTOVIX Ⅱ- XS). And the computer system was 486 DX PC with PC Vision and frame grabber. The 17' display monitor had a resolution of 1280×1024 pixels(0.26㎜ dot pitch). But the one frame of the intraoral radiograph has a resolution of 700×480 pixels and each pixel has a grey level value of 256. All the radiographs and digital images were viewed under uniform subdued lighting in the same reading room. After a week the second interpretation was performed in the same condition. The detection of lesions on the monitor was compared with the finding of simulated interproximal carious lesions on the film images. The results were as follows: 1. When the scoring criteria was dichotomous ; lesion present and not present 1) The overall sensitivity, specificity and diagnostic accuracy of periapical radiographs and their digital images showed no statistically significant difference. 2) The sensitivity and specificity according to the region of teeth and the grade of lesions showed no statistically significant difference between periapical radiographs and their digital images. 2. When estimate the grade of lesions ; score 0, 1, 2, 3 1) The overall diagnostic accuracy was 53.3% on the intraoral films and 52.9% on digital images. There was no significant difference. 2) The diagnostic accuracy according to the region of teeth showed no statistically significant difference between periapical radiographs and their digital images. 3. The degree of agreement and reliability 1) Using gamma value to show the degree of agreement, there was similarity between periapical films and digital images. 2) The reliability of each twice interpretation of periapical films and digital images showed no statistically significant difference. In all cases P value was greater than 0.05, showing that both techniques can be used to detect the incipient and moderate interproximal carious lesions with similar accuracy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.6
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• pp.527-537
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• 2007

To evaluate criteria, indications, and prognosis of the various reconstructive methods on the patients with intraoral soft tissue defect who had been treated at Dept. of Oral and Maxillofacial Surgery, Pusan National University Hospital from 2003 to 2005, we have reviewed the clinical data of the patients and analysed. The results were as follows: 1. Tongue flaps have been mainly applied on anterior portion of palate and maxilla. The survival rate was high percent, but the cooperation of patient was inevitable for the success. 2. Palatal mucosa rotational flaps were available on relative large defect on palate, oroantral fistula site. The side effect was a scaring band from secondary healing on denuded donor palate site. Sometimes the band came to be a hinderance to swallowing, phonation. 3. Forearm free flap was a workhorse flap for everywhere in intraoral defects. We had used the flap on cheek, floor of mouth, tongue without any significant complications. But the application of the flap was required for long operation time, which was disadvantageous to the old, weak patients. 4. Cervical platysmal flap could be easily applicable for buccal cheek, floor of mouth after excision of the cancer lesion. The design of the flap could be made simultaneously on neck dissection, but the danger of cancer remnants on the flap always might be remained. 5. Buccal fat pad pedicled flap must have been a primary flap for repair of oroantral fistula especially on posterior maxilla. The flap survival will be expected if the considerations for above reconstructive methods on site, size, condition of defects primarily could be made.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.3
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• pp.68-73
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• 1990

Fibrous dysplasia is an idiopathic skeletal disorder in which medullary bone is replaced and disturbed by poorly organized, structually unsound fibroosseous tissue, which may produce cortical expansion. When facial bones are involed, considerable esthetic deformity may result. The term monostotic fibrous dysplasia has been applied when one bone is involved : when more than one bone is affected, the term polyostotic used. The polyostotic form may be accomplished by pigmented skin lesion (Jaffe type), or by pigmented skin lesions with endocrine disturbance (Albright syndrome). No general agreement exists on the cause of fibrous dysplasia. A few authors have suggested that fibrous dysplasia arises as a resujlt of trauma. It occurs predominantly in infant, adolescent females and runs a variable clinical course. When several bones are involed, it tends to be unilateral. Involements of alveolar bone may produce displacement of teeth with malocclusion, or loss of teeth, or both. Radiographycally, it shows an indistinctly delimited osteolytic defect with a bubble - like pattern, but without a sclerotic rim. The preferred treatment is almost always surgery. If the lesion is extensive, surgical intervention with use of recontouring procedures aimed at the correction of esthetic or funtional disturbances is preferred treatment. Now, we present a case of fibrous dysplasia on the left maxilla and the zygoma treated by bony contourign via hemicoronal flap and intraoral approach with good results.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.13 no.2
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• pp.91-94
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• 2017

Hypercementosis is an excessive deposition of secondary cementum on the root of a tooth. It is mostly presented as a solitary lesion or in rare cases as a generalized type, but which is seldom recognized; typically it is discovered during regular dental X-ray. Increased thickness of cementum is not uncommon but generalized hypercementosis on impacted permanent teeth which may cause delayed eruption is rarely reported. This case report discusses a patient with cerebral palsy, epilepsy and mental retardation that presents multiple hypercementosis with delayed eruption. On intraoral examination, multiple retained primary molar teeth were found. As there was no any further symptoms, regular dental checkup had been done for several years. In 2015, a surgical opening was performed in the second molar area, but there was no specific change. Panoramic view showed multiple impacted permanent teeth with increased thickness of roots due to excessive deposition of cementum. Hypercementosis was also observed in the root of the erupted tooth. Several laboratory test results including hormone, urine, complete blood count test were reviewed. The patient was also diagnosed with subclinical hypothyroidism, impaired fasting glucose and had been taken valproic acid($Orfil^{(R)}$) for 10 years. However, none of them clearly explained generalized hypercementosis or delayed eruption. The patient is now 24 years old and regular dental checkups and radiographs are taken to confirm that there is no change in the lesion.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.341-355
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• 1999

Squamous cell carcinoma is the most common type of oral cancer and odontogenic myxoma is relatively uncommon benign tumor of mesenchymal origin. There are, to our knowledge, no prior reports of simultaneously occurring squamous cell carcinoma and odontogenic myxoma of the jaw bones. In this case, at first, the plain films and computed tomograms revealed a large expansile multilocular radiolucent lesion on left mandible and marked expansion of cortical plate. In addition this radiograms revealed also infiltrative bony destruction of anterior and medial border of ascending ramus of left mandible and alveolar bone of left maxilla, floating teeth on left lower molar area and metastatic enlargement of left submandibular, jugular digastric and spinal accessory lymphnodes. Magnetic resonance imaging of this patient revealed infiltrative growth of tumor on alveolar bone of left maxilla, left retromolar fat pad. left masseter and left medial pterygoid muscle. Intraoral presurgical biopsy presented typical features of squamous cell carcinoma. After chemotherapy with radiation therapy during 6 months. this central lesion was diagnosed as odontogenic myxoma by the postsurgical biopsy. After 3 months, this patient presented multiple metastatic signs at lumbar spines, rib and liver. Consequently, our case is simultaneous occurrence of squamous cell carcinoma and odontogenic myxoma.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.533-538
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• 1998

[ $Garr{\grave{e}}'s$ ] osteomyelitis is a chronic form of osteomyelitis in which periosteum is thickened with peripheral reactive bone formation. Carl $Garr{\grave{e}}$ first reported localized periosteal thickening as a response to mild stimuli. In dental literatures, Pell et al. first reported $Garr{\grave{e}}'s$ osteomyelitis in jaws. This disease frequent occurs in youngsters and usually in mandible. It usually results in hard swelling over the jaws with little or no pain. Palpation reveals a localized bony swelling lesion. In radiographic findings, it usually reveals laminated periosteal thickening on lesion. The treatment of $Garr{\grave{e}}'s$ osteomyelitis usually consists of elimination of the sources of infection, i.e., either extraction of an infected teeth or root canal therapy. Two children were admitted with the chief complaint of intraoral swelling on lower deciduous molar areas which was diagnosed as $Garr{\grave{e}}'s$ osteomyelitis. The root canal therapy and antibiotic therapy were performed and prognosis was checked. From these case studies, some results were obtained as follows : With the aid of root canal therapy and antibiotic administration, the size of periapical lesions was reduced, the mandible with bony swelling recovered its normal shapes radiographically, and the permanent tooth germs resumed sound development.