• Imaging Science in Dentistry
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• v.36 no.3
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• pp.131-135
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• 2006

Purpose : To evaluate the true projection angles of film-side mandibular condyles in panoramic and transcranial radiographs. Materials and Methods : 52 panoramic and transcranial radiographs of 4 condyles from two human dry mandibles with gradual horizontal and vertical angle changes were taken. The results were compared with the standard panoramic and transcranial radiographs and the identical pairs were selected. Results and Conclusion : Panoramic radiography projected 10 degrees to the film-sided condyles both horizontally and vertically. Transcranial radiography projected 15 degrees to the film-sided condyles vertically. The medial and lateral poles were not forming the outline of condylar images in both projections when the horizontal angles of condyles were not sufficiently big enough.

• Imaging Science in Dentistry
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• v.46 no.1
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• pp.47-51
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• 2016

Herein, we report and discuss the detection of fossa navicularis magna, a close radiographic anatomic variant of canalis basilaris medianus of the basiocciput, as an incidental finding in cone-beam computed tomography (CBCT) imaging. The CBCT data of the patients in question were referred for the evaluation of implant sites and to rule out pathology in the maxilla and mandible. CBCT analysis showed osseous, notch-like defects on the inferior aspect of the clivus in all four cases. The appearance of fossa navicularis magna varied among the cases. In some, it was completely within the basiocciput and mimicked a small rounded, corticated, lytic defect, whereas it appeared as a notch in others. Fossa navicularis magna is an anatomical variant that occurs on the inferior aspect of the clivus. The pertinent literature on the anatomical variations occurring in this region was reviewed.

• Imaging Science in Dentistry
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• v.41 no.3
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• pp.107-113
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• 2011

Purpose : The purpose of this study was to present the clinical features of a case series of osteomas in the craniofacial region and to compare them with those described in the dental literatures. Materials and Methods : A retrospective study of 18 patients diagnosed with osteomas in the craniofacial region was performed. The age, gender, location, symptoms, and the radiological findings were recorded. Results : There were 13 women and 5 men from 18 years to 69 years of age (mean age, $42{\pm}27$ years). Fourteen osteomas were found in the mandible (78%), two in frontal sinus, one in sphenoid bone, and one in maxilla. Conclusion : Osteomas are benign tumors composed of mature compact bone or cancellous bone. They are essentially restricted to the craniofacial skeleton and rarely, if ever, are diagnosed in other bones.

• Imaging Science in Dentistry
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• v.48 no.4
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• pp.283-287
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• 2018

Craniometaphyseal dysplasia (CMD) is a rare hereditary disorder characterized by hyperostosis of the craniofacial bones and flared metaphyses of the long bones. Although some reports have described the dentomaxillofacial characteristics of CMD, including increased density of the jaw, malocclusion, and delayed eruption of the permanent teeth, only a few studies have reported the distinct imaging features of CMD on panoramic radiography. This report presents 2 cases of confirmed CMD patients with an emphasis on panoramic imaging features. The patients' images revealed hyperostosis and sclerosis of the maxilla and mandibular alveolar bone, but there was no change in the mandibular basal bone. In both cases, the mandibular condyle heads exhibited a short clubbed shape with hyperplasia of the coronoid process. For patients without clear otorhinolaryngological symptoms, common radiologic features of CMD could be visualized by routinely-taken panoramic radiographs, and further medical examinations and treatment can be recommended.

• Imaging Science in Dentistry
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• v.53 no.3
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• pp.239-245
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• 2023

Schwannomas are uncommon neoplasms of neurologic origin that are rare in the salivary glands. A schwannoma that persists for a long time is referred to as an ancient schwannoma if it is accompanied by degenerative changes on histology. The case described herein involved a 37-year-old man with an ancient schwannoma that had persisted for 20 years in his right parotid gland. Clinically, the lesion presented with swelling and pain. Computed tomography revealed a well-defined, multilocular enhanced lesion. T2-weighted magnetic resonance images displayed multilocular hyperintensity, while T1-weighted images showed a high signal at the lobulated margin and a homogeneous low signal internally. The preoperative diagnosis, based on the lesion's location and imaging diagnosis, was Warthin's tumor. However, a biopsy conducted after surgical excision identified the lesion as a schwannoma with cystic degeneration. This report also presents a summary of the characteristics of rare cases of schwannoma in the major salivary gland based on this case and a literature review.

• Imaging Science in Dentistry
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• v.53 no.4
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• pp.383-388
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• 2023

Simple bone cyst is a pseudocyst that typically occurs in patients during their second and third decades of life. This benign entity is an empty or fluid-filled cavity that lacks a true epithelial lining. Simple bone cysts are often asymptomatic and are commonly found in mandibular body, predominantly in the posterior region. The treatment of simple bone cysts can be influenced by factors such as the patient's age, the size of the lesion, and the presence or absence of symptoms. In the case of a simple bone cyst in the mandible that is small and symptomless, a watchful waiting approach may be appropriate. However, if the cyst is large and symptomatic, surgical treatment is recommended. This report presents a radiological examination of a simple bone cyst that developed around the root of the mandibular first molar in a 36-year-old female patient. The cyst recurred in adjacent areas despite surgical treatment.

• Imaging Science in Dentistry
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• v.54 no.1
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• pp.105-107
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• 2024

The author herein presents an unusual case of eustachian tube calcification masquerading as loose radiopacities in the temporomandibular joints on a panoramic image, creating a diagnostic challenge. The patient, a 72-year-old woman, presented to the dental service for implant treatment to improve her masticatory function. A cone-beam computed tomography scan was performed and reviewed by a board-certified oral and maxillofacial radiologist. The scan showed no evidence of calcifications in the temporomandibular joints; however, it revealed nodular calcifications within the cartilaginous portion of the eustachian tube bilaterally. Additionally, this report briefly reviews the differential diagnosis of calcified loose bodies in the temporomandibular joint and provides information that needs to be reinforced periodically.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.217-223
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• 2014

The aim of this study is evaluation of dose distribution on radiation therapy planning system with the CT image of high-density material inserted phantom. Gammex 467 Tissue Characterization Phantom is used to acquire an image similar to the human tissues and insert a Titanium to generate metal artifact. The acquired images were reconstructed with Metal Artifact Reduction for Orthopedic Implants (O-MAR). By using the treatment planning system, the volume was analyzed and dose distribution was extracted. Photon dose distribution in linear accelerator was measured by the $MapCHECK^{TM}$ and compared with planned and measured dose distributions. In result of the comparative analysis, when artifact is generated by Titanium, The volume applied O-MAR was increased 6.8% to BR-12 Breast and 40.2% to LV 1 Liver. After O-MAR was used, Dose distribution was higher 1.4 to 1.6% than before. Consequently, The artifact caused by metal objects should be removed if possible, and after that used in the radiotherapy treatment plan can be considered to reduce errors.

• Journal of radiological science and technology
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• v.31 no.3
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• pp.217-222
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• 2008

Radiation dose to radiologists working at three hospitals in Seoul was investigated from Jan 1, 2006 to Dec. 31, 2006. The results are as follows. First, radiation dose to radiologists at a cardiac angiography room was measured as 1.41mSv, the highest while radiation dose to radiologists at a department of radiation oncology was measured as 0.64 mSv, the lowest. Second, radiation dose proves to be in direct proportion to the number of X-ray treatment. Third, as for the radiation dose in X-ray treatments, radiologists in cardiac angiography room are exposed to the largest amount of radiation while radiologists in diagnostic radiology department are exposed to the smallest amount of radiation. Last, radiation dose at a cardiac angiography room is the largest and is followed by nuclear medicine, diagnostic radiology, and radiation oncology departments in order. According to ICRP, exposure less than 20mSv per year is highly recommended while radiation dose is allowed as long as it is ranged less than 50mSv per year or 100mSv within a 5-year period. Taking into account the results, radiation exposure does not do any harm to radiologists at any related departments in Korean hospitals because the dose per year is less than 1.60mSv.

• Imaging Science in Dentistry
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• v.54 no.2
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• pp.129-137
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• 2024

Purpose: Patients with head and neck cancer (HNC) who undergo dental procedures during radiotherapy (RT) face an increased risk of developing osteoradionecrosis (ORN). Accordingly, new tools must be developed to extract critical information regarding the dose delivered to the teeth and mandible. This article proposes a novel approach for visualizing 3-dimensional planned dose distributions on panoramic reconstruction computed tomography (pCT) images. Materials and Methods: Four patients with HNC who underwent volumetric modulated arc therapy were included. One patient experienced ORN and required the extraction of teeth after RT. In the study approach, the dental arch curve (DAC) was defined using an open-source platform. Subsequently, pCT images and dose distributions were generated based on the new coordinate system. All teeth and mandibles were delineated on both the original CT and pCT images. To evaluate the consistency of dose metrics, the Mann-Whitney U test and Student t-test were employed. Results: A total of 61 teeth and 4 mandibles were evaluated. The correlation coefficient between the 2 methods was 0.999, and no statistically significant difference was observed (P>0.05). This method facilitated a straightforward and intuitive understanding of the delivered dose. In 1 patient, ORN corresponded to the region of the root and the gum receiving a high dosage (approximately 70 Gy). Conclusion: The proposed method particularly benefits dentists involved in the management of patients with HNC. It enables the visualization of a 3-dimensional dose distribution in the teeth and mandible on pCT, enhancing the understanding of the dose delivered during RT.