Recurrent odontogenic keratocyst within the masticatory space / 대한구강악안면방사선학회지

The odontogenic keratocyst (OKC) is a developmental odontogenic cyst typically occurring in the jaws. Since the first description of OKC was published in 1956, the lesion has been of particular interest because of its specific histopathologic features, high recurrence rate, and aggressive behavior. Recurrences most commonly arise within bone at the site of the original cyst. However, as lining cells may find their way into surrounding tissues either from implantation during surgery or from cortical perforation recurrences may arise at a distance from the original cyst. Here, we report a rare case of recurrent OKC which was first developed in mandible and recurred within the masticatory space.

Evaluation of the postoperative maxillary sinus with computed tomography / 대한구강악안면방사선학회지

PURPOSE: To evaluate the computed tomographic appearances of postoperative maxillary sinuses. MATERIALS AND METHODS: 33 asymptomatic cases of post-operative maxillary sinus without evidence of any patho-logic changes and clinical symptoms were selected. CT images were classified as opacification, soft tissue shadow, anterior wall depression, naso-antral communication, and compartmentalization. The relationships between the CT image and the age of patients at the time of operatation, and between the CT image and the duration of time elapsed since the surgical procedure were evaluated. RESULTS: The most commonly presented radiological characteristics that occurred after the Caldwell-Luc procedure were opacification and soft tissue shadow. Anterior wall depression and naso-antral communication were radiographic indications that a Caldwell-Luc operation had been carried out. The age of patients when they had been first operated on, and the duration between the surgical procedure and the time of evaluation had no effect on the CT appearances of normal changes. In cases involving a longer time interval between the antral surgery and evaluation, the anterior wall depression with bony healing was more commonly observed than soft tissue healing. CONCLUSION: The radiographic information regarding the normal healing state using computed tomography can distinguish post-operative changes from inflammatory and cystic disease in patients who have undergone a Caldwell-Luc type of radical maxillary antrostomy.

Reproducibility of lateral cephalometric landmarks on conventional radiographs and spatial frequency-processed digital images / 대한구강악안면방사선학회지

PURPOSE: Computed radiography (CR) has been used in cephalometric radiography and many studies have been carried out to improve image quality using various digital enhancement and filtering techniques. During CR image acquisition, the frequency rank and type affect to the image quality. The aim of this study was to compare the diagnostic quality of conventional cephalometric radiographs to those of computed radiography. MATERIALS AND METHODS: The diagnostic quality of conventional cephalometric radiographs (M0) and their digital image counterparts were compared, and at the same time, six modalities (M1-M6) of spatial frequency-processed digital images were compared by evaluating the reproducibility of 23 cephalometric landmark locations. Reproducibility was defined as an observer's deviation (in mm) from the mean between all observers. RESULTS AND CONCLUSION: In comparison with the conventional cephalometric radiograph (M0), M1 showed statistically significant differences in 8 locations, M2 in 9, M3 12, M4 in 7, M5 in 12, and M6 showed significant differences in 14 of 23 landmark locations (p<0.05). The number of reproducible landmarks that each modality possesses were 7 in M6, 6 in M5, 5 in M3, 4 in M4, 3 in M2, 2 in M1, and 1 location in M0. The image modality that observers selected as having the best image quality was M5.

The effect of retinoic acid on radiosensitivity analyzed by linear-quadratic model and apoptosis in head and neck squamous carcinoma cell lines / 대한구강악안면방사선학회지

PURPOSE: To evaluate the effect of all-trans-retinoic acid on radiosensitivity and radiation-induced apoptosis in NHOK, HEp-2 and FaDu cell lines. Material and Methods : We measured the changes in survival fraction at 2 Gy (SF2), alpha and beta after treatment of retinoic acid (1 microM) prior to irradiation with doses of 2, 4, 6 and 10 Gy and correlated the radiosensitizing effect of retinoic acid with them. Also, apoptosis induction was assayed with the flow cytometry on days 1, 2, 3, 4 and 5 after irradiation (2, 10 and 20 Gy) combined with retinoic acid. Results and CONCLUSION: SF2 values for NHOK, HEp-2 and FaDu cell lines were 0.54, 0.64 and 0.41, respectively and the cell line of FaDu was the most radiosensitive. For cell lines of NHOK and HEp-2, pretreatment of cells with retinoic acid resulted in a significant decrease of the SF2 values. The alpha/betaratios of x-ray survival curve were 8.714 (NHOK), 4.098 (HEp-2) and 11.79 (FaDu). The alpha/beta ratio for NHOK decreased on pretreatment with retinoic acid, whereas those for HEp-2 and FaDu increased. Radiation induced apoptosis in all cell lines but, retinoic acid did not affect the apoptosis.

Squamous cell carcinoma in the submandibular space / 대한구강악안면방사선학회지

A 66-year-old man visited author's institute complaining of the swelling on the submandibular gland area. Clinically, the exophytic mass penetrated the skin of the submandibular area. On MRI, the lesion occupied the left submandibular space and extended downward, protruding exterior to the subcutaneous fat layer, but the center of the lesion was located on the side of the skin and the growth exterior to the skin was prominent. Demarcation of the lesion and the submandibular gland was unclear. Histopathologically the epithelial nests and keratin production were seen, then the biopsy result was squamous cell carcinoma. The stroma of lesion showed a myxoid characteristic and some ducts showed metaplasia of the ductal cells, which suggested the gland-origin carcinoma. However, lots of keratin production and carcinomatous change of cells continuous to the normal epithelium of the skin, the skin-origin carcinoma invading into the submandibular gland area could not be excluded.

Squamous cell carcinoma in the submandibular space / 대한구강악안면방사선학회지

A 66-year-old man visited author's institute complaining of the swelling on the submandibular gland area. Clinically, the exophytic mass penetrated the skin of the submandibular area. On MRI, the lesion occupied the left submandibular space and extended downward, protruding exterior to the subcutaneous fat layer, but the center of the lesion was located on the side of the skin and the growth exterior to the skin was prominent. Demarcation of the lesion and the submandibular gland was unclear. Histopathologically the epithelial nests and keratin production were seen, then the biopsy result was squamous cell carcinoma. The stroma of lesion showed a myxoid characteristic and some ducts showed metaplasia of the ductal cells, which suggested the gland-origin carcinoma. However, lots of keratin production and carcinomatous change of cells continuous to the normal epithelium of the skin, the skin-origin carcinoma invading into the submandibular gland area could not be excluded.

Subarachnoid Hemorrhage with Negative Initial Angiography

In 614 of 793 cases with subarachnoid hemorrhage(SAH), four vessel cerebral angiography was performed to investigate the source of the hemorrhage. The first four vessel study revealed 501 cases of ruptured cerebral aneurysms; during initial pan-angiography studies, 113 SAH patients did not show vascular lesions. Thirty two of 71 patients(45.1%) showed aneurysms on repeat angiography: fifteen of them had aneurysms in the anterior communicating artery. Among patients whose Hunt Hess grade on admission was poor(III-IV), the possibility of revealing aneurysm during repeated angiography was higher than in those whose grade was good(I-II)(p<0.05, Fisher exact test). On repeat angiography, the age, sex and CT grade of patients with aneurysm were indistinguishable from those of patients without: even in those who on initial angiography showed angiographic vasospasm, the chance of revealing an aneurysm was the same as in those without spasm. We concluded that repeated angiography, especially after 3 weeks of ictus, was valuable for the detection of an initially undefined aneurysm.

Radiation effect on the stages of amelogenesis in the rat incisor / 대한구강악안면방사선학회지

The purpose of this study was to investigate the radiation effect on the stages of amelogenesis. Twenty 11-day-old rats which were irradiated by 4GY of gamma radiation on the 19th prenatal day were used for the experimental group and twenty 11-day-old rats which were not irradiated were used for the control group. The length of each zone of amelogenesi s were measured on the sagittal section using a light microscopic enlargement at 400 X the normal view while the morphol ogic changes of ameloblasts of each zone were observed electron-microscopically. The obtined results were as followed: 1. The length of the region of facing pulp and facing dentin of the zone of presecretion were increased by 11.5%(P0.05). 4. Electron-microscopically, enlargement of the cell membrane, rER, mitochondria, and nuclear membrane were observed. These changes were mostly severe in the zone of maturation.

Radiation effect on the stages of amelogenesis in the rat incisor / 대한구강악안면방사선학회지

The purpose of this study was to investigate the radiation effect on the stages of amelogenesis. Twenty 11-day-old rats which were irradiated by 4GY of gamma radiation on the 19th prenatal day were used for the experimental group and twenty 11-day-old rats which were not irradiated were used for the control group. The length of each zone of amelogenesi s were measured on the sagittal section using a light microscopic enlargement at 400 X the normal view while the morphol ogic changes of ameloblasts of each zone were observed electron-microscopically. The obtined results were as followed: 1. The length of the region of facing pulp and facing dentin of the zone of presecretion were increased by 11.5%(P0.05). 4. Electron-microscopically, enlargement of the cell membrane, rER, mitochondria, and nuclear membrane were observed. These changes were mostly severe in the zone of maturation.

A Case of Frontal Gliosarcoma

The authors report a case of frontal gliosarcoma. The characteristic of this tumor is that it is composed of mixed glial and sarcomatous elements. The sarcomatous elements are thought to derive from the neoplastic transformation of mesenchymal cells in or adjacent to the tumor. This transformation usually has the appearance of a fibrosarcoma or angiosarcoma. A 24-year-old man had a 1-month history of headache, dizziness followed by blurred vision. At admission, there was no focal neurological deficit except bilateral papilledema. Brain CT and MRI revealed a heterogeneously enhancing mass containing cystic portion in the right frontal lobe with considerable peritumoral edema and shift of the midline structures. A craniotomy was performed with gross total resection of the tumor. Postoperative course was uneventful with resolution of his symptoms. The histologic, immunohistochemical and electron microscopy studies revealed bimorphic pattern, a characteristic feature of gliosarcoma.