Effects of irradiation on the mRNA expression of the osteocalcin and osteopontin in MC3T3-E1 osteoblastic cell line / 대한구강악안면방사선학회지

PURPOSE: To investigate the effects of irradiation on the phenotypic expression of the MC3T3-E1 osteoblastic cell line, particularly on the expression of osteocalcin and osteopontin. MATERIALS AND METHODS: Cells were irradiated with a single dose of 0.5, 1, 4, and 8 Gy at a dose rate of 5.38 Gy/min using a cesium 137 irradiator. After the specimens were harvested, RNA was extracted on the 3rd, 7th, 14th, and 21st day after irradiation. The RNA strands were reverse-transcribed and the resulting cDNAs were subjected to amplification by PCR. RESULTS: The irradiated cells demonstrated a dose-dependent increase in osteocalcin and a dose-dependent decrease in osteopontin mRNA expression compared with the non-irradiated control group. The amount of osteocalcin mRNA expression decreased significantly at the 3rd day after irradiation of 0.5, 1, 4, and 8 Gy, and also decreased significantly at the 3rd, 14th, and 21st day after irradiation in the 8 Gy exposed group compared with the control group. The degree of osteopontin mRNA expression increased significantly at the 7th day after irradiation of 0.5, 1, 4, and 8 Gy. CONCLUSION: These results showed that each single dose of 0.5, 1, 4, and 8 Gy influenced the mRNA expression of osteocalcin and osteopontin associated with the calcification stage of osteoblastic cells, suggesting that each single dose affected bone formation at the cell level.

Transcranial radiograph and magnetic resonance imaging in the evaluation of osseous changes of the temporomandibular joint / 대한구강악안면방사선학회지

PURPOSE: To evaluate the diagnostic accuracy of transcranial radiographs and magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) in the assessment of osseous changes of the condylar head and articular eminence. MATERIALS AND METHODS: Osseous changes of the TMJ were evaluated in forty-three patients. Osseous changes of the condylar head and articular eminence were observed in 41 joints and 64 joints, respectively on transcranial radiographs, and 48 joints and 59 joints, respectively on MRI. RESULTS: The flattening, sclerosis, erosion, and osteophyte formation of the condylar heads were observed in 36.6%, 43.9%, 12.2%, and 7.3%, respectively on transcranial radiographs compared with 35.4%, 20.8%, 37.5%, and 6.3%, respectively on MRI. While, the flattening, sclerosis, and erosion of the articular eminences were observed in 26.6%, 67.2%, and 6.2%, respectively on transcranial radiographs compared with 32.2%, 59.3%, and 8.5%, respectively on MRI. CONCLUSION: There were no statistical differences between transcranial radiographs and MRI scans in the detection of osseous changes of the TMJ. However, MRI scans were superior to the transcranial radiographs in the detection of erosion of the condylar head (p<0.01).

Evaluation of osseous changes of TMJ in internal derangement and osteoarthritis patients using MRI / 대한구강악안면방사선학회지

PURPOSE: To evaluate the osseous changes of TMJ in internal derangement and osteoarthritis patients using MRI. MATERIALS AND METHODS: MR images of 111 TMJs in 64 patients were analyzed to evaluate the osseous changes. 111 TMJs were divided into 6 groups according to the radiologic Stages by Schellhas and Wilkes. On MR images, we evaluate the osseous changes of articular eminence and condylar head. RESULTS: The most frequent Stage in internal derangement of TMJ was Stage I. And 28 joints (25.2%) revealed osteoarthritis with internal derangement. When osseous change of articular eminence and condylar head occur, flattening was the most common osseous change. Sclerosis was observed in all Stages and osteophytosis of condylar head was observed in Stage II (1.8%) and III (0.9%). Out of 28 joints with osteoarthritis, 6 joints (21.4%) showed joint effusion. CONCLUSION: MR image revealed abnormal configuration of disk, but the detection of minimal osseous change was subtle.

Positional and morphologic changes of the temporomandibular joint disc using magnetic resonance imaging / 대한구강악안면방사선학회지

PURPOSE: To evaluate displacement and morphologic changes of the temporomandibular joint (TMJ) disc in patient with internal derangement using magnetic resonance imaging (MRI). MATERIALS AND METHODS: One hundred and forty five MR images of TMJs in 73 patients were evaluated. Positional and morphologic changes of the TMJ discs were assessed. Lateral or medial disc displacement was also evaluated on coronal images. RESULTS: Among 63 discs with anterior disc displacement, 37 discs were assessed as a biconcave disc and 21 as a deformed disc. Rotational disc displacement was observed in 35 discs. Anteromedial disc displacement was observed in 29 discs, and anterolateral direction in 6 discs. Among 35 rotational displacement, 5 biconcave discs and 21 deformed discs were observed. CONCLUSION: Rotational and sideways displacement of TMJ discs were found to be common and an important aspect of internal derangement. This study also suggests that sagittal and coronal images of the TMJ have complementary abilities for an assessment of joint abnormality.