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Volume 37 (1997)
- Issue 4 Pages 275-
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- Issue 2Supplement Pag･･･
- Issue 2 Pages 125-
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Volume 37, Issue 1
Displaying 1-13 of 13 articles from this issue
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[in Japanese]1997 Volume 37 Issue 1 Pages 1-2
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
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Takehito SASAKI1997 Volume 37 Issue 1 Pages 3-14
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSRadiation carcinogenesis has been thought as a stochastic phenomenon without any threshold dose of radiation. Although this concept is very important, the presence or absence of a threshold dose in the dose-response relationship is difficult to directly confirm. This review discusses the implication of recent analysis of cancer mortality among atomic bomb survivors and multistep genomic changes involved in human carcinogenesis in relation to the radiation carcinogenesis at low doses. The remarkable similarity in the both shape and magnitude of the dose responses curve is seen between mutational cellular events and cancer incidence among atomic bomb survivors. In view of the increasing evidence for radiobiological mechanisms of radiation carcinogenesis including activation of oncogenes and inactivation of tumor suppressor genes and for analysis in the models of dose-response relationship, it seems likely that radiation is responsible for one mutational event in multistep genomic changes in carcinogenesis.View full abstractDownload PDF (1760K) -
Nishio MASAMICHI1997 Volume 37 Issue 1 Pages 15-22
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSOf the 195 primary cases with squamous cell carcinoma of the tongue treated at National Sapporo Hospital between 1978 and 1990 were reviewed, 152 cases were treated with interstitial needle implant with or without external beam irradiation and 43 cases were treated by operation. The local control rate by needle implant for the primary tongue lesions was 88% and the cause-specific 5-year survival rate was 82%. QOL is a serious problem for the cancer patient, but the most important problem is the reasonable quality of treatment provided from the medical therapist. From this point of view, the interstitial implant for early cancer of mobile tongue is the best treatment in preservation of function and form, in the medical cost and treatment period. From the viewpoint of scientific sociology, we will be discussing the usefulness of radiotherapy and comparison of the structure of radiation oncology in Japan and the United States. Specialists must notify their fellow-physicians in related departments about the advantage of radiation therapy, and the well-balanced cancer therapy is expected to be useful.View full abstractDownload PDF (6798K) -
Tsukasa SANO, Mika YAMAMOTO, Takayoshi YAMAGA, Koji TAKAHASHI, Saeko M ...1997 Volume 37 Issue 1 Pages 23-28
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSCrepitus is an important sign for diagnosis of arthrosis of the temporomandibular joint (TMJ). The presence of crepitus can be evaluated by the listening test previously proposed by our group. However, TMJ can be diagnosed by MR imaging showing the disc position and related findings including bony changes and joint effusion. This study investigated the relationship between the presence of crepitus and pathology of the joint. Fourteen joints with crepitus diagnosed by the listening test were examined in this study. TMJ was categorized into four types based on findings on double spin echo MR images. The results were as follows: Of fourteen joints with crepitus, five (36%) were showed as normal superior disc position. The remaining 9 joints (64%) were diagnosed with disc displacement, of which, 6 showed reduction, one was without reduction and 2 without reduction were associated with arthrosis. Statistical analysis using the data obtained here and other data showed that the joints with crepitus tended to show disk displacement. There was no significant difference between the degree of certainty about the presence of the crepitus and the distribution of joint pathology. Joint effusion was observed only in the joints with displacement. These results indicated that TMJ with crepitus is associated with varied joint pathology.View full abstractDownload PDF (4191K) -
Yosuke SUZUKI, Akira YOSHIDA, Nobue MATSUMOTO1997 Volume 37 Issue 1 Pages 29-34
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSTo reduce quantum noise and improve image quality, a multi-film packet was produced experimentally for intra-oral radiography. The images on seven-films were averaged by digital addition using a computer with a CCD camera and microscope. In this digital addition, an image processing software commercially available was used. The signal-tonoise ratio (SNR) was measured to evaluate the reduction of quantum noise and the improvement of image quality. SNR value of the average image of seven films was approximately 2 times larger than that of the conventional single film image. Even if conventional 2 packing film was used, SNR value improved 30% by digital addition of 2 films. In a close inspection of small area such as apex of tooth, the averaging of images was effective to observe the shape of root canal because of the reduction of the quantum noise. Further research is needed to simplify the digital adding procedure in clinical use.View full abstractDownload PDF (2283K) -
Part1: Measurements of the Intercondylar DistanceManabu SHIMOMURA, Takaharu KUDOH, Shinichi KAWAGUCHI, Akira TAKAHASHI, ...1997 Volume 37 Issue 1 Pages 35-40
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSTo obtain a clear image of the temporomandibular joint (TMJ) on a rotational panoramic radiograph, the mandibular condyle should be in the image layer of panoramic equipment. The intercondylar distance in Japanese subjects was measured to identify the position of TMJ relative to the image layer. Submento-vertex radiographs from 848 patients suspected of having temporomandibular disorders (669 females; between 8 and 82 years, 179 males; between 9 and 79 years) were studied. The distance between the center points on long axes of the bilateral condyles was measured as an intercondylar distance. The measurement value was corrected by a magnification factor calculated from the inter-earplug distance on a radiograph and actual distance. The intercondylar distance showed normal distribution, and its mean value was found to be constant in the subjects with 20 years old or older, 101.1±4.7mm in femaless and 106.1±5.3mm in males. To derive a clear image of TMJ from the rotational panoramic radiography, the effective image layer distance between left and right TMJs should be adjustable to several values, for example, 101 and 106mm.View full abstractDownload PDF (2253K) -
Part 2: A Study of Horizontal Optimum Angle of X-ray Beam to Mandibular CondyleToru TAKEUCHI, Akira TAKAHASHI, Chieko SUGAWARA, Manabu SHIMOMURA, Nao ...1997 Volume 37 Issue 1 Pages 41-48
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSThe horizontal angle of x-ray beam projection to obtain an optimum anterior-oblique view of the mandibular condyle on a panoramic radiogram with least superimposition of the cranial base structures was examined. Eleven left temporomandibular joints from 11 dried human skulls were studied. Thirteen images were obtained for each joint, projected from 8° posterior to 52° anterior in 5° steps. The possible structures superimposing the condyle were the eminence from infratemporal crest to sphenoid spine, the eminence from articular tubercle to sphenoid spine, post glenoid process, anterior wall of the external auditory meatus, and mastoid process. None of the structures except mastoid process caused any problem in tracing the contour of the condyle. The part of the condyle with superimposition of the mastoid process was difficult to interpret, and extent of the part spread gradually as the projection angle increased. Nine out of 11 (82%) condyles were not superimposed with the mastoid process when a 30° anterior projection was adopted. This was considered to be the most suitable angle to obtain an anterior-oblique aspect of the mandibular condyle keeping good visibility.View full abstractDownload PDF (5789K) -
Yoshihiko HAYAKAWA, Norio KOBAYASHI, Yuji KOUSUGE, Hisao FUJIMORI, Kin ...1997 Volume 37 Issue 1 Pages 49-55
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
JOURNAL FREE ACCESSObjectives: Output intensities (air-absorbed doses in air: Gy) were measured at the cone tip using six dental x-ray generators. Methods: The type 660 ionizing dosimeter (Victoreen, Inc.) was used. The flat probe, type 660-3, was set at the cone tip of each dental x-ray generator. Measurements at three exposure times, of approx. 0.3, 0.6 and 1.0s were repeated five times. The exposure time versus air-absorbed dose relationship and the air-absorbed dose rate, were obtained for each generator. The number of exposure time settings required to give an air-absorbed dose of less than 2.00mGy at the cone tip was evaluated for each generator. Results: Outputs of two generators which were furnished with a short cone (20cm focal spot to cone tip distance) were 3.38 and 6.95mGy/sec at 60kV, and 4.67 and 9.82mGy/sec at 70kV. Outputs of four generators with a long cone (30-35cm) were distributed in the range of either 1.50-1.68mGy/sec or 3.06-3.57mGy/sec at 60kV, and either 1.95-2.29 or 4.06-4.73mGy/sec at 70kV, respectively. The calculated outputs at 10cm beyond the cone tip with two generators with a short cone were included in this range. The number of exposure time settings to give absorbed doses of less than 2.00mGy was in the range of 43 to 70% for five generators. One of the six generators had the low output rate. Conclusion: This experiment using six dental generators clarified that there were two kinds of generators which were distinguished by the x-ray output intensity. Some dental x-ray generators had outputs in the range of approximately 1.5-1.7mGy/sec at 60kV, and approx. 2.0-2.3mGy/sec at 70kV at the tip of the long cone. Outputs with other generators were approximately twice of these values. These findings are useful to evaluate the doses absorbed by the patient's skin surface, which is the maximum for the patient at the intraoral radiographic examination.View full abstractDownload PDF (876K) -
Naoki MAEDA, Michiko KUBO, Hidehiko HOSOKI1997 Volume 37 Issue 1 Pages 56-57
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
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[in Japanese]1997 Volume 37 Issue 1 Pages 58-73
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
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1997 Volume 37 Issue 1 Pages 74-86
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
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1997 Volume 37 Issue 1 Pages 87-106
Published: June 05, 1997
Released on J-STAGE: September 05, 2011
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1997 Volume 37 Issue 1 Pages e1
Published: 1997
Released on J-STAGE: September 05, 2011
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