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Volume 17 (1977)
- Issue 3 Pages 177-
- Issue 2 Pages 101-
- Issue 1 Pages 1-
Volume 17, Issue 1
Displaying 1-12 of 12 articles from this issue
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Takuji KIHARA1977 Volume 17 Issue 1 Pages 1-17
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSA survey on questionnaire was made of the frequency of dental radiography by the site of exposure at Osaka Dental University Hospital and 700 dental clinics in Osaka.The data obtained were used with those for dental radiography frequency in Japan, and phantom human dosimetry data, to estimate the average critical organ dose per film, and the critical organ doses per capita per year from dental radiography in Japan.
The results obtained were as follows:
1.Doses to the lens and thyroid gland varied with the skin surface beam size. Lens and thyroid gland doses using 6.5, 8 and 10 cm field sizes during full mouth radiography with 14 films were 264, 1240, 1770 mrad and 342, 1190, 1810 mrad, respectively.
The highest doses to the lens were incurred by upper cuspids and upper bicuspids examinations;the highest doses to the thyroid, by lower molars examinations.
2.Total dental X-ray examinations increased abruptly after 1962 and there were 2.9 billion of the“usual”type in 1970.This was the equivalent of 0.3 X-ray examinations per person that year for Japan.
3.The average doses per dental radiography exposure were 80.1 mrad to the lens, 2.9 mrad to the pituitary gland, 153 mrad to the thyroid gland and 955 mrad to the skin.
4.The average doses per capita in 1970 were 22.1 mrad to the lens;0.80 mrad to the pituitary gland;42.2 mrad to the thyroid gland and 263 mrad to the skin.View full abstractDownload PDF (2796K) -
Shinichi NISHIYAMA1977 Volume 17 Issue 1 Pages 18-31
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSIt is generally agreed that the radiographic patterns of periapical lesions, in its early stage, are difficult to detect.The radiographic representability in such pathological patterns varies in accordance with the structural characterics of body sites.This is mainly due to the fact that undesirable scatter rays from adjacent tissues considerably affect the image quality, and lower the image representability.It is also well established that the smaller the radiation field, the less the radiation scatter, contributing to impoved image quality.
The present author compared the image effect between a conventional“Open-end Cone”and a“Narrow-collimation Tube”with the view to decrease scatter ray. Exposures were made using“Open-end Cone”and“Narrow-collimation Tube”, of a molar region specimen of mandible, and examined the radiograms for the quality of detail in the areas of interest.Image variation was also examined when different materials were inserted inside the bone defects.
The clinical contribution of“Narrow-collimation Tube”on the radiographic image representability of periapical bone defects was confirmed based on the above experimental results, the effect on image enhancement was also studied in four clinical trials.
The results were as follows;
1.The radiographic image representability of artificial bone defects in the periapical region of the manbible specimen differs according tothe amount of destruction of bone structures.Further, the radiographic image represntability varies, even when the bone defects are o the same size, in accordance with their contents of different materials,
2.“Narrow-collimation Tube”compared to the conventional“Open-end Cone”provides us with clear and contrasted images of bone defects.Even using this new“Narrow-collimation Tube”device it is impossible to detect cancellous bone defects more than 4mm in diameter unless they also extends into the cortical bone.
3.With“Narrow-collimation Tube”, the four clinical radiograms provides us with better image representability of periapical lesions than the conventional“Open-end Cone”.View full abstractDownload PDF (4374K) -
Takashi IWANO, Yoshiyuki KANAI, Katumi NIWA, Thikara AKAMA1977 Volume 17 Issue 1 Pages 32-35
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSCieszynskis'bisecting-angle technic contains some presumptive factor, which is plane of tooth, incline angle film and bisecting plane.Therfore retake chance with projectionmiss is often, and exact retention of film in oral cavity is comparatively difficult too.
In a paper entitled“The measuring apparatus of the direction of central-ray in in-traoral roentgenography”Shimano and others divised method make clear to sight presump-tive factor in bisecting-angle technic.
We make as a test filmhoder, which is connected with the measuring apparatus of the direction of central-ray, and state clearly direction of central-ray and make sure fixation of film in oral cavity, and attempt reduce to a minimum retake chance and exposure dose of X-ray.View full abstractDownload PDF (395K) -
Naoyuki YAMADA, Seiichi TOYOSHIMA, Toshio KANETA, Hideto OIKAWA, Kazuo ...1977 Volume 17 Issue 1 Pages 36-43
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSThe rare four cases showing intrapulpal calcifications and 735 cases (19837 teeth) for the student's treatment were studied radiographically by full-mouth X-rays.
1.The intrapulpal calcification of the total teeth of a patient may be related to some general systemic diseases.
2.It is difficult in radiographical survey of 735 cases to recognize the intrapulpal calcification increase in association with aging.
3.The intrapulpal calcification occur in 1.88% of all teeth of 735 cases.
4.Occurrence in female to male is in ratio of 1.6 times.
5.The intrapulpal calcifications are seen most frequently in molar and canine teeth.
Some possible diseases showing intrapulpal calcifications in dental full-mouth X-rays are discussed.View full abstractDownload PDF (2656K) -
Masahiro EHARA, Kiyoshi UCHINOUMI, Yonoshin KOSEKI, Kazuhiko IMAI, Ken ...1977 Volume 17 Issue 1 Pages 44-51
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSAn analysis was made of the roentgenographic appearance of 24 acceptable cases, in which one instance was the bilateral condition, of the so-called developmental bone defect from 9718 panoramic and routine dental roentgenograms.
The results obtained were as follows:
1.All of these bone defects were located beneath the mandibular canal and between the angle of the mandible and the molar tooth.
2.The age range of the 24 patients was 29 to 77 years, with a peak incidence in the fifth decade of life.It occured more frequently in male than in female and in the ratio of 7 male to 1 female, and also the frequency of occurrence was 1/370 in a person above twenty-one years of age.
3.This lesion is resembled to the cystic lesion in roentgenographic apperrance.But it is characteristic that radiopaque rim of the lesion continues to the cortex of the border of mandible on the direction of the X-ray projection.
On the roentgenograms, this appearance can be distinguished between the so-called developmental bone defect and other bone defect of the central lesion of the bone.And also, sialograms of the submandibular gland may be suggested that this lesion has relations with the submandibular salivary gland on it's location.View full abstractDownload PDF (5760K) -
Takashi MARUYAMA, Tadashi HASHIZUME, Kanae NISHIZAWA, Shoichi ANDO, Ko ...1977 Volume 17 Issue 1 Pages 52-63
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSThe genetically significant dose (GSD), per Caput mean bone-marrow dose (CMD) and leukemia significant dose (LSD) from dental intra-oral radiography have been estimated on the basis of a nation wide survey.The survey was carried out for the collection of the over-all numbers of dental radiographic procedures in age-group and technical factors on the patients from a known fraction of dental hospital and clinics.The annual number of intraoral radiographs was estimated to be 9×107.
The absorbed dose in the eyes, thyroids and the gonads was determined with ionization chambers, using a Rando-phantom.The bone marrow doses were measured with thermoluminescent dosimeters placed in various parts of skeleton in the Rando-phantom.The population doses such as GSD were calculated with a Tosbac 3400 computer, using the technical factors on the patients selected in the nation wide survey and the absorbed dose in the critical organs.
The resultant GSD, CMD and LSD was 0.013 mrads per person per year, 3.7 mrads per year and 3.4 mrads per person per year, respectively.The collective dose for the eyes and thyroids was 3.2×105 and 1.0×105, respectively.View full abstractDownload PDF (1543K) -
Kenji KAWAHARA, Noriko YAMAMOTO, Miharu NISHIKIORI, Yoshishige FUJIKI, ...1977 Volume 17 Issue 1 Pages 64-69
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSHaving encountered a rare case of a21-year-old male having three supernumerary teeth, the so-called paramolar or fourth molar in the upper and lower molar regions, we conducted roentgenological and morphological observations of the case and presented here its findings.Morphologically, the case showed the fusion of the fourth molar of the right mandible and impacted along with the lower right third molar, both of which were extracted. Each crown of the fused teeth showed the resemblance to upper premolar in shape.View full abstractDownload PDF (1629K) -
Kinya KUROYANAGI, Shigeru MATSUSHITA, Yuuki MASAOKA, Tadaaki MIYA, Sho ...1977 Volume 17 Issue 1 Pages 70-73
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSTwin nasopalatine cyst is quite rare and is seldom reported in the literature.
An understanding of the nasopalatine cyst and of the etiology is dependent upon at least a condensed review of the embryologic development of associated nasal and oral structures.
Then, it should be noted here that the terms incisive canal and nasopalatine duct are not synonymous.The incisive canal is a passageway, through the bone of the hard plate, connecting the oral and nasal cavities.An epithelium-lined tube, or remnants thereof, may be found within the incisive canal;this epithelial structure is the nasopalatine ducts.These passageways are formed-one on each side of the nasal septum.
The present case might be derived from two ducts.View full abstractDownload PDF (932K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese]1977 Volume 17 Issue 1 Pages 74-78
Published: 1977
Released on J-STAGE: October 21, 2010
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1977 Volume 17 Issue 1 Pages 83-95
Published: 1977
Released on J-STAGE: October 21, 2010
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1977 Volume 17 Issue 1 Pages 96
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSDownload PDF (153K) -
1977 Volume 17 Issue 1 Pages 97
Published: 1977
Released on J-STAGE: October 21, 2010
JOURNAL FREE ACCESSDownload PDF (98K)
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