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Volume 57, Issue 1
Displaying 1-16 of 16 articles from this issue
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Satoshi Sasaki, Masae Goseki1990 Volume 57 Issue 1 Pages 1-11
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (2083K) -
-2 Chromosome Analysis of TwinsKenji Hashimoto, Shigetoshi Shioda, Hidemi Yoshimasu, Kohyoh Nakamura, ...1990 Volume 57 Issue 1 Pages 12-15
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDevelopment of DNA diagnosis on the monocular level for patients with cleft lip and/or palate may be expected in the near future. The necessary condition for this is to confirm the heredity, elucidate the mode of inheritance and decide on the regional mapping etc. The authors tried a chromosome analysis on a pair of monozygotic twins with cleft lip and palate by using high-resolution banding techniques (about 700 bands) . However, chromosome aberration was not confirmed. Therefore, the relation between this congenital anomaly and the chromosome aberration could not be confirmed. In this paper the authors discussed about this problem.View full abstractDownload PDF (568K) -
Tatsutomi Watanabe1990 Volume 57 Issue 1 Pages 16-31
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSBilateral balanced occlusion is believed to be one of the ideal types of occlusion for complete denture. However, there are still many obscure items about its function during mastication, considering that the occlusion is adjusted on the articulators under the no-food condition. To analyze this problem, the author has already developed a six-channel telemetry system for recording the masticatory forces during mastication. This study was performed with this system. The purpose of this study was to analyze the occlusal force of the lower artificial posteriors in the cases of complete denture with bilateral balanced occlusion during mastication.
In this report, the masticatory force and impulse in three complete denture wearers were measured and studied.
The results were as follows
1. On the working side, the lower artificial first molars showed the strongest force among the same side artificial posteriors, as previously reported.
2. On the balancing side, the lower artificial second premolars showed the strongest force and impulse, followed in order by the lower artificial first molars and the second molars.
3. It is suggested that the lower artificial second premolar of the balancing side would contribute to the denture stability during mastication.View full abstractDownload PDF (4571K) -
Toshimoto Tengan1990 Volume 57 Issue 1 Pages 32-57
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe present investigation is carried out to study the histogenesis and the three-dimensional interrelationship of the mandibular condyle, mandibular body, angular cartilage and Meckel's cartilage in the C57BL mouse fetuses.
The frontal serial sections obtained at 13 to 18 days of gestation (plug day=0) were used for the histological observation and the digitized area data from the tracings of each specimen were provided for the computer-aided reconstruction.
The results were as follows:
1. The primordium of the condylar cartilage appeared in the area of the supero-lateral site of the primordium of the mandibular body at 14.5 days of gestation.
2. After 14.5 days of gestation, the mandibular body developed, covering the primordium of the condylar cartilage, but its developmental process was slightly different between the medial and the lateral site.
3. The condylar cartilage at 16 days of gestation was comparable to carrot-shape.
4. Endochondral bone formation was demonstrated at the most medial portion of the condylar cartilage at 18 days of gestation.View full abstractDownload PDF (23277K) -
Hiroaki Nagai1990 Volume 57 Issue 1 Pages 58-69
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSMinor differences in chemical composition of permanent and deciduous teeth have been suggested, however, clear data on the difference in organic composition have not yet been established. In the present study, organic dentin matrix components of bovine permanent and deciduous teeth were investigated.
Bovine permanent and deciduous dentins were obtained from respective incisors and divided into crown and root. They were crushed into powder and extracted with 4M guanidine-HC1 (G-extract), and then with 0.5M EDTA, 4M guanidine-HC1 (E-extract) . E- e xtracts from permanent crown and root dentin and also deciduous crown and root dentin were separately applied to DEAE-cellulose column and each peak was examined precisely by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) . A quantitative difference in organic matrix composition was recognized between permanent and deciduous dentin. Furthermore, a non-collagenous protein fraction, which existed in permanent teeth but not in deciduous ones, was discovered. This protein was purified as a single band in SDS-PAGE, which demonstrated an apparent molecular weight of approximately 30 Kd. Its amino acid composition was analyzed and the nature of this protein was discussed.View full abstractDownload PDF (6722K) -
Akihide Negishi1990 Volume 57 Issue 1 Pages 70-82
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe purpose of this paper is to produce monoclonal antibodies which recognize hemidesmosomes and to analyze the differences in the expression between in normal epithelium and squamous cell carcinoma.
Cultured squamous carcinoma cells derived from oral mucosa were immunized to mice and one monoclonal antibody named 8A12 was obtained. The antibody 8A12 was found immunoelectron microscopically to react with the extracellular constituent of hemidesmosomes with which the basal cells adhere to the matrix in normal human tongue epithelium. In cases of oral squamous cell carcinoma, positive immunostaining by 8Al2 was observed in the actively-proliferating undifferentiated cancer cells. These cells showed a positive reaction over the entire cytoplasm. Because of the expression of the 8Al2-epitope in cultured cancer cells, the hemidesmosomal component which is distributed on the surface of the normal cells is thought to accumulate intracellularly.
These results suggest that the antibody 8Al2 is useful for the diagnosis of squamous cell carcinoma and for the identification of the degree of differentiation. Moreover, abnormal transportation of the hemidesmosomal component is suggested to be related to carcinogenesis and metastasis.View full abstractDownload PDF (8045K) -
Shumpei Yamada1990 Volume 57 Issue 1 Pages 83-105
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSTo analyze the role of c-and N-myc on the craniofacial development during the midgestation of mouse embryo, the tempospatial expression in the mandible and the tooth germ was examined by in situ hybridization.
In the mandible, c-myc RNA was strongly expressed in the mesenchymal condensation surrounding the ossification center in which a high-level expression of osteopontin was detected with the basal-level expression of c-myc in the corresponding area. In tooth germs, the strong expression of c-myc was detected uniformly in the epithelia of bud stage and then gradually localized in the inner enamel epithelia from cap to bell stages. In contrast, the expression of N-myc was weakly detected in the undifferentiated mesenchymal cells of the dental papilla but was not detected in the regions where c-myc was highly expressed.
To study the correlation of myc expression and growth activity, the incorporation of BrdU was examined immunohistochemically. The results revealed that levels of BrdU incorporation were similar between the regions where c-myc was highly expressed and the regions where basal-levels of c- and N-myc expression were detected, suggesting that levels of myc expression are not necessarily correlated to the growth activity. These results indicated that c- and N-myc genes are differentially expressed and further raise the possibility that c- and N-myc may play a major role in differentiation rather than proliferation in the early stage of these organogenesis.View full abstractDownload PDF (19983K) -
-Especially on Gene Expression of Differentiation Markers-Akira Nifuji1990 Volume 57 Issue 1 Pages 106-115
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSRegulation of α2 (I) collagen and osteonectin/SPARC gene expressions in mouse osteoblastic MC3T3-E1 cells by TGF-β1 was studied. TGF-β1 regulated those differentiation markers of osteoblast phenotypes, although the effects were inconsistent depending on serum concentrations. Exposure of MC3T3-El cells to TGF-β1 in low serum culture caused stimulation of α2 (I) collagen and osteonectin expressions but no stimulation in high serum culture. These inconsistent responses may be due to the presence of some component (s) in serum. bFGF also suppressed stimulation by TGF-β1 on α2 (I) collagen and osteonectin expressions. Serum factors as well as locally derived growth factors may interact with TGF-β1 and modulate the actions of TGF-.β1 in osteoblastic cells. The present result explains the complexity of TGF-β1 actions on bone cells in vitro and also suggests that the actions on bone formation are modified by other factors in vivo.View full abstractDownload PDF (7584K) -
Mariko Hashimoto1990 Volume 57 Issue 1 Pages 116-145
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe purpose of this study was to observe the regeneration of the periodontal tissue using porous hydroxyapatite granules in experimental periodontal lesions. The upper lateral incisors of three Macaca fuscatae were extracted. After a 12-week recovery period, three wall infrabony defects were surgically prepared on the distal surface of the central insisors. In order to accumulate the plaque and cause inflammation, a wire with dental floss was placed inside the defects for a period of four weeks and then removed. Flap operations were performed and porous hydroxyapatite granules were placed into the defects.
Twelve weeks after surgery, the samples were taken out and fixed in glutaraldehyde solution. They were embedded in polyester resin and undecalcified sections were prepared. The specimens were stained with toluidine blue and observed under light microscope.
Results: 1) The implanted area was divided into three distinctive zones. The first zone was located distally and occupied two-thirds of the total area. A large quantity of osseous tissue was detected. The second zone was situated near the root and presented only a small quantity of osseous tissue; Fibrous connective tissue predominated in the third zone adjacent to the root. 2) Bone apposition and resorption caused by physiologic mobility and movement of the teeth were observed.
These results suggest that the elimination of the functional forces is advisable during the healing period whenever hydroxyapatite granules are placed into the periodontal defect.View full abstractDownload PDF (17305K) -
Mikio Ito1990 Volume 57 Issue 1 Pages 146-164
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe mechanical properties of the Akers type clasp, bar and frame made by the newly developed Ti-20Cr-0.2Si alloy were studied in order to obtain the indices for designing the cast partial denture base.
In the case of the clasp, the bending strength of the Ti-20Cr-0.2Si alloy and pure Ti was lower than that of the Co-Cr alloy. The Ti-20Cr-0.2Si alloy and pure Ti may have the same retentive force as the gold type IV alloy because its bending behavior was similar to that of the gold alloy. In the cyclic bending test, the permanent deflection of the Ti-20Cr-0.2Si alloy was lower than that of the pure Ti and Co-Cr alloy. It had almost the same value as that of the gold alloy. Considering the permanent deflection and fracture, it is preferable that the undercut of the abutment tooth for the Ti-20Cr-0.2Si alloy clasp is 0.50mm or less.
The Ti-20Cr-0.2Si alloy bars and frame showed the same bending behavior and strain distribution as the gold alloy. In the case of the Ti-20Cr-0.2Si alloy bar thickened about 30%, the strain was decreased and close to that of the Co-Cr alloy. It was suggested that the Ti-20Cr-0.2Si alloy bar or frame should be designed like the gold alloy.View full abstractDownload PDF (7762K) -
Hideaki Koibuchi1990 Volume 57 Issue 1 Pages 165-186
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSwere investigated on 6 subjects.
The metal castings of 100-μm thickness were fabricated to make experimental premature contacts on each of 4 mandibular posterior teeth (from the first premolar to the second molar on the preferable masticatory side) .
The EMG activity of the masseter, anterior and posterior temporal muscles during maximum clenching and gum chewing as well as the mandibular movement during gum chewing were evaluated.
The experimental premature contacts reduced the muscle activity, especially on the contralateral side during maximum clenching.
As the premature contact was moved more posteriorly, the following results were observed.
1. The activity of the posterior temporal muscle was decreased on the ipsilateral side while it increased on the contralateral side during maximum clenching in many subjects.
2. The duration of the occlusing phase during the ipsilateral chewing was shortened in many subjects.
3. During ipsilateral chewing, a larger muscle activity was produced during the closing phase and the muscle activity produced during the occlusing phase was the least on the first molar.
4. In any chewing side, the closing and opening paths tended to go toward the chewing side.View full abstractDownload PDF (6709K) -
Takafumi Yamada1990 Volume 57 Issue 1 Pages 187-200
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSTo examine the relationship between the oral leukoplakia and cancer, an immunohistochemical study of the EGF-receptor was performed by the avidin-biotin peroxidase-complex method and silver enhancement with anti-human EGF-receptor antibody (Bio-yeda) .
Totally 61 cases of leukoplakias without relation to cancer, 20 cases of leukoplakias with relation to cancer and 31 cases of squamous cell carcinomas were examined.
Seventy percent of leukoplakias and 55% of cancer cases were positive for the EGF-receptor. The proportion of the EGF-receptor-positive cells in the leukoplakia cases was slightly decreased in proportion to the degree of the epithelial dysplasia. The proportion of the EGF-receptorpositive cells in the poorly differentiated type cancer cases (3) was fewer than that in the differentiated type cancer cases (31%) . In the leukoplakia related to cancer, the leukoplakia and cancer of the same patient did not always show the same pattern of EGF-receptor.View full abstractDownload PDF (12982K) -
Ken Tomizuka1990 Volume 57 Issue 1 Pages 201-226
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSThe purpose of this study was to investigate the possibility of applying hydroxyapatite ceramics as endodontic-endosseous implants.
The upper medial incisors of 3 monkeys (Macaca fuscatae) were used. To prepare the implant cavity, the teeth were extracted and drilled from the apex by steel burs under watercooling. Then, dense hydroxyapatite implants, 10mm in length, 2mm in maximum diameter and 1/20 tapered, were inserted into the cavity to have the implant project 3. `4mm above the apex. When the teeth with the implants were replanted, the bone around the apex was removed. The teeth were splinted to the neighbouring teeth for 1 month. Five months after the operation, the specimens were taken out and fixed by 10% formalin alcohol. They were embedded in polyester resin and undecalcified sections were prepared. The sections were stained with toluidine blue and observed under light microscope.
Results: 1) At 5 months, no ankylosis between the tooth and the surrounding alveolar bone was observed. 2) There was newly formed hard tissue which extended from the cementum, on the surface of the implant. 3) Fiber bundles were observed around the implants which connected the newly formed hard tissue to the surrounding bone tissue. The results suggest that the application of hydroxyapatite ceramics as an endodontic-endosseous implant is effective.View full abstractDownload PDF (17448K) -
Hiroko Mega, Norihiko Okada, Satoshi Ochiai, Toshihiko Fukawa, Yukou I ...1990 Volume 57 Issue 1 Pages 227-238
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSOne family of familial gingival fibromatosis was presented. Case 1 is an 11 years old girl. Gingival fibromatosis was noted by delayed eruption of permanent teeth. Fibromatosis was seen in whole gingiva and lower 1/2 to 1/3 of the tooth crowns was covered. Gingivectomy was performed. Case 2 was 42 years old man, who was father of case 1. Firstly gingival swelling was noted at the age of 10 years. He had operations of gingivectomy at the age of 28 years. It recurred and fibromatosis was seen in whole gingiva and lower 1/2 to 1/3 of the tooth crowns was covered. Cytogenetically no abnormality was seen in the chromosomes of both cases. Reported cases of familial and non-familial gingival fibromatosis in Japan were reviewed.View full abstractDownload PDF (9682K) -
1990 Volume 57 Issue 1 Pages 239-243
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (3037K) -
1990 Volume 57 Issue 1 Pages 244-261
Published: 1990
Released on J-STAGE: October 27, 2010
JOURNAL FREE ACCESSDownload PDF (4834K)
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