Japanese Journal of Oral Biology
Print ISSN : 0385-0137
Volume 36, Issue 5
Displaying 1-11 of 11 articles from this issue
  • Yuji Ehara, Fumihiko Suwa
    1994 Volume 36 Issue 5 Pages 471-485
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    Sequential changes in the microvasculature and new bone formation, especially in the open pores on the interface of polycrystal ceramic implants were investigated using microcorrosion cast-bone specimens under a scanning electron microscope. The implant materials consisted of a cylinder with a core of single-crystal alumina and an outer pored polycrystal layer (Bioceram Porous Implant 42 POSSS® and 42 PX10®). Implantations were performed in extraction sockets of mandibular premolars and molars in adult Japanese monkeys. Five days after implantation, no primary bone trabeculae were observed. However, new sinusoidal capillaries had sprouted from pre-existing blood vessels. At one week, new bone and capillaries had not yet passed through pore openings, but active proliferation of sinusoids and new bone formation were seen. At two weeks, new capillaries began to enter the pores and form glomeruli, while bone trabeculae only invaded large-caliber pores. At three weeks, mature capillaries and tiny needle-like bone trabeculae were observed in the pores. From four to nine weeks, almost all of the pores were filled with woven bone, and a cylindrical alveolus was formed outside the polycrystal interface. These results suggest that more tha nine weeks may be required for the invasion of new bone and capillaries from the outer polycrystal interface into the pores of the implant. The capillaries in the pore labyrinth showed, irregular growth characteristics.
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  • Jun-ichi Odashima
    1994 Volume 36 Issue 5 Pages 486-497
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    The present study was performed to investigate the effect of lidocaine on memory in mice using a novel multiple maze apparatus. After a 15 h fast, male ddY mice were placed in a multiple maze apparatus (water and food were placed at the entrance and exit of the maze, respectively) for 90 min (9: 00-10: 30a.m.) and allowed to learn the maze. Lidocaine (20-80mg/kg, i. p.) was injected either immediately after learning, 6 h after learning or 15 min before the trial, which was performed 24 h after learning. In the trial, the mouse was placed at the entrance, and the number of errors and the time (running time: RT) until the mouse reached the exit were counted. Administration of lidocaine immediately after learning influenced performance in the maze task: lidocaine 40mg/kg decreased both the number of errors and RT, whereas lidocaine 80mg/kg (convulsant dose) caused amnesia. In contrast, when lidocaine was injected 6 h after learning or 15 min before the trial, it had no effect on performance. A similar modification of memory was observed using picrotoxin, a GABA antagonist: i. e. picrotoxin 1mg/kg decreased both the number of errors and RT, whereas picrotoxin 4mg/kg (convulsant dose) caused amnesia. Pretreatment with diazepam 5mg/kg blocked both the memory-enhancing effect and memory-impairing effect of lidocaine. These findings suggest that lidocaine below the convulsant dose enhances memory consolidation through central nervous system excitation by blocking inhibitory synapses, and that lidocaine-induced convulsion impairs memory consolidation.
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  • Mitsuhiro Noda, Masatsugu Yamamura, Ichio Takase, Shojiro Asai, Yasuka ...
    1994 Volume 36 Issue 5 Pages 498-509
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    The STAPHYOGRAM kit system was compared with Kloos' simplified method for identifying coagulase-positive staphylococci isolated from human oral cavities. In addition, we determined whether or not the code numbers in the kit, which purportedly represent biochemical characteristics, correlated with the biological tests.
    Gram-positive cocci isolated from oral cavities were first examined for catalase and coagulase activities, DNase production and mannitol fermentation species of the isolates that were positive for these four tests was subsequently confirmed using the STAPHYOGRAM kit.
    Of the 34 isolates that were assumed to be strains of Staphylococcus aureus by the first four tests, 31 (91%) were assigned 13 code numbers and identified as S. aureus by the STAPHYOGRAM kit. Code numbers 723346 and 723347 were each represented by 14 strains (45% of the total). The remaining 11 code numbers accounted for less than 9% of the strains. The 13 code numbers were not related to the production of pigment or hemolysin.
    However, code numbers 723346 and 723347 were thought to be related to the coagulase type VII since 67 to 80% of the strains with these numbers showed this coagulase type.
    These results indicate that the STAPHYOGRAM kit system is useful in the identification and biochemical characterization of S. aureus in oral cavities.
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  • Masaaki Okamoto, Naoki Hasegawa, Nobuko Maeda, Nobukazu Sugahara, Hiro ...
    1994 Volume 36 Issue 5 Pages 510-519
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    A new bisphosphonate, disodium dihydrogen (cycloheptylamino) methylene-1, 1-bisphosphonate (YM175) i s a potent inhibitor of bone resorption. The purpose of this study was to evaluate the effect of bisphosphonates, including YM175, on alveolar bone loss in experimental periodo ntitis using Golden hamsters. Hamsters were fed powdered high-carbohydrate diet (30% sucrose) to induce periodontal disease, andr eceived subcutaneous injections of either saline, YM175 (0.001-0.3mg/kg) or 1-hydroxyethylidene-1, 1-bisphosph onate (HEBP, 1-10mg/kg), which has been previously shown to regulate bone metabolism. Thef ollowing results were obtained: 1. In the control group (saline), the number of osteoclasts on the mesial side of the alveolar bone of the lower first molar was increased on the s econd week of the experiment.H owever, in the experimental group that was administered YM175, the number of osteoblasts on the distal side of the alveolar bone was increased on the first week, and no increase in the number of osteoclasts was observed, even on the second week. 2. Alveolar bone loss at the lower first molar, decreased with the consecutive administration of bisphosphonates. 3. The inhibitory effect of HEBP on alveolar bone loss was weaker than that of YM175. 4. Weight loss of mandibular bone was inhibited by the ad ministration ofYM175. 5. The levels of plasma calcium, inorganic phosphate and alkaline phosphatase were not affected b ythe administration of YM175.
    In conclusion, YM175 significantly inhibited alveolar bone resorption in experimental periodontitis, andmay, therefore, offer a new approach to the treatment of periodontal disease.
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  • Masaru Sato, Hironori Tsuchiya, Ryozo Yamaguchi, Uichi Itoh, Ichio Tak ...
    1994 Volume 36 Issue 5 Pages 520-525
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    The coaggregation of methicillin-sensitive and-resistant Staphylococcus aureus (MSSA and MRSA) with different oral microorganisms, and their aggregation mediated by saliva, were studied. Both types of staphylococci showed similar coaggregation properties. All of the staphylococci, except for one MRSA strain, strongly coaggregated with Fusobacterium nucleatum. Several strains also moderately coaggregated with one strain of Actinomyces naeslundii. Coaggregation with F. nucleatum was completely abolished by heating of F. nucleatum cells. Neither lactose nor EDTA reversed the coaggregation. Streptococcus sanguis competed with staphylococci for coaggregation with F. nucleatum and decreased the cell number of staphylococci interacting with F. nucleatum. Sixteen out of 20 staphylococcal strains were aggregated by whole saliva. These results suggest that both MSSA and MRSA possess the potential to colonize dental plaque and that the suppression of normal microflora as well as saliva-mediated aggregation may influence their colonization.
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  • Kensuke Yamamura, Kyuhachiro Shimada, Yoshiaki Yamada
    1994 Volume 36 Issue 5 Pages 526-535
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    The effects of the application of force to a tooth on respiratory activity were investigated in anaesthetized rabbits. Three types of force stimuli were used: 1) continuous force (1kgf for 15s) to the upper incisor, 2) repetitive force (1kgf 80/min for 15s) to the upper incisor and 3) biting of a wooden stick during cortically induced rhythmic jaw movements. Each of the force stimuli elicited an augmenting respiratory reflex. This reflex was characterized by an increase in inspiratory activity (EMG activity in the diaphragm), a decrease in expiratory activity (EMG activity in middle pharyngeal constrictor), and an increase in the respiratory rate. This latter increase was caused primarily by a decrease in the duration of the expiratory phase. Inhibition of expiratory activity was greater with repetitive stimulation than with continuous stimulation. After electrical stimulation of the cortical masticatory area, stable respiratory rhythm became unstable. However, rhythmicity was re-established with repetitive periodontal stimulation in the form of rhythmic biting on a wooden stick.
    These results suggest that the augmenting respiratory reflex mediated by periodontal mechanoreceptors affects respiration when biting may occur during mastication.
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  • Histological and three dimensional examin
    Takanori Matsuoka, Shigeo Aiyama, Etsuro Hanawa
    1994 Volume 36 Issue 5 Pages 536-541
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    An ampulla was found in the main excretory duct (MED) of a mouse submandibular gland. The major aim of the present study was to examine the structure of this ampulla and to consider its functional characteristics. The MED was cut together with the lower jaw and studied by light and electron microscopy, and with a computer system to determine its three-dimensional structure. The ampulla was formed as a part of the MED within the submucosa of the floor of the oral cavity close to the caruncula sublingualis. The ampulla had a pseudostratified epithelium composed of light, dark and basal cells. The anterior wall of the ampulla was in contact with the mandible, and the lateral, medial, inferior and posterior walls were surrounded by striated muscle fibers from the suprahyoid muscle.
    These findings suggest that the ampulla temporarily stores saliva, modifies its composition, and then excretes it in response to demand.
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  • Hiroaki Kobayashi, Kyuhachiro Shimada
    1994 Volume 36 Issue 5 Pages 542-553
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
    Rabbits were lightly anesthetized at different ages (2-days-old to over 60-days-old) to examine the effects of intraoral inputs on peripherally induced rhythmic jaw movement without any tooth contact. Intraoral inputs were applied by placing a rubber tube (2.5mm in diameter) between opposing incisors, molars and alveolar mucosae (diastema) during rhythmic jaw movement.
    The effects of intraoral inputs in young and adult rabbits were extremely different with regard to jaw muscle activities and jaw movements. The most prominent age-related differences in the effects involved the incisal inputs. In young rabbits, the activities of jaw-closing muscles were reduced by incisal inputs, while those of the jaw-opening muscles were facilitated. Opposite effects were observed in adult rabbits. Incisal inputs also gradually changed simple jaw movement to a complicated movement with a wide lateral swing as the animal grew.
    The effect began to change coincident with molar eruption, and stabilized at about the second week after birth, when the animal began to be weaned.
    The present results revealed that intraoral inputs had different effects on jaw movements in young and adult rabbits and that this difference might be related to the transition from sucking to chewing.
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  • Three-dimensional organization of collagen fibrils in the monkey mandibular condylar cartilage
    Kazuyuki Segawa, Atsuko Koide, Reiji Takiguchi
    1994 Volume 36 Issue 5 Pages 554-557
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
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  • Distribution of dental caries cavities in the Neolithic Jomon population of Japan
    Hisashi Fujita, Takao Suzuki, Naoyoshi Ishiyama, Hirohiko Hirano, Ikum ...
    1994 Volume 36 Issue 5 Pages 558-561
    Published: October 20, 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
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  • 1994 Volume 36 Issue 5 Pages e1
    Published: 1994
    Released on J-STAGE: October 28, 2010
    JOURNAL FREE ACCESS
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