toshiro sakae - Academia.edu (original) (raw)
Papers by toshiro sakae
International Journal of Oral-Medical Sciences, 2016
The salivary glands help to keep the mouth and other parts of the digestive system moist. There h... more The salivary glands help to keep the mouth and other parts of the digestive system moist. There have been only a few reports on the salivary glands of the marsupial gray short-tailed opossum(Monodelphis domestica). The aim of this study was to reveal the ultrastructure of the parotid and submandibular glands in the gray short-tailed opossum using transmission electron microscopy(TEM). Using TEM, the parotid glands were found to consist only of serous acinar cells. Secretory granules were highly electron dense. The submandibular glands were composed of both serous and mucous acinar cells, showing a mixture of glands. Also, the submandibular glands possessed special serous cells. Secretory granules were divided into homogeneous density type, two biphasic types and annual ring types. The properties of the granules were different in each cell type. However, some cells contained a mixture of every type of granule. It appeared that the variety of granules in the special serous cells represented stages in the cell cycle and was not a property of the cell. Striated ducts of submandibular glands consisted both of columnar epithelium with or without basal infoldings, although typical striated ducts were found in parotid glands.
Journal of Hard Tissue Biology, 2016
Periodontitis is a highly prevalent chronic inflammatory disease caused by anaerobic gram-negativ... more Periodontitis is a highly prevalent chronic inflammatory disease caused by anaerobic gram-negative oral infection. A clinical diagnosis of periodontitis is made by measuring alveolar bone loss on radiological examination. Mandibular bone mainly consists of cancellous bone and bone marrow. However, radiological examination reveals only cortical bone resorption, and does not provide complete information concerning the bony conditions, such as histopathological changes in the bone marrow. Evaluation of bone marrow is critical for the diagnosis, treatment and prognosis of patients with various diseases. However, little is known about the association between periodontitis and bone marrow edema in the mandible. The purpose of this study was to use Magnetic resonance imaging (MRI) to investigate bone marrow edema caused by periodontitis in the mandible. This prospective study included 104 patients (52 men, 52 women; 21-78 years of age, mean age 56.3 years) evaluated during a 6-year period from August 2006 to August 2012. Periodontal condition and MR signal intensity of the mandibular bone marrow were evaluated in all patients. Six regions, (bilateral incisors, premolar teeth, and molar teeth) were evaluated. MRI revealed bone marrow edema at 365 of 412 sites evaluated (88.6 %). In conclusion MRI revealed bone marrow abnormalities in a high percentage of mandibular regions with periodontitis, suggesting that bone marrow edema in the mandible can be caused by periodontitis.
Journal of Hard Tissue Biology, 2016
Distinguishing normal parts of the nasopalatine duct from nonodontogenic nasopalatine duct cysts ... more Distinguishing normal parts of the nasopalatine duct from nonodontogenic nasopalatine duct cysts can be difficult. This study aimed to establish the characteristic imaging findings of the nasopalatine duct region on multidetector-row computed tomographic (MDCT) images. The subjects were 122 patients (61 males, 61 females; mean age, 49.8 years; age range, 17-88 years) who underwent 64-MDCT imaging of the maxilla after providing informed consent. Anatomic variants of the nasopalatine duct were classified using coronal slices. Measurements of the duct width diameters and the distances from the nasopalatine foramen to the incisive foramen as a major axis were performed using sagittal and coronal slices. CT values for the duct portion with maximum diameter were measured using axial slices. Regarding anatomic variations, 69 patients (56.5 %) had a single duct, 13 patients (10.7 %) had two parallel ducts, and 40 patients (32.8 %) had Y-type ducts. The mean width diameter of the nasopalatine duct on sagittal slices was 3.2 mm in the nasopalatine foramen, 2.7 mm in the middle point, and 3.1 mm in the incisive foramen. The mean width diameter of the nasopalatine duct on coronal slices was 4.3 mm in the nasopalatine foramen, 3.6 mm in the middle point, and 3.8 mm in the incisive foramen. The mean CT value in males and females was 122.4 ± 77.9 HU. Although the nasopalatine duct shows great variability in morphological appearance, characteristic findings for the nasopalatine duct region on MDCT images have been established in this study.
International Journal of Oral-Medical Sciences, 2008
Journal of Hard Tissue Biology, 2012
A convenient silver staining method generally used in marking proteins in polyacrylamide gel was ... more A convenient silver staining method generally used in marking proteins in polyacrylamide gel was applied to stain undecalcified tooth sections for clear observation of fine structures in tooth tissues. Ground sections of teeth were directly soaked and stained with a solution prepared according to the staining protocol. Although modification of the staining procedure might be necessary to establish favorable staining condition in tooth sections, observation of fine structures in tooth sections became easy with the staining technique.
Journal of Hard Tissue Biology, 2012
Signaling pathways have been shown to participate in the process of Retinoic acid (RA)-induced cl... more Signaling pathways have been shown to participate in the process of Retinoic acid (RA)-induced cleft palate (CP). In our current study, the signaling molecules of GSK-3β, Fzd3 and β-TrCP, which all relate with Wnt pathway, were screened from the palate tissues of the RA-induced CP in mice by the Gene-chip Technology. But, their expression pattern and level in palates during perinatal stages have not been known yet. In the studies, mRNA level of GSK-3β, Fzd3 and β-TrCP were detected by quantitative real-time PCR, and showed significant difference between the Embryonic day 18 (ED18) before birth and Postnatal day 0 (PD0) after birth, as well as between the RAinduced CP and wild type during the perinatal stage, respectively. And the localization pattern of GSK-3β, Fzd3 and β-TrCP proteins in palates was also characterized. Our data indicates that the Wnt signaling pathway may involve in the RA-induced cleft palate during peirnatal stage.
Japanese Journal of Oral & Maxillofacial Surgery, 1980
The Journal of Nihon University School of Dentistry, 1989
The crystallographic properties of hydroxyapatites synthesized at temperastructure, and that the ... more The crystallographic properties of hydroxyapatites synthesized at temperastructure, and that the structure was depleted of carbonate ions at about 500•Ž.
Calcified Tissue Research, 1976
The morphologic structure of anorganic dental calculus was studied by means of the scanning elect... more The morphologic structure of anorganic dental calculus was studied by means of the scanning electron microscope. From surface observations, calculus is apparently composed of two components with distinguishable patters of calcification. One component is formed by the precipitation of minute calcific crystals on microorganisms and intermicrobial substances (plaque matrix). Such calcified masses, often spherical in shape, have a sponge-like appearance with empty spaces representing the former sites of entombed and degenerated organisms. Thus, intracellular calcification is not evident at this stage of calculus development. The other component, although having at least one common calcification front with the former, does not appear to be directly associated with microbial calcification. It exhibits a configuration of generally larger crystal growths of varying shapes and sizes. These two calcification patterns are comparable, both in distribution and size, to what has been observed by means of the transmission electron microscope, and what Schroeder has designated as "types A& B centers of mineralization," respectively. The calcific precipitation in type A centers have been identified by X-ray diffraction as hydroxyapatite. It is, therefore, speculated that the crystal patters in type B centers might represent other known forms of calcium phosphates present in calculus, such as octacalcium phosphate, whitlockite and brushite.
Minerals, 2022
Biological apatite in enamel, dentin, cementum, and bone is highly individualized hydroxyapatite ... more Biological apatite in enamel, dentin, cementum, and bone is highly individualized hydroxyapatite with high tissue dependency. Often, standard and average textbook values for biological apatite do not apply to actual subjects, and the reported results of analyses differ among investigators. In particular, the term biological apatite is often confusingly and incorrectly used to describe carbonate apatite. The purpose of this review is to prevent further confusion. We believe that apatite should be well understood across disciplines and the terminology clearly defined. According to a definition by the International Mineralogical Association’s Commission on New Minerals Nomenclature and Classification, biological apatite formed by living organisms is a type of hydroxyapatite. More specifically, it is carbonated hydroxyapatite, which is quite different from frequently misnamed carbonate apatite. We hope that this definition will be widely adopted to remove confusion around the naming of ...
Bioceramics Development and Applications, 2013
Bone mineral density; Bone strength; Micro-CT Measurements of bone mineral density (BMD) and thre... more Bone mineral density; Bone strength; Micro-CT Measurements of bone mineral density (BMD) and threedimensional color mapping (3D-map) Micro-CT settings: Femoral micro-CT images (Figure 1A) were acquired setting the measurement range at the middle point region of the full femoral length measured using calipers (Figure 1B). The micro-CT was carried out using a R_mCT (Rigaku Co., Japan). The value of BMD was measured using TRI/3D-Bon BMD software (TRI/3D; Ratoc System Engineering Co., Japan). Three-dimensional color mapping (3D-map) of the BMD distributions was carried out using TRI/3D image analysis software. Measurements of bone strength Bone strength was measured using an Instron type testing machine system (Figure 1C), TG-5kN, Minebea Co., Japan). Bending force was loaded on the middle point of the bone length at 5.0 mm/min. Statistical analysis The means and standard deviations of body weight, BMD, and bone strength were calculated for each group and compared using Student's t-test.
Journal of Hard Tissue Biology, 2016
The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improve... more The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improves peri-implant bone formation and bone micro architecture (BMA). SBM was used as and intervention experimental diet and AIN-93M was used as a control. The SBM was prepared by mixing dicalcium phosphate dihydrate (CaHPO4.2H2O) and magnesium and zinc chlorides (MgCl2 and ZnCl2, respectively), and hydrolyzed in double-distilled water containing dissolved potassium carbonate and sodium fluoride. All rats were randomly allocated into one of two groups: a control group was fed without SBM (n = 18) or an experimental group was fed with SBM (n = 18), at seven weeks old. At 9 weeks old, all rats underwent implant surgery on their femurs under general anesthesia. The implant was inserted into the insertion socket prepared at rats' femur to a depth of 2.5 mm by using a drill at 500 rpm. Nine rats in each group were randomly selected and euthanized at 2 weeks after implantation. The remaining nine rats in each group continued their diets, and were euthanized in the same manner at 4 weeks after implantation. The femur, including the implant, was removed from the body and implant was pulled out by an Instron universal testing machine. After the implant removal, BMA was evaluated by bone surface ratio (BS/BV), bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN), trabecular star volume (Vtr), and micro-CT images. BS/BV, BV/TV, TbTh and Vtr were significantly greater in the rats were fed with SBM than those were fed without SBM at 2 and 4 weeks after implantation (P < 0.05). The present results revealed that SBM improves the peri-implant formation and BMA, prominent with trabecular bone structure. The effect of SBM to improve secondary stability of the implant, and shortening the treatment period should be investigated in the future study.
International Journal of Oral-Medical Sciences, 2008
Journal of Hard Tissue Biology, 2009
Cementum is divided into acellular cementum and cellular cementum based on the absence and presen... more Cementum is divided into acellular cementum and cellular cementum based on the absence and presence of cementocytes in the cementum matrix. Since the distribution of acellular and cellular cementum is affected by physical conditions such as aging and pathological conditions like inflammation and hyper occlusal pressure causing hypercementosis. Moreover, it has been reported in many text books that acellular and cellular cementum distribute irregularly. However, it is generally known that acellular cementum is located from the cervical margin to the cervical half or one-third and cellular cementum is observed from the apical half or two-thirds to the apical portion. In the present study, we have observed labio-lingual grinding sections of extracted human permanent teeth used for student practice (50 incisors and 78 molars) and classified the distribution pattern of acellular and cellular cementum into five types as following: 1) Typical distribution type of the acellular and cellular cementum as explained above, 2) Type with thick acellular cementum at the cervical portion. In this type, thick acellular cementum is observed at the cervical portion, although the acellular and cellular cementum is distributed as same as type 1 except in the cervical portion, 3) Type with thick cellular cementum at the cervical portion. This type showed that thick cellular cementum is distributed at the cervical portion instead of acellular cementum in type 2, 4) Type with acellular cementum from the cervical area to apical portion. This type showed acellular cementum covering from the cervical to apical portion of the tooth root surface, although the cellular cementum was located near the dentino-cement junction, 5) Type with cellular cementum from the cervical to apical portion. Cellular cementum distributed from the cervical to apical portion of the tooth root surface, although the acellular cementum is located inside the surface cellular cementum. In type 5, we found holes of various sizes and shapes in the hypertrophied cementum. Since these holes were large and cement canaliculus surrounding the holes extended toward the holes, it is suggested that the hypertrophied cementum enfolded a part of the periodontal ligament.
Journal of Hard Tissue Biology, 2005
Enamel covers the dentin in mammalian teeth. It is believed that the enamel structure reflects th... more Enamel covers the dentin in mammalian teeth. It is believed that the enamel structure reflects the function of teeth, since the enamel structure is different depending on an animal's feeding habits. Tooth germ transplantation is a popular method for developmental and tissue engineering research. However, there is little information about the structure of the enamel of transplanted tooth germ, although tooth structure, especially enamel structure, is very important for the function of teeth. In this study, the enamel structure of E13.5 mouse mandible first molars transplanted into the kidney capsule was observed by scanning electron microscopy. Many part of the tooth crown are formed at transplantation 7 day. Although enamel and dentin were observed at the cusp portion, hard tissue was not formed at the cervical portion. The enamel prisms were observed at day 21 after transplantation. The enamel was divided into three layers according to the running pattern of the enamel prisms as normal tooth germ in vivo. However, the width of the various layers was different. It seems likely that the microenvironment surrounding tooth germ may play an important role in determining the structure of the enamel, since normal tooth germ grows in the calcified alveolar bone according as development.
Journal of Hard Tissue Biology, 2007
The purpose of this study was to evaluate synthetic calcium phosphates and animal bones using Ram... more The purpose of this study was to evaluate synthetic calcium phosphates and animal bones using Raman spectroscopy, and explore the possibility of its application in characterizing newly formed bone around implants. Synthetic calcium phosphates (monobasic calcium phosphate, dibasic calcium phosphate and tribasic calcium phosphate), hydroxyapatite and rabbit bones with and without implants were analyzed in this study. Slight differences in the Raman bands among the 3 types of synthetic calcium phosphate and hydroxyapatite were observed. Furthermore, a 3 cm-1 difference was noted in the bands of the main PO 4 3in rabbit's bone formed around the implant compared to the existing bone, suggesting a difference in the molecular structure between the existing and newly formed bone.
Journal of Hard Tissue Biology, 2007
The aim of this study is to observe the three-dimensional structure of cancellous bone formed aro... more The aim of this study is to observe the three-dimensional structure of cancellous bone formed around dental implants using micro-CT.Methods: Ti implants (Ti-15%Zr-4%Nb-4%Ta alloy, 2.8mm diameter, 10mm length, machine-polished) were placed in surgically created bone defects in rabbit femurs (New Zealand White Rabbits). The rabbit femurs with the implants were removed 6 weeks after implantation and preserved in formalin. Micro-CT analysis was performed using three types of machine, TOSCANER-31300 mhd ® (Voltage:
Japanese Journal of Oral Biology, 2002
The aim of this study was to elucidate the three genotypes (op/op, op/+ and +/+) of heterogenous ... more The aim of this study was to elucidate the three genotypes (op/op, op/+ and +/+) of heterogenous osteopetrotic mice using microsatellite markers. The genotyping analysis was performed on genetic crosses using B6C3Fe-op/+ and A/WySnJ mice. In this study, we used five MIT markers, D3Mit11, 75, 101, 102 and 189 that are closely linked to the op locus and which segregate polymorphic variants in mating between B6C3Fe-op/+ and A/WySnJ mice, and the homozygous op/op F3 mice were obtained by F2 mice mating. From the results of F3 genotyping, it was possible to determine the genotype of the op gene without a complicated molecular process. Histopathological studies revealed that the F3-op/op mice showed similar femur bone structures to those of B6C3Fe-op/op mice. Based on these findings, it is suggested that genotyping of heterogenous osteopetrotic mice using microsatellite markers is a powerful technique for investigating the mechanism of osteoclast development and genetic studies of osteopetrosis.
International Journal of Oral-Medical Sciences, 2004
We present a case involving an unusually large calculus of Wharton's duct. To gain insight into t... more We present a case involving an unusually large calculus of Wharton's duct. To gain insight into the formation of this calculus, detailed structural properties were investigated using an X-ray diffraction technique. A 70-year old man, brought a calculus to a dental consultation, by himself, when it pelforated the floor of the mouth. The calculus was unusually long, measuring 4.5 cm in length. X-ray diffraction and micro-FT-1R analyses were employed to investigate structural properties of the calculus, which suggested that its stratified structure, reflecting compositional changes in the microenvironment, was a result of intemuttent and incremental growth.
International Journal of Oral-Medical Sciences, 2016
The salivary glands help to keep the mouth and other parts of the digestive system moist. There h... more The salivary glands help to keep the mouth and other parts of the digestive system moist. There have been only a few reports on the salivary glands of the marsupial gray short-tailed opossum(Monodelphis domestica). The aim of this study was to reveal the ultrastructure of the parotid and submandibular glands in the gray short-tailed opossum using transmission electron microscopy(TEM). Using TEM, the parotid glands were found to consist only of serous acinar cells. Secretory granules were highly electron dense. The submandibular glands were composed of both serous and mucous acinar cells, showing a mixture of glands. Also, the submandibular glands possessed special serous cells. Secretory granules were divided into homogeneous density type, two biphasic types and annual ring types. The properties of the granules were different in each cell type. However, some cells contained a mixture of every type of granule. It appeared that the variety of granules in the special serous cells represented stages in the cell cycle and was not a property of the cell. Striated ducts of submandibular glands consisted both of columnar epithelium with or without basal infoldings, although typical striated ducts were found in parotid glands.
Journal of Hard Tissue Biology, 2016
Periodontitis is a highly prevalent chronic inflammatory disease caused by anaerobic gram-negativ... more Periodontitis is a highly prevalent chronic inflammatory disease caused by anaerobic gram-negative oral infection. A clinical diagnosis of periodontitis is made by measuring alveolar bone loss on radiological examination. Mandibular bone mainly consists of cancellous bone and bone marrow. However, radiological examination reveals only cortical bone resorption, and does not provide complete information concerning the bony conditions, such as histopathological changes in the bone marrow. Evaluation of bone marrow is critical for the diagnosis, treatment and prognosis of patients with various diseases. However, little is known about the association between periodontitis and bone marrow edema in the mandible. The purpose of this study was to use Magnetic resonance imaging (MRI) to investigate bone marrow edema caused by periodontitis in the mandible. This prospective study included 104 patients (52 men, 52 women; 21-78 years of age, mean age 56.3 years) evaluated during a 6-year period from August 2006 to August 2012. Periodontal condition and MR signal intensity of the mandibular bone marrow were evaluated in all patients. Six regions, (bilateral incisors, premolar teeth, and molar teeth) were evaluated. MRI revealed bone marrow edema at 365 of 412 sites evaluated (88.6 %). In conclusion MRI revealed bone marrow abnormalities in a high percentage of mandibular regions with periodontitis, suggesting that bone marrow edema in the mandible can be caused by periodontitis.
Journal of Hard Tissue Biology, 2016
Distinguishing normal parts of the nasopalatine duct from nonodontogenic nasopalatine duct cysts ... more Distinguishing normal parts of the nasopalatine duct from nonodontogenic nasopalatine duct cysts can be difficult. This study aimed to establish the characteristic imaging findings of the nasopalatine duct region on multidetector-row computed tomographic (MDCT) images. The subjects were 122 patients (61 males, 61 females; mean age, 49.8 years; age range, 17-88 years) who underwent 64-MDCT imaging of the maxilla after providing informed consent. Anatomic variants of the nasopalatine duct were classified using coronal slices. Measurements of the duct width diameters and the distances from the nasopalatine foramen to the incisive foramen as a major axis were performed using sagittal and coronal slices. CT values for the duct portion with maximum diameter were measured using axial slices. Regarding anatomic variations, 69 patients (56.5 %) had a single duct, 13 patients (10.7 %) had two parallel ducts, and 40 patients (32.8 %) had Y-type ducts. The mean width diameter of the nasopalatine duct on sagittal slices was 3.2 mm in the nasopalatine foramen, 2.7 mm in the middle point, and 3.1 mm in the incisive foramen. The mean width diameter of the nasopalatine duct on coronal slices was 4.3 mm in the nasopalatine foramen, 3.6 mm in the middle point, and 3.8 mm in the incisive foramen. The mean CT value in males and females was 122.4 ± 77.9 HU. Although the nasopalatine duct shows great variability in morphological appearance, characteristic findings for the nasopalatine duct region on MDCT images have been established in this study.
International Journal of Oral-Medical Sciences, 2008
Journal of Hard Tissue Biology, 2012
A convenient silver staining method generally used in marking proteins in polyacrylamide gel was ... more A convenient silver staining method generally used in marking proteins in polyacrylamide gel was applied to stain undecalcified tooth sections for clear observation of fine structures in tooth tissues. Ground sections of teeth were directly soaked and stained with a solution prepared according to the staining protocol. Although modification of the staining procedure might be necessary to establish favorable staining condition in tooth sections, observation of fine structures in tooth sections became easy with the staining technique.
Journal of Hard Tissue Biology, 2012
Signaling pathways have been shown to participate in the process of Retinoic acid (RA)-induced cl... more Signaling pathways have been shown to participate in the process of Retinoic acid (RA)-induced cleft palate (CP). In our current study, the signaling molecules of GSK-3β, Fzd3 and β-TrCP, which all relate with Wnt pathway, were screened from the palate tissues of the RA-induced CP in mice by the Gene-chip Technology. But, their expression pattern and level in palates during perinatal stages have not been known yet. In the studies, mRNA level of GSK-3β, Fzd3 and β-TrCP were detected by quantitative real-time PCR, and showed significant difference between the Embryonic day 18 (ED18) before birth and Postnatal day 0 (PD0) after birth, as well as between the RAinduced CP and wild type during the perinatal stage, respectively. And the localization pattern of GSK-3β, Fzd3 and β-TrCP proteins in palates was also characterized. Our data indicates that the Wnt signaling pathway may involve in the RA-induced cleft palate during peirnatal stage.
Japanese Journal of Oral & Maxillofacial Surgery, 1980
The Journal of Nihon University School of Dentistry, 1989
The crystallographic properties of hydroxyapatites synthesized at temperastructure, and that the ... more The crystallographic properties of hydroxyapatites synthesized at temperastructure, and that the structure was depleted of carbonate ions at about 500•Ž.
Calcified Tissue Research, 1976
The morphologic structure of anorganic dental calculus was studied by means of the scanning elect... more The morphologic structure of anorganic dental calculus was studied by means of the scanning electron microscope. From surface observations, calculus is apparently composed of two components with distinguishable patters of calcification. One component is formed by the precipitation of minute calcific crystals on microorganisms and intermicrobial substances (plaque matrix). Such calcified masses, often spherical in shape, have a sponge-like appearance with empty spaces representing the former sites of entombed and degenerated organisms. Thus, intracellular calcification is not evident at this stage of calculus development. The other component, although having at least one common calcification front with the former, does not appear to be directly associated with microbial calcification. It exhibits a configuration of generally larger crystal growths of varying shapes and sizes. These two calcification patterns are comparable, both in distribution and size, to what has been observed by means of the transmission electron microscope, and what Schroeder has designated as "types A& B centers of mineralization," respectively. The calcific precipitation in type A centers have been identified by X-ray diffraction as hydroxyapatite. It is, therefore, speculated that the crystal patters in type B centers might represent other known forms of calcium phosphates present in calculus, such as octacalcium phosphate, whitlockite and brushite.
Minerals, 2022
Biological apatite in enamel, dentin, cementum, and bone is highly individualized hydroxyapatite ... more Biological apatite in enamel, dentin, cementum, and bone is highly individualized hydroxyapatite with high tissue dependency. Often, standard and average textbook values for biological apatite do not apply to actual subjects, and the reported results of analyses differ among investigators. In particular, the term biological apatite is often confusingly and incorrectly used to describe carbonate apatite. The purpose of this review is to prevent further confusion. We believe that apatite should be well understood across disciplines and the terminology clearly defined. According to a definition by the International Mineralogical Association’s Commission on New Minerals Nomenclature and Classification, biological apatite formed by living organisms is a type of hydroxyapatite. More specifically, it is carbonated hydroxyapatite, which is quite different from frequently misnamed carbonate apatite. We hope that this definition will be widely adopted to remove confusion around the naming of ...
Bioceramics Development and Applications, 2013
Bone mineral density; Bone strength; Micro-CT Measurements of bone mineral density (BMD) and thre... more Bone mineral density; Bone strength; Micro-CT Measurements of bone mineral density (BMD) and threedimensional color mapping (3D-map) Micro-CT settings: Femoral micro-CT images (Figure 1A) were acquired setting the measurement range at the middle point region of the full femoral length measured using calipers (Figure 1B). The micro-CT was carried out using a R_mCT (Rigaku Co., Japan). The value of BMD was measured using TRI/3D-Bon BMD software (TRI/3D; Ratoc System Engineering Co., Japan). Three-dimensional color mapping (3D-map) of the BMD distributions was carried out using TRI/3D image analysis software. Measurements of bone strength Bone strength was measured using an Instron type testing machine system (Figure 1C), TG-5kN, Minebea Co., Japan). Bending force was loaded on the middle point of the bone length at 5.0 mm/min. Statistical analysis The means and standard deviations of body weight, BMD, and bone strength were calculated for each group and compared using Student's t-test.
Journal of Hard Tissue Biology, 2016
The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improve... more The present animal study investigated whether oral intake of synthetic bone mineral (SBM) improves peri-implant bone formation and bone micro architecture (BMA). SBM was used as and intervention experimental diet and AIN-93M was used as a control. The SBM was prepared by mixing dicalcium phosphate dihydrate (CaHPO4.2H2O) and magnesium and zinc chlorides (MgCl2 and ZnCl2, respectively), and hydrolyzed in double-distilled water containing dissolved potassium carbonate and sodium fluoride. All rats were randomly allocated into one of two groups: a control group was fed without SBM (n = 18) or an experimental group was fed with SBM (n = 18), at seven weeks old. At 9 weeks old, all rats underwent implant surgery on their femurs under general anesthesia. The implant was inserted into the insertion socket prepared at rats' femur to a depth of 2.5 mm by using a drill at 500 rpm. Nine rats in each group were randomly selected and euthanized at 2 weeks after implantation. The remaining nine rats in each group continued their diets, and were euthanized in the same manner at 4 weeks after implantation. The femur, including the implant, was removed from the body and implant was pulled out by an Instron universal testing machine. After the implant removal, BMA was evaluated by bone surface ratio (BS/BV), bone volume fraction (BV/TV), trabecular thickness (TbTh), trabecular number (TbN), trabecular star volume (Vtr), and micro-CT images. BS/BV, BV/TV, TbTh and Vtr were significantly greater in the rats were fed with SBM than those were fed without SBM at 2 and 4 weeks after implantation (P < 0.05). The present results revealed that SBM improves the peri-implant formation and BMA, prominent with trabecular bone structure. The effect of SBM to improve secondary stability of the implant, and shortening the treatment period should be investigated in the future study.
International Journal of Oral-Medical Sciences, 2008
Journal of Hard Tissue Biology, 2009
Cementum is divided into acellular cementum and cellular cementum based on the absence and presen... more Cementum is divided into acellular cementum and cellular cementum based on the absence and presence of cementocytes in the cementum matrix. Since the distribution of acellular and cellular cementum is affected by physical conditions such as aging and pathological conditions like inflammation and hyper occlusal pressure causing hypercementosis. Moreover, it has been reported in many text books that acellular and cellular cementum distribute irregularly. However, it is generally known that acellular cementum is located from the cervical margin to the cervical half or one-third and cellular cementum is observed from the apical half or two-thirds to the apical portion. In the present study, we have observed labio-lingual grinding sections of extracted human permanent teeth used for student practice (50 incisors and 78 molars) and classified the distribution pattern of acellular and cellular cementum into five types as following: 1) Typical distribution type of the acellular and cellular cementum as explained above, 2) Type with thick acellular cementum at the cervical portion. In this type, thick acellular cementum is observed at the cervical portion, although the acellular and cellular cementum is distributed as same as type 1 except in the cervical portion, 3) Type with thick cellular cementum at the cervical portion. This type showed that thick cellular cementum is distributed at the cervical portion instead of acellular cementum in type 2, 4) Type with acellular cementum from the cervical area to apical portion. This type showed acellular cementum covering from the cervical to apical portion of the tooth root surface, although the cellular cementum was located near the dentino-cement junction, 5) Type with cellular cementum from the cervical to apical portion. Cellular cementum distributed from the cervical to apical portion of the tooth root surface, although the acellular cementum is located inside the surface cellular cementum. In type 5, we found holes of various sizes and shapes in the hypertrophied cementum. Since these holes were large and cement canaliculus surrounding the holes extended toward the holes, it is suggested that the hypertrophied cementum enfolded a part of the periodontal ligament.
Journal of Hard Tissue Biology, 2005
Enamel covers the dentin in mammalian teeth. It is believed that the enamel structure reflects th... more Enamel covers the dentin in mammalian teeth. It is believed that the enamel structure reflects the function of teeth, since the enamel structure is different depending on an animal's feeding habits. Tooth germ transplantation is a popular method for developmental and tissue engineering research. However, there is little information about the structure of the enamel of transplanted tooth germ, although tooth structure, especially enamel structure, is very important for the function of teeth. In this study, the enamel structure of E13.5 mouse mandible first molars transplanted into the kidney capsule was observed by scanning electron microscopy. Many part of the tooth crown are formed at transplantation 7 day. Although enamel and dentin were observed at the cusp portion, hard tissue was not formed at the cervical portion. The enamel prisms were observed at day 21 after transplantation. The enamel was divided into three layers according to the running pattern of the enamel prisms as normal tooth germ in vivo. However, the width of the various layers was different. It seems likely that the microenvironment surrounding tooth germ may play an important role in determining the structure of the enamel, since normal tooth germ grows in the calcified alveolar bone according as development.
Journal of Hard Tissue Biology, 2007
The purpose of this study was to evaluate synthetic calcium phosphates and animal bones using Ram... more The purpose of this study was to evaluate synthetic calcium phosphates and animal bones using Raman spectroscopy, and explore the possibility of its application in characterizing newly formed bone around implants. Synthetic calcium phosphates (monobasic calcium phosphate, dibasic calcium phosphate and tribasic calcium phosphate), hydroxyapatite and rabbit bones with and without implants were analyzed in this study. Slight differences in the Raman bands among the 3 types of synthetic calcium phosphate and hydroxyapatite were observed. Furthermore, a 3 cm-1 difference was noted in the bands of the main PO 4 3in rabbit's bone formed around the implant compared to the existing bone, suggesting a difference in the molecular structure between the existing and newly formed bone.
Journal of Hard Tissue Biology, 2007
The aim of this study is to observe the three-dimensional structure of cancellous bone formed aro... more The aim of this study is to observe the three-dimensional structure of cancellous bone formed around dental implants using micro-CT.Methods: Ti implants (Ti-15%Zr-4%Nb-4%Ta alloy, 2.8mm diameter, 10mm length, machine-polished) were placed in surgically created bone defects in rabbit femurs (New Zealand White Rabbits). The rabbit femurs with the implants were removed 6 weeks after implantation and preserved in formalin. Micro-CT analysis was performed using three types of machine, TOSCANER-31300 mhd ® (Voltage:
Japanese Journal of Oral Biology, 2002
The aim of this study was to elucidate the three genotypes (op/op, op/+ and +/+) of heterogenous ... more The aim of this study was to elucidate the three genotypes (op/op, op/+ and +/+) of heterogenous osteopetrotic mice using microsatellite markers. The genotyping analysis was performed on genetic crosses using B6C3Fe-op/+ and A/WySnJ mice. In this study, we used five MIT markers, D3Mit11, 75, 101, 102 and 189 that are closely linked to the op locus and which segregate polymorphic variants in mating between B6C3Fe-op/+ and A/WySnJ mice, and the homozygous op/op F3 mice were obtained by F2 mice mating. From the results of F3 genotyping, it was possible to determine the genotype of the op gene without a complicated molecular process. Histopathological studies revealed that the F3-op/op mice showed similar femur bone structures to those of B6C3Fe-op/op mice. Based on these findings, it is suggested that genotyping of heterogenous osteopetrotic mice using microsatellite markers is a powerful technique for investigating the mechanism of osteoclast development and genetic studies of osteopetrosis.
International Journal of Oral-Medical Sciences, 2004
We present a case involving an unusually large calculus of Wharton's duct. To gain insight into t... more We present a case involving an unusually large calculus of Wharton's duct. To gain insight into the formation of this calculus, detailed structural properties were investigated using an X-ray diffraction technique. A 70-year old man, brought a calculus to a dental consultation, by himself, when it pelforated the floor of the mouth. The calculus was unusually long, measuring 4.5 cm in length. X-ray diffraction and micro-FT-1R analyses were employed to investigate structural properties of the calculus, which suggested that its stratified structure, reflecting compositional changes in the microenvironment, was a result of intemuttent and incremental growth.