The Experts below are selected from a list of 45462 Experts worldwide ranked by ideXlab platform
Hidehiro Ozawa - One of the best experts on this subject based on the ideXlab platform.
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Potential of Periodontal Ligament Cells to Regenerate Alveolar Bone
Journal of Oral Biosciences, 2010Co-Authors: Akihiro Hosoya, Tadashi Ninomiya, Toru Hiraga, Kunihiko Yoshiba, Nagako Yoshiba, Etsuo Kasahara, Hidehiro Ozawa, Hiroaki NakamuraAbstract:Regeneration of periodontal tissues, lost as a result of periodontal disease, is a key objective of periodontal treatment. Although several periodontal regeneration therapies have been devised, the origin of the undifferentiated cells that regenerate periodontal tissues remains unknown. Therefore, in the present study, to clarify the existence of osteoblast progenitor cells in the periodontal ligament, as well as to investigate the mechanism of Alveolar Bone regeneration without any effects from the original Bone, we evaluated osteoblast differentiation induced by transplantation of GFP-transgenic rat molars into the subcutaneous tissues of wild-type rats. Ten days after transplantation, initial Alveolar Bone was formed apart from the cementum in the bifurcation region. After 20 days, this Bone tissue had expanded to almost all of the bifurcation. GFP localization showed that the osteoblasts were derived from the transplant. Alpha-SMA- and BMP4-positive cells were observed near the root surface at 5 days after transplantation. With the progress of Alveolar Bone regeneration, osteoblasts expressing Runx2 and Osterix appeared in the Bone-forming region. These results indicate that periodontal ligament tissue remaining on the root surface after a tooth extraction contains undifferentiated cells that have the ability to regenerate Alveolar Bone. The process of osteoblast differentiation in this model might be similar to that for normal Alveolar Bone formation. Thus, periodontal ligament cells might be useful for the regeneration of Alveolar Bone in tissue engineering applications.
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Effects of ovariectomy on trabecular structures of rat Alveolar Bone
Journal of periodontal research, 2002Co-Authors: Mikako Tanaka, Shoji Kohno, Sadakazu Ejiri, E. Toyooka, Hidehiro OzawaAbstract:An association between postmenopausal osteoporosis and tooth loss has been proposed. However, histomorphometrical changes in Alveolar Bone following estrogen deficiency are rarely reported with data on microtrabecular structural changes. To clarify the relationship between estrogen deficiency and tooth loss, we histomorphometrically analyzed the trabecular structural changes of mandibular Alveolar Bone in ovariectomized rats. Twenty-four adult female Fischer rats were used. Eight rats were sacrificed on day 0 (baseline). The remaining 16 rats were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other group was subjected to sham surgery (Sham). After administration of tetracycline and calcein, the animals were sacrificed 60 days after surgery. Bone histomorphometry, node-strut analysis and measurement of thickness of Alveolar Bone proper were performed on the interradicular septum of the first molar on the sagittal surface. The trabecular Bone volume and trabecular number of the OVX group were significantly lower than those of the baseline and Sham groups. All of the Bone resorptive and formative parameters of the OVX group were significantly higher (about one-and-a-half times) than those of the Sham group. Several osteoclasts were seen lining the irregular, eroded surface facing the Bone marrow in the OVX group. Furthermore, the OVX group tended to have low microtrabecular stiffness and showed significantly thinner distal Alveolar Bone proper than in the baseline and Sham groups. In summary, estrogen deficiency caused osteoporotic changes and thin Alveolar Bone proper in the interradicular septum of rat first molar. This phenomenon might accelerate destruction of Alveolar Bone and tooth loss, especially in elderly women affected by periodontal disease.
Hwa Sung Chae - One of the best experts on this subject based on the ideXlab platform.
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Alveolar Bone remodeling during maxillary incisor intrusion and retraction
Progress in Orthodontics, 2019Co-Authors: Seok Yoon Hong, Jeong Won Shin, Christine Hong, Vania Chan, Un-bong Baik, Hwa Sung ChaeAbstract:Background Maxillary incisor protrusion is a prevalent dental deformity and is often treated by upper incisor intrusion and retraction. The mechanical loading triggers the resorption and apposition of the Bone. Alveolar Bone remodeling is expected to follow orthodontic tooth movement in a one-to-one relationship. However, in many cases, the outcomes are different. Alveolar Bone might still remain thick causing lip protrusion and other aesthetic problems after treatment. Additional corrective procedures such as alveoloplasty. On the other hand, if the labial Bone becomes too thin, periodontal problems like gingival recession might occur. The unpredictability of the treatment result and the risk of requiring corrective procedures pose significant challenges to both the providers and patients. The aim of this study is to determine factors that can help to predict the Alveolar Bone reaction before maxillary incisor intrusion and retraction. Methods The cohort included 34 female patients (mean age 25.8 years) who were diagnosed with skeletal class II malocclusion with upper incisor protrusion. These patients underwent extraction and orthodontic treatment with upper incisor intrusion and retraction. Lateral cephalograms at pre-treatment and post-treatment were taken. Linear and angular measurements were analyzed to evaluate the Alveolar Bone changes based on initial conditions. Results The study found that the relative change, calculated as change in Alveolar Bone thickness after treatment divided by the initial Alveolar thickness, was inversely correlated with the initial thickness. There was a significant increase of labial Alveolar Bone thickness at 9-mm apical from cementoenamel junction (B3) ( P < 0.05) but no statistically significant change in the thickness at other levels. In addition, the change in angulation between the incisor and Alveolar Bone was inversely correlated with several initial angulations: between the initial palatal plane and upper incisor angle, between the initial palatal plane and upper incisor labial surface angle, and between the initial palatal plane and Bone labial surface angle. On the other hand, the change in labial Bone thickness was neither significantly correlated with the initial thickness nor significantly correlated to the amount of retraction. Conclusion The unpredictability of Alveolar Bone remodeling after upper incisor intrusion and retraction poses significant challenges to treatment planning and patient experience. The study showed that the initial angulation between the incisor and Alveolar Bone is correlated with the change in angulation after treatment, the initial thickness of the Alveolar Bone was correlated with the relative change of the Alveolar Bone thickness (defined as change in thickness after treatment divided by its initial thickness), and the amount of intrusion was correlated with the Alveolar Bone thickness change at 9-mm apical from the cementoenamel junction after treatment. The results of the present study also revealed that the change in labial Alveolar Bone thickness was neither significantly correlated with the initial thickness nor significantly correlated to the amount of retraction.
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Alveolar Bone remodeling during maxillary incisor intrusion and retraction
Progress in orthodontics, 2019Co-Authors: Seok Yoon Hong, Jeong Won Shin, Christine Hong, Vania Chan, Un-bong Baik, Young Ho Kim, Hwa Sung ChaeAbstract:Maxillary incisor protrusion is a prevalent dental deformity and is often treated by upper incisor intrusion and retraction. The mechanical loading triggers the resorption and apposition of the Bone. Alveolar Bone remodeling is expected to follow orthodontic tooth movement in a one-to-one relationship. However, in many cases, the outcomes are different. Alveolar Bone might still remain thick causing lip protrusion and other aesthetic problems after treatment. Additional corrective procedures such as alveoloplasty. On the other hand, if the labial Bone becomes too thin, periodontal problems like gingival recession might occur. The unpredictability of the treatment result and the risk of requiring corrective procedures pose significant challenges to both the providers and patients. The aim of this study is to determine factors that can help to predict the Alveolar Bone reaction before maxillary incisor intrusion and retraction. The cohort included 34 female patients (mean age 25.8 years) who were diagnosed with skeletal class II malocclusion with upper incisor protrusion. These patients underwent extraction and orthodontic treatment with upper incisor intrusion and retraction. Lateral cephalograms at pre-treatment and post-treatment were taken. Linear and angular measurements were analyzed to evaluate the Alveolar Bone changes based on initial conditions. The study found that the relative change, calculated as change in Alveolar Bone thickness after treatment divided by the initial Alveolar thickness, was inversely correlated with the initial thickness. There was a significant increase of labial Alveolar Bone thickness at 9-mm apical from cementoenamel junction (B3) (P < 0.05) but no statistically significant change in the thickness at other levels. In addition, the change in angulation between the incisor and Alveolar Bone was inversely correlated with several initial angulations: between the initial palatal plane and upper incisor angle, between the initial palatal plane and upper incisor labial surface angle, and between the initial palatal plane and Bone labial surface angle. On the other hand, the change in labial Bone thickness was neither significantly correlated with the initial thickness nor significantly correlated to the amount of retraction. The unpredictability of Alveolar Bone remodeling after upper incisor intrusion and retraction poses significant challenges to treatment planning and patient experience. The study showed that the initial angulation between the incisor and Alveolar Bone is correlated with the change in angulation after treatment, the initial thickness of the Alveolar Bone was correlated with the relative change of the Alveolar Bone thickness (defined as change in thickness after treatment divided by its initial thickness), and the amount of intrusion was correlated with the Alveolar Bone thickness change at 9-mm apical from the cementoenamel junction after treatment. The results of the present study also revealed that the change in labial Alveolar Bone thickness was neither significantly correlated with the initial thickness nor significantly correlated to the amount of retraction.
Mikako Tanaka - One of the best experts on this subject based on the ideXlab platform.
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Effects of ovariectomy on trabecular structures of rat Alveolar Bone
Clinical calcium, 2003Co-Authors: Mikako Tanaka, Shoji Kohno, Sadakazu EjiriAbstract:To clarify the relationship between estrogen deficiency and tooth loss, we analyzed the trabecular structural changes of mandibular Alveolar Bone in ovariectomized rats. Two months after ovariectomy, the Bone resorptive activity remarkably accelerated and caused high Bone turnover. On the other hand, one year after ovariectomy, Bone loss and trabecular fragmentation occurred in the Alveolar Bone, although the accelerated degree of Bone resorptive activity was moderate. If elderly women could experience similar changes on their Alveolar Bone, we must pay more attention to the Bone resorption presently after menopause and the trabecular fragility long after menopause.
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Effects of ovariectomy on trabecular structures of rat Alveolar Bone
Journal of periodontal research, 2002Co-Authors: Mikako Tanaka, Shoji Kohno, Sadakazu Ejiri, E. Toyooka, Hidehiro OzawaAbstract:An association between postmenopausal osteoporosis and tooth loss has been proposed. However, histomorphometrical changes in Alveolar Bone following estrogen deficiency are rarely reported with data on microtrabecular structural changes. To clarify the relationship between estrogen deficiency and tooth loss, we histomorphometrically analyzed the trabecular structural changes of mandibular Alveolar Bone in ovariectomized rats. Twenty-four adult female Fischer rats were used. Eight rats were sacrificed on day 0 (baseline). The remaining 16 rats were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other group was subjected to sham surgery (Sham). After administration of tetracycline and calcein, the animals were sacrificed 60 days after surgery. Bone histomorphometry, node-strut analysis and measurement of thickness of Alveolar Bone proper were performed on the interradicular septum of the first molar on the sagittal surface. The trabecular Bone volume and trabecular number of the OVX group were significantly lower than those of the baseline and Sham groups. All of the Bone resorptive and formative parameters of the OVX group were significantly higher (about one-and-a-half times) than those of the Sham group. Several osteoclasts were seen lining the irregular, eroded surface facing the Bone marrow in the OVX group. Furthermore, the OVX group tended to have low microtrabecular stiffness and showed significantly thinner distal Alveolar Bone proper than in the baseline and Sham groups. In summary, estrogen deficiency caused osteoporotic changes and thin Alveolar Bone proper in the interradicular septum of rat first molar. This phenomenon might accelerate destruction of Alveolar Bone and tooth loss, especially in elderly women affected by periodontal disease.
Reinhard Gruber - One of the best experts on this subject based on the ideXlab platform.
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Osteoimmunology: Inflammatory osteolysis and regeneration of the Alveolar Bone.
Journal of Clinical Periodontology, 2019Co-Authors: Reinhard GruberAbstract:Aim Osteoimmunology covers the cellular and molecular mechanisms responsible for inflammatory osteolysis that culminates in the degradation of Alveolar Bone. Osteoimmunology also focuses on the interplay of immune cells with Bone cells during Bone remodelling and regeneration. The aim of this review was to provide insights into how osteoimmunology affects Alveolar Bone health and disease. Method This review is based on a narrative approach to assemble mouse models that provide insights into the cellular and molecular mechanisms causing inflammatory osteolysis and on the impact of immune cells on Alveolar Bone regeneration. Results Mouse models have revealed the molecular pathways by which microbial and other factors activate immune cells that initiate an inflammatory response. The inflammation-induced Alveolar Bone loss occurs with the concomitant suppression of Bone formation. Mouse models also showed that immune cells contribute to the resolution of inflammation and Bone regeneration, even though studies with a focus on Alveolar socket healing are rare. Conclusions Considering that osteoimmunology is evolutionarily conserved, osteolysis removes the cause of inflammation by provoking tooth loss. The impact of immune cells on Bone regeneration is presumably a way to reinitiate the developmental mechanisms of intramembranous and endochondral Bone formation.
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Osteoimmunology: Inflammatory osteolysis and regeneration of the Alveolar Bone.
Journal of clinical periodontology, 2019Co-Authors: Reinhard GruberAbstract:Osteoimmunology covers the cellular and molecular mechanisms responsible for inflammatory osteolysis that culminates in the degradation of Alveolar Bone. Osteoimmunology also focuses on the interplay of immune cells with Bone cells during Bone remodelling and regeneration. The aim of this review was to provide insights into how osteoimmunology affects Alveolar Bone health and disease. This review is based on a narrative approach to assemble mouse models that provide insights into the cellular and molecular mechanisms causing inflammatory osteolysis and on the impact of immune cells on Alveolar Bone regeneration. Mouse models have revealed the molecular pathways by which microbial and other factors activate immune cells that initiate an inflammatory response. The inflammation-induced Alveolar Bone loss occurs with the concomitant suppression of Bone formation. Mouse models also showed that immune cells contribute to the resolution of inflammation and Bone regeneration, even though studies with a focus on Alveolar socket healing are rare. Considering that osteoimmunology is evolutionarily conserved, osteolysis removes the cause of inflammation by provoking tooth loss. The impact of immune cells on Bone regeneration is presumably a way to reinitiate the developmental mechanisms of intramembranous and endochondral Bone formation. © 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Sadakazu Ejiri - One of the best experts on this subject based on the ideXlab platform.
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Effects of ovariectomy on trabecular structures of rat Alveolar Bone
Clinical calcium, 2003Co-Authors: Mikako Tanaka, Shoji Kohno, Sadakazu EjiriAbstract:To clarify the relationship between estrogen deficiency and tooth loss, we analyzed the trabecular structural changes of mandibular Alveolar Bone in ovariectomized rats. Two months after ovariectomy, the Bone resorptive activity remarkably accelerated and caused high Bone turnover. On the other hand, one year after ovariectomy, Bone loss and trabecular fragmentation occurred in the Alveolar Bone, although the accelerated degree of Bone resorptive activity was moderate. If elderly women could experience similar changes on their Alveolar Bone, we must pay more attention to the Bone resorption presently after menopause and the trabecular fragility long after menopause.
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Effects of ovariectomy on trabecular structures of rat Alveolar Bone
Journal of periodontal research, 2002Co-Authors: Mikako Tanaka, Shoji Kohno, Sadakazu Ejiri, E. Toyooka, Hidehiro OzawaAbstract:An association between postmenopausal osteoporosis and tooth loss has been proposed. However, histomorphometrical changes in Alveolar Bone following estrogen deficiency are rarely reported with data on microtrabecular structural changes. To clarify the relationship between estrogen deficiency and tooth loss, we histomorphometrically analyzed the trabecular structural changes of mandibular Alveolar Bone in ovariectomized rats. Twenty-four adult female Fischer rats were used. Eight rats were sacrificed on day 0 (baseline). The remaining 16 rats were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other group was subjected to sham surgery (Sham). After administration of tetracycline and calcein, the animals were sacrificed 60 days after surgery. Bone histomorphometry, node-strut analysis and measurement of thickness of Alveolar Bone proper were performed on the interradicular septum of the first molar on the sagittal surface. The trabecular Bone volume and trabecular number of the OVX group were significantly lower than those of the baseline and Sham groups. All of the Bone resorptive and formative parameters of the OVX group were significantly higher (about one-and-a-half times) than those of the Sham group. Several osteoclasts were seen lining the irregular, eroded surface facing the Bone marrow in the OVX group. Furthermore, the OVX group tended to have low microtrabecular stiffness and showed significantly thinner distal Alveolar Bone proper than in the baseline and Sham groups. In summary, estrogen deficiency caused osteoporotic changes and thin Alveolar Bone proper in the interradicular septum of rat first molar. This phenomenon might accelerate destruction of Alveolar Bone and tooth loss, especially in elderly women affected by periodontal disease.
