WHO将骨质疏松定义为一种骨密度降低,并且骨微结构改变的疾病。当前,骨密度（bone mineral density,BMD）双能X线骨密度仪（DXA）的测量（通常是在椎骨或股骨颈部）已经成为了评定骨质疏松症的重要方法[1]。但是,将近一半的骨折病人并...WHO将骨质疏松定义为一种骨密度降低,并且骨微结构改变的疾病。当前,骨密度（bone mineral density,BMD）双能X线骨密度仪（DXA）的测量（通常是在椎骨或股骨颈部）已经成为了评定骨质疏松症的重要方法[1]。但是,将近一半的骨折病人并没有达到诊断为骨质疏松症的BMD标准。越来越多的BMD没有问题的成年人处于骨折的风险下;很多T值在-2.5SD以上的妇女也发生了骨折。这说明,如果要准确地预测骨折发生的可能。展开更多
Objective:This study aimed to explore the effects of different types of palatal lateral excisions on the growth and development of the maxilla and dental arch, and to investigate the underlying mechanisms. Methods: A ...Objective:This study aimed to explore the effects of different types of palatal lateral excisions on the growth and development of the maxilla and dental arch, and to investigate the underlying mechanisms. Methods: A total of 112 3-week-old Sprague-Dawley (SD) male rats were randomly divided into a control and 3 experimental groups: the mucoperiosteal denudation group, the mucosal flap excision group, and the periosteum excision group. In the experimental groups, bilateral mucoperiosteal, mucosal flap and periosteum were excised respectively in the lateral one half of the palate. Four rats in each group were randomly chosen for sacrifice every two weeks. The maxilla was dissected following the excision. The widths of the maxilla and dental arch were measured and the histological phenomena were investigated at different phases. At the same time, 12 animals in each group were sequentially injected with calcein every two weeks. Three animals in each group, whose fluorescent labeling was used, were sacrificed for investigating bone formation at Week 8 following injection. Results: (1) Each experimental group presented the constriction of the maxilla and dental arch. The upper first molars in the experimental groups inclined medially. The mucoperio-steal denudation group showed the largest degree of effect followed by the periosteum excision group. The indices of the mucosal flap excision group, which retained the structures of the periosteum layer, had the most approximate values to the control group; (2) Different histological changes among the experimental groups were detected. The fibers penetrated into the palatal bone as Sharpey's fibers in the mucoperiosteal denudation group. The pattern of bone deposition was the bundle type. Sharpey's fibers were not found in the mucosal flap and periosteum excision groups and the depositions of palatal bone were the lamellar type as those in the control group; (3) The rates of bone deposition in the experimental groups decreased compared with the control group. The rates in different phases were the most approximate values to those of the control group in the mucosal flap excision group, which has the same structure of periosteum as the control group. Conclusion: There were different effects on the growth and development of the maxilla and dental arch in different types of palatal lateral excisions. Periosteum is important for bone for-mation and deposition pattern. The prevention of Sharpey's fibers forming and attaching to the palatine can effectively avert the following malformation.展开更多
Objective： The aim of our study was to compare the value of computed tomography （CT） and 99mTc-methylene- diphosphonate （MDP） SPECT （single photon emission computed tomography）/CT fusion imaging in determining ...Objective： The aim of our study was to compare the value of computed tomography （CT） and 99mTc-methylene- diphosphonate （MDP） SPECT （single photon emission computed tomography）/CT fusion imaging in determining the extent of mandibular invasion by malignant tumor of the oral cavity. Methods： This study had local ethical committee approval, and all patients gave written informed consent. Fifty-three patients were revealed mandibular invasion by malignant tumor of the oral cavity underwent CT and SPECT/CT. The patients were divided into two groups： group A （invasion-periphery-type） and group B （invasion-center- type）. Two radiologists assessed the CT images and two nuclear medicine physicians separately assessed the $PECT/CT images in consensus and without knowledge of the results of other imaging tests. The extent of bone involvement suggested with an imaging modality was compared with pathological findings in the surgical specimen. Results： With pathological findings as the standard of reference, Group A： The extent of mandibular invasion by malignant tumor under- went SPECT/CT was 1.02 _＋ 0.20 cm larger than that underwent pathological findings. And the extent of mandibular invasion underwent CT was 1.42 ＋ 0.35 cm smaller than that underwent pathological examination. There were significant difference among the three methods （P 〈 0.01）. Group B： The extent of mandibular invasion by malignant tumor underwent SPECT/CT was 1.3 ＋ 0.39 cm larger than that underwent pathological examination. The extent of mandibular invasion underwent CT was 2.55 ＋ 1.44 cm smaller than that underwent pathological findings. There were significant difference among the three methods （P 〈 0.01）. The extent of mandibular invasion underwent SPECT/CT was the extent which surgeon must excise to get clear margins. Conclusion： SPECT/CT fusion imaging has significant clinical value in determining the extent of mandibular inva- sion by malignant tumor of oral cavity.展开更多
文摘WHO将骨质疏松定义为一种骨密度降低,并且骨微结构改变的疾病。当前,骨密度（bone mineral density,BMD）双能X线骨密度仪（DXA）的测量（通常是在椎骨或股骨颈部）已经成为了评定骨质疏松症的重要方法[1]。但是,将近一半的骨折病人并没有达到诊断为骨质疏松症的BMD标准。越来越多的BMD没有问题的成年人处于骨折的风险下;很多T值在-2.5SD以上的妇女也发生了骨折。这说明,如果要准确地预测骨折发生的可能。
文摘Objective:This study aimed to explore the effects of different types of palatal lateral excisions on the growth and development of the maxilla and dental arch, and to investigate the underlying mechanisms. Methods: A total of 112 3-week-old Sprague-Dawley (SD) male rats were randomly divided into a control and 3 experimental groups: the mucoperiosteal denudation group, the mucosal flap excision group, and the periosteum excision group. In the experimental groups, bilateral mucoperiosteal, mucosal flap and periosteum were excised respectively in the lateral one half of the palate. Four rats in each group were randomly chosen for sacrifice every two weeks. The maxilla was dissected following the excision. The widths of the maxilla and dental arch were measured and the histological phenomena were investigated at different phases. At the same time, 12 animals in each group were sequentially injected with calcein every two weeks. Three animals in each group, whose fluorescent labeling was used, were sacrificed for investigating bone formation at Week 8 following injection. Results: (1) Each experimental group presented the constriction of the maxilla and dental arch. The upper first molars in the experimental groups inclined medially. The mucoperio-steal denudation group showed the largest degree of effect followed by the periosteum excision group. The indices of the mucosal flap excision group, which retained the structures of the periosteum layer, had the most approximate values to the control group; (2) Different histological changes among the experimental groups were detected. The fibers penetrated into the palatal bone as Sharpey's fibers in the mucoperiosteal denudation group. The pattern of bone deposition was the bundle type. Sharpey's fibers were not found in the mucosal flap and periosteum excision groups and the depositions of palatal bone were the lamellar type as those in the control group; (3) The rates of bone deposition in the experimental groups decreased compared with the control group. The rates in different phases were the most approximate values to those of the control group in the mucosal flap excision group, which has the same structure of periosteum as the control group. Conclusion: There were different effects on the growth and development of the maxilla and dental arch in different types of palatal lateral excisions. Periosteum is important for bone for-mation and deposition pattern. The prevention of Sharpey's fibers forming and attaching to the palatine can effectively avert the following malformation.
文摘Objective： The aim of our study was to compare the value of computed tomography （CT） and 99mTc-methylene- diphosphonate （MDP） SPECT （single photon emission computed tomography）/CT fusion imaging in determining the extent of mandibular invasion by malignant tumor of the oral cavity. Methods： This study had local ethical committee approval, and all patients gave written informed consent. Fifty-three patients were revealed mandibular invasion by malignant tumor of the oral cavity underwent CT and SPECT/CT. The patients were divided into two groups： group A （invasion-periphery-type） and group B （invasion-center- type）. Two radiologists assessed the CT images and two nuclear medicine physicians separately assessed the $PECT/CT images in consensus and without knowledge of the results of other imaging tests. The extent of bone involvement suggested with an imaging modality was compared with pathological findings in the surgical specimen. Results： With pathological findings as the standard of reference, Group A： The extent of mandibular invasion by malignant tumor under- went SPECT/CT was 1.02 _＋ 0.20 cm larger than that underwent pathological findings. And the extent of mandibular invasion underwent CT was 1.42 ＋ 0.35 cm smaller than that underwent pathological examination. There were significant difference among the three methods （P 〈 0.01）. Group B： The extent of mandibular invasion by malignant tumor underwent SPECT/CT was 1.3 ＋ 0.39 cm larger than that underwent pathological examination. The extent of mandibular invasion underwent CT was 2.55 ＋ 1.44 cm smaller than that underwent pathological findings. There were significant difference among the three methods （P 〈 0.01）. The extent of mandibular invasion underwent SPECT/CT was the extent which surgeon must excise to get clear margins. Conclusion： SPECT/CT fusion imaging has significant clinical value in determining the extent of mandibular inva- sion by malignant tumor of oral cavity.
