Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, wh...Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.展开更多
目的探讨成人骨型Ⅲ类患者矫治前后上下前牙区牙槽高度和宽度变化以及前牙区牙根位置变化。方法选取2020年5月—2022年11月在中山市小榄人民医院口腔科正畸掩饰治疗的成人骨型Ⅲ类患者50例,比较正畸治疗前后患者上下颌前牙牙槽骨厚度和...目的探讨成人骨型Ⅲ类患者矫治前后上下前牙区牙槽高度和宽度变化以及前牙区牙根位置变化。方法选取2020年5月—2022年11月在中山市小榄人民医院口腔科正畸掩饰治疗的成人骨型Ⅲ类患者50例,比较正畸治疗前后患者上下颌前牙牙槽骨厚度和高度,其中包括上前牙槽骨厚度(upper anterior alveolar bonethickness,UA)、上后牙槽骨厚度(upper posterior alveolar bone thickness,UP)、上牙槽骨总厚度(upper alveolar bone width,UW)、下前牙槽骨厚度(lower anterior alveolar bone thickness,LA)、下后牙槽骨厚度(lower posterior alveolar bone thickness,LP)、下牙槽骨总厚度(lower alveolar bone width,LW)、根中水平上前牙槽骨厚度(upper anterior alveolar bone thickness at the mid-root level,UA-m)、根中水平上后牙槽骨厚度(upper posterior alveolar bone thickness at the mid-root level,UP-m)、根中水平上牙槽骨总厚度(upper alveolar bone thickness at the mid-root level,UW-m)、根中水平下前牙槽骨厚度(lower anterior alveolar bone thickness at the mid-root level,LA-m)、根中水平下后牙槽骨厚度(lower posterior alveolar bone thickness at the mid-root level,LP-m)、根中水平下牙槽骨总厚度(lower alveolar bone thickness at the mid-root level,LW-m)以及上前牙槽骨高度(upper anterior alveolar bone height,UAH)和下前牙槽骨高度(lower anterior alveolarbone height,LAH)。结果正畸治疗前后患者UA、UP-m测量值比较,差异无统计学意义(P>0.05)。与正畸治疗前比较,正畸治疗后患者UP、UW、UA-m、UW-m测量值均显著降低(P<0.05)。正畸治疗后患者LP、LA-m测量值与正畸治疗前比较,差异无统计学意义(P>0.05)。与正畸治疗前比较,正畸治疗后患者LA、LW、LP-m、LW-m测量值均降低(P<0.05)。与正畸治疗前比较,正畸治疗后患者UAH、LAH测量值均显著降低(P<0.05)。正畸治疗后,患者上下颌前牙解剖牙根长度分别为(10.62±0.57)mm、(9.65±0.48)mm,正畸治疗前患者上下颌前牙解剖牙根长度分别为(11.01±0.58)mm、(10.37±0.48)mm,与正畸治疗前比较,患者上下颌前牙解剖牙根长度明显减小(P<0.05)。结论成人骨型Ⅲ类患者进行正畸掩饰治疗后,牙槽形态会发生相应改变,患者上下前牙牙槽骨厚度和高度会一定程度地减少。因此,在矫治过程中应当对患者牙槽形态的变化给予密切关注,尽量避免上下前牙发生代偿性移动,从而降低不良反应情况发生的风险。展开更多
文摘Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.
文摘目的探讨成人骨型Ⅲ类患者矫治前后上下前牙区牙槽高度和宽度变化以及前牙区牙根位置变化。方法选取2020年5月—2022年11月在中山市小榄人民医院口腔科正畸掩饰治疗的成人骨型Ⅲ类患者50例,比较正畸治疗前后患者上下颌前牙牙槽骨厚度和高度,其中包括上前牙槽骨厚度(upper anterior alveolar bonethickness,UA)、上后牙槽骨厚度(upper posterior alveolar bone thickness,UP)、上牙槽骨总厚度(upper alveolar bone width,UW)、下前牙槽骨厚度(lower anterior alveolar bone thickness,LA)、下后牙槽骨厚度(lower posterior alveolar bone thickness,LP)、下牙槽骨总厚度(lower alveolar bone width,LW)、根中水平上前牙槽骨厚度(upper anterior alveolar bone thickness at the mid-root level,UA-m)、根中水平上后牙槽骨厚度(upper posterior alveolar bone thickness at the mid-root level,UP-m)、根中水平上牙槽骨总厚度(upper alveolar bone thickness at the mid-root level,UW-m)、根中水平下前牙槽骨厚度(lower anterior alveolar bone thickness at the mid-root level,LA-m)、根中水平下后牙槽骨厚度(lower posterior alveolar bone thickness at the mid-root level,LP-m)、根中水平下牙槽骨总厚度(lower alveolar bone thickness at the mid-root level,LW-m)以及上前牙槽骨高度(upper anterior alveolar bone height,UAH)和下前牙槽骨高度(lower anterior alveolarbone height,LAH)。结果正畸治疗前后患者UA、UP-m测量值比较,差异无统计学意义(P>0.05)。与正畸治疗前比较,正畸治疗后患者UP、UW、UA-m、UW-m测量值均显著降低(P<0.05)。正畸治疗后患者LP、LA-m测量值与正畸治疗前比较,差异无统计学意义(P>0.05)。与正畸治疗前比较,正畸治疗后患者LA、LW、LP-m、LW-m测量值均降低(P<0.05)。与正畸治疗前比较,正畸治疗后患者UAH、LAH测量值均显著降低(P<0.05)。正畸治疗后,患者上下颌前牙解剖牙根长度分别为(10.62±0.57)mm、(9.65±0.48)mm,正畸治疗前患者上下颌前牙解剖牙根长度分别为(11.01±0.58)mm、(10.37±0.48)mm,与正畸治疗前比较,患者上下颌前牙解剖牙根长度明显减小(P<0.05)。结论成人骨型Ⅲ类患者进行正畸掩饰治疗后,牙槽形态会发生相应改变,患者上下前牙牙槽骨厚度和高度会一定程度地减少。因此,在矫治过程中应当对患者牙槽形态的变化给予密切关注,尽量避免上下前牙发生代偿性移动,从而降低不良反应情况发生的风险。
